technetium-tc-99m-exametazime and Dementia

Over the last decade the interest towards functional neuroimaging has gradually increased, especially in the field of neurodegenerative diseases. At present, diagnosis of dementia is mostly clinical. Numerous modalities of neuroimaging are today available, each of them allowing a different aspect of neurodegeneration to be investigated. Although during the last period many have predicted a forthcoming disappearance of SPECT imaging in favour of the PET imaging, many new radiotracers SPECT, dual-SPECT tracers techniques and receptor targeting designed radiopharmaceuticals are currently at study. Besides, last decade has also assisted to the development of new SPECT imaging systems, most of them integrated with other imaging modalities (MRI, CT, ultrasound techniques), granting improved imaging capabilities. All these improved conditions, especially appealing for the neuroimaging, together with the new radiopharmaceuticals in development may renovate the interest for SPECT clinical applications.

Topics: Cysteine; Dementia; Functional Neuroimaging; Humans; Magnetic Resonance Imaging; Organotechnetium Compounds; Positron-Emission Tomography; Practice Guidelines as Topic; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Investigators have reported high sensitivity and specificity values for single photon emission computerized tomography (SPECT) when distinguishing Alzheimer's disease (AD) patients from normal elderly controls or from selected patient groups. The role of SPECT in identifying AD among unselected patients with memory complaints requires investigation. We examined 139 consecutive patients with 99Tc-HMPAO SPECT. NINCDS-ADRDA diagnoses were determined blind to SPECT results, and scans were read and classified by visual inspection blind to clinical diagnoses. Bilateral temporoparietal hypoperfusion (TP) occurred in 75% of probable, 65% of possible, and 45% of unlikely AD patients, yielding a sensitivity of 75% and a specificity of 52% when comparing probable AD versus unlikely AD groups. A positive predictive value of 78% was obtained based on a 69% prevalence of AD in our total clinic population. Patients with false-positive results included a variety of dementing illnesses; all patients with bilateral hypoperfusion had dementia. A pattern of TP on SPECT scans is seen in most patients with AD, but could be found in other dementias as well and cannot be regarded as specific to AD. Reduced TP perfusion discriminated between demented and nondemented individuals. Further strategies for SPECT interpretation that improve diagnostic specificity should be sought.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Dementia; Dementia, Vascular; Diagnosis, Differential; Dominance, Cerebral; Humans; Organotechnetium Compounds; Oximes; Parietal Lobe; Reference Values; Regional Blood Flow; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Brain imaging has become an integral part of the evaluation of neurological and psychiatric disorders. Functional imaging techniques, SPECT and PET, together with structural modalities, CT and MRI, are widely employed. Functional imaging studies are routinely used in the diagnostic workup of patients with well-characterized neurological disorders, such as epilepsy and brain tumors, and have a growing role in research on psychiatric disorders without known mechanisms such as depression and schizophrenia. Furthermore, many well-defined neurological disorders manifest prominent psychiatric symptomatology which may pose difficulties in differential diagnosis. This review addresses the current knowledge of SPECT findings in patients who present with psychiatric phenomena, associated with disorders at the interface of neurology and psychiatry.

Topics: Alzheimer Disease; Brain; Brain Damage, Chronic; Brain Diseases; Brain Injuries; Brain Neoplasms; Dementia; Diagnosis, Differential; Epilepsy, Temporal Lobe; Humans; Huntington Disease; Neurocognitive Disorders; Organotechnetium Compounds; Oximes; Parkinson Disease; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

This review critically evaluates the current role of single photon emission tomography (SPET) imaging in the clinical management of patients with dementia. The classification of the dementias is discussed and the clinical and pathological features of the various dementing illnesses are described. Typical appearances on cerebral blood flow imaging are presented for each of the conditions, together with the findings on D2 dopaminergic receptor and muscarinic receptor imaging where this is relevant. The review concludes with a section on the clinical value of SPET imaging in dementia. SPET imaging can make a valuable contribution to the accurate clinical differentiation of dementia, providing findings are interpreted in the light of neurological evaluation and structural imaging. The possible future role of SPET imaging in the prediction and evaluation of response to future therapeutic agents is discussed.

Topics: Alzheimer Disease; Brain; Brain Diseases; Dementia; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Three cases of rapid onset neuropsychological frontal dementia preceded the development of sporadic amyotrophic lateral sclerosis by 12 to 24 months. HmPAO Tc99m scintigraphy demonstrated hypoactivity in the cortex, predominantly in the frontal region. Three hypotheses are discussed: 1) coincidence between two degenerative diseases, Alzheimer's disease or Pick's disease and ALS; 2) an amyotrophic form of Creutzfeld Jakob disease; 3) pre-senile dementia associated with a motoneuron disease, a clinical pathology entity recently described by Mitzuyama.

Topics: Aged; Amyotrophic Lateral Sclerosis; Dementia; Frontal Lobe; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Functional imaging studies in patients with dementia have focused primarily on the reliability of scan patterns to correctly diagnose specific diseases, particularly Alzheimer's disease. Results from these studies have important implications as disease-specific treatments become available. A complementary approach is to examine the relationships between patterns of altered brain function and specific behaviors. This tactic has potential impact on understanding normal brain organization as well as targeting symptom-specific treatments. Regional abnormalities have been identified in dementia patients that correlate with specific behavioral deficits: disturbances of language and visuospatial function, impaired verbal fluency and selective attention, and the presence of delusions and depression. These patterns are seen in patients with Alzheimer's disease as well as with dementias of other etiologies. The specificity of these patterns for disease-specific and disease-independent symptoms is unknown.

Topics: Alzheimer Disease; Brain; Cognition Disorders; Delusions; Dementia; Deoxyglucose; Depressive Disorder; Diagnosis, Differential; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Severity of Illness Index; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The most common cause of dementia in the developed world is Alzheimer's disease. Histopathology is required to confirm diagnosis, but most evaluations of the accuracy of clinical criteria and neuroimaging in the diagnosis of dementia of the Alzheimer type are without such confirmation. The average specificity of clinical criteria alone is about 75%. This paper discusses the contribution of simple structural (x-ray computed tomography [CT]) and functional (Tc-99m-HMPAO single photon emission computed tomography [SPECT]) imaging to the diagnosis of Alzheimer's disease in 71 histopathologically confirmed cases (47 with Alzheimer's disease, 16 with other dementias, 8 controls) and 84 living controls. Medial temporal lobe atrophy assessed by temporal lobe-oriented CT gave 94% sensitivity and 93% specificity, while parietotemporal hypoperfusion on SPECT revealed 96% sensitivity and 89% specificity. The combination of both changes yielded a sensitivity of 90% and a specificity of 97%. These investigations clearly enhance diagnostic accuracy, can be readily applied in the clinical situation, and could be used in epidemiologic studies of Alzheimer's disease.

Topics: Alzheimer Disease; Dementia; Diagnosis, Differential; Humans; Magnetic Resonance Imaging; Organotechnetium Compounds; Oximes; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The imaging of regional cerebral blood flow (rCBF) by 99mTc-d, 1 HM-PAO and SPECT is described. Its relevance to clinical syndromes, such as stroke, transient ischemic attacks, various forms of dementia, epilepsy, and subarachnoid hemorrhage, is reported.

Topics: Animals; Brain; Cerebrovascular Circulation; Cerebrovascular Disorders; Chemical Phenomena; Chemistry; Dementia; Epilepsy; Humans; Ischemic Attack, Transient; Organometallic Compounds; Organotechnetium Compounds; Oximes; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

This study was designed to quantify the heterogeneity on cerebral blood flow single-photon emission tomography (SPET) images in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) using a three-dimensional fractal analysis. Twenty-one FTLD patients, 21 AD patients and 11 healthy controls underwent technetium-99m hexamethylpropylene amine oxime SPET scanning. Patients with FTLD and AD matched for sex, age and the severity of dementia as estimated with the Clinical Dementia Rating and were determined to be in the early stage of illness. We delineated the SPET images using a 35% cut-off and a 50% cut-off of the maximal voxel radioactivity and measured the number of voxels included in the contours of two different cut-offs. The fractal dimension (FD) was calculated by relating the logarithms of the cut-offs and the numbers of voxels, and it was defined as the heterogeneity of the cerebral perfusion. We divided the SPET images into two sets, anterior and posterior, with equal numbers of coronal SPET slices. We calculated total FD, anterior FD and posterior FD for total, anterior and posterior SPET images. Anterior FDs for FTLD and AD were 1.55 +/- 0.34 and 1.24 +/- 0.19 (P = 0.0002). The ratios of anterior to posterior FD for FTLD and AD were 1.81 +/- 0.41 and 1.32 +/- 0.14 (P < 0.0001). Use of the anterior FD and the ratio of anterior to posterior FD separated FTLD patients from AD patients and controls with a sensitivity of 85.7% and a specificity of 93.8%. Anterior FD and the ratio of anterior to posterior FD may be useful in distinguishing FTLD from AD.

Topics: Aged; Alzheimer Disease; Blood Flow Velocity; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Female; Fractals; Humans; Imaging, Three-Dimensional; Male; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Hypoperfusion in the posterior cingulate cortex is thought to be useful for the early diagnosis of dementia of Alzheimer type (DAT). In the present study, we compared the incidence of posterior cingulate hypoperfusion in patients with Alzheimer's disease (AD), patients with senile dementia of Alzheimer type (SDAT), and patients with other types of dementia, as evaluated by three-dimensional stereotactic surface projection (3D-SSP) imaging. The subjects were 20 AD patients, 20 SDAT patients, 13 frontotemporal dementia patients, and 3 other types of dementia patients. A SPECT study was performed 5 minutes after the injection of 740 MBq technetium-99m hexamethylpropylene amine oxime. 3D-SSP images were obtained with global normalization to perform the statistical analysis. The normal database of 3D-SSP consisted of 15 healthy volunteers. Hypoperfusion was considered to be significant when the Z-score was over 2.5. Posterior cingulate hypoperfusion was observed in 13 of 20 AD patients (65%), in 5 of 20 SDAT patients (25%), but in none of other type of dementia patients. Posterior cingulate hypoperfusion was considered to be a finding specific to DAT, and this finding was thought to be useful to diagnose DAT patients, especially for AD patients. However, it was considered to be difficult to diagnose early-stage SDAT patients.

Topics: Aged; Alzheimer Disease; Brain Ischemia; Cerebrovascular Circulation; Dementia; Female; Gyrus Cinguli; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Male; Middle Aged; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Characteristic patterns of regional cerebral blood flow (rCBF) reduction, as detected by technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO) single-photon emission tomography (SPET), may help clinicians in differentiating patients with frontotemporal dementia (FTD) from those with Alzheimer's disease (AD). However, in some cases these patients may share common rCBF abnormalities and the visual analysis and/or the region of interest (ROI) approach may not sensitively detect more localised focal changes that could be more specific for each pathology. Recently, automated voxel-by-voxel statistical analysis of perfusion brain maps has been applied to SPET images. This method has the advantage of including the rCBF information for the whole brain for statistical analysis without any a priori hypothesis regarding the regions possibly involved. This could result in a better characterisation of rCBF differences in brain regions while also reducing the operator's subjectivity and the time required for data analysis. The purpose of this study was to apply such a technique to highlight the specific brain areas showing a relative functional involvement in FTD and AD. Thus, we compared the relative rCBF patterns obtained in eight FTD patients with those obtained in 21 AD patients using (99m)Tc-HMPAO SPET and statistical parametric mapping (SPM). When FTD patients were compared with AD patients, relatively lower rCBF was observed in right medial frontal cortex (BA 8, 9, 10), right anterior cingulate cortex (BA 32), right temporal cortex (BA 21/22), right orbitofrontal cortex (BA 11) and ventrolateral prefrontal cortex (BA 47); in BA 47 the reduction was evident bilaterally but was more marked on the right side. On the other hand, when AD patients were compared with FTD patients, a significant relative rCBF decrease was found in the bilateral superior parietal cortex (BA 7); this decrease was more extensive on the left side, where it also included the inferior parietal (BA 40), superior occipital (BA 19) and temporo-occipital regions (BA 39, 19). The results of this study confirm the preferential involvement of the frontotemporal regions in FTD patients and of the temporoparietal regions in AD patients. Furthermore, they highlight the networks that are more specifically impaired in these disorders and that could be implicated in the emotional-behavioural and cognitive disturbances that characterise FTD and AD respectively.

Topics: Aged; Alzheimer Disease; Cerebral Cortex; Cerebrovascular Circulation; Dementia; Female; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Male; Nerve Net; Radiopharmaceuticals; Subtraction Technique; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors examined the presence of specific quantified electroencephalographic (qEEG) changes in dementia patients with relatively lower frontal or parietal blood perfusion as demonstrated by SPECT. Over all brain regions, patients with relatively lower parietal perfusion showed significantly higher theta relative power than demented patients with relatively lower frontal perfusion or normal control subjects. Dementia patients with relatively lower frontal perfusion showed no differences from age-comparable normal control subjects in qEEG variables. These findings 1) suggest that usefulness of qEEG for the diagnosis of dementia is restricted to a subgroup of patients with the typical SPECT pattern of parietal blood hypoperfusion and 2) demonstrate that the qEEG changes typical of dementia are not related to perfusion deficits in frontal brain areas.

Topics: Aged; Alzheimer Disease; Cerebrovascular Circulation; Dementia; Electroencephalography; Female; Fourier Analysis; Frontal Lobe; Humans; Male; Neurologic Examination; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Parietal Lobe; Psychiatric Status Rating Scales; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In order to synthesize three-dimensional information on relative regional blood flow (rCBF) from the cortical grey matter in 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission tomographic (SPET) images into a single two-dimensional 'cortical peel' (CP) image, we developed a program that performs cylindrical transformation of SPET data. A sub-routine of this program performs measurements of cortex-to-cerebellum rCBF ratios for 54 cortical regions in the CP image. This program was used to establish a normative database derived from 30 young normal control subjects aged 28.7 +/- 6.9 years. The database was then used to express cortex-to-cerebellum rCBF ratios in four colour-coded ranges of normal standard deviation of the mean rCBF ratio across the cortical regions in the CP image. This CP method was implemented for 30 clinical HMPAO SPET studies in patients (n = 30, aged 71.8 +/- 4.2 years) with suspected dementia as well as several studies in aged healthy subjects (n = 8, aged 67 +/- 9.8 years). In 25/30 (83%) patients, all abnormalities seen on the tomographic display were evident on the corresponding CP image. No aged healthy subjects showed abnormalities on either the tomographic display or the corresponding CP image. An advantage of this technique is that the extent and severity of rCBF abnormalities are readily appreciated in one single image. This technique, in conjunction with the conventional multi-slice tomographic display, was a useful tool in identifying various patterns of rCBF abnormalities in the patients with clinically suspected dementia.

Topics: Adult; Aged; Aging; Brain Mapping; Cerebellum; Cerebral Cortex; Cerebrovascular Circulation; Databases, Factual; Dementia; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organotechnetium Compounds; Oximes; Reference Values; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In a prospective MRI study the presence, appearance, volume, and regional cerebral blood flow (rCBF) correlates of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) were examined in 18 patients with probable Alzheimer's disease and in 10 age matched healthy control subjects, all without major cerbrovascular risk factors. The 133Xe inhalation method and the [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) technique with single photon emission computed tomography (SPECT) were used to measure rCBF. Rating scores for PVHs were significantly higher in the Alzheimer's disease group (p < 0.01) and correlated significantly with the volume of ventricles (p < 0.05) and with systolic arterial blood pressure (p < 0.01), but not with rCBF. By contrast, there was no significant difference in the rating scores or volumes of DWMHs between the two groups, although three patients had extensive DWMH lesions in the central white matter. In the group of patients with Alzheimer's disease as a whole, the volume of DWMHs correlated well with rCBF in the hippocampal region ( r = -0.72; p < 0.001), but not with frontal, temporal, parietal, or occipital rCBF. Postmortem histopathology of extensive DWMH lesions in one patient with definite Alzheimer's disease showed a partial loss of myelin and astrocytic gliosis, but no ischaemic changes. It is concluded that DWMH lesions may be associated with reduced rCBF in the hippocampal region. The heterogenous topography of neocortical rCBF deficits in Alzheimer's disease could not be explained by deafferentation from underlying white matter hyperintensities and therefore may reflect variations in the topography of cortical abnormalities.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Blood Flow Velocity; Blood Pressure; Case-Control Studies; Cerebral Ventricles; Cerebrovascular Circulation; Dementia; Female; Hippocampus; Humans; Magnetic Resonance Imaging; Male; Matched-Pair Analysis; Middle Aged; Organotechnetium Compounds; Oximes; Prospective Studies; Regional Blood Flow; Severity of Illness Index; Systole; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

A new method for the analysis of regional cerebral blood flow (rCBF) studies, the 'Min-Max' method, was compared with the conventional method, the 'Average' method. Regional CBF was examined by single photon emission computed tomography (SPECT) using 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO). The two methods were used to quantify the rCBF in a population of patients with various dementia disorders, and in healthy controls. Results from a phantom were also used. In the Average method the average counts per pixel (cp-1) within irregular manually drawn regions of interest (ROIs) was registered. In the Min-Max method the minimum cp-1 and maximum cp-1 within rectangular ROIs were registered for white and grey matter, respectively. The relative rCBF (rrCBF) was calculated as the ratio between the regional and cerebellar values. The Min-Max method gave systematically lower values for rrCBF in the white matter, in both clinical studies, and in the phantom, compared to the Average method. No difference was found in the grey matter results. The variability in rrCBF in the phantom study was greater with the Min-Max method than with the Average method, but this effect was counteracted in the clinical studies by a smaller interobserver error. The average regional differences between patients and controls appeared greater with the Min-Max method than with the Average method. The Min-Max method proved to be more simple to execute, involved a smaller observer error, and with respect to ability to distinguish patients with dementia disorders from controls, it appears to function at least as well as the accepted Average method.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Cerebrovascular Circulation; Dementia; Dementia, Multi-Infarct; Humans; Hydrocephalus, Normal Pressure; Middle Aged; Models, Structural; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Regional cerebral blood flow was studied using 99mTc-HM-PAO and single photon emission computed tomography (SPECT) in five healthy subjects and in eight patients with clinical and computed tomography (CT) features of subcortical arteriosclerotic encephalopathy. All the patients and controls underwent magnetic resonance imaging (MRI). Circumscribed cortical hypoperfusion was observed in three patients, and in one case there was no evidence of cortical or sulcal alterations on MRI. In all the patients, a reduction of the white matter perfusion was found in periventricular and/or supraventricular regions. This pattern was substantially correlated with the typical white matter hyperintensities shown by MRI scans. These findings support the hypothesis that white matter hypoperfusion is the most prominent functional abnormality in subcortical arteriosclerotic encephalopathy.

Topics: Aged; Brain; Cerebrovascular Circulation; Dementia; Demyelinating Diseases; Female; Humans; Intracranial Arteriosclerosis; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

It was reported from planar imaging studies that the cerebral uptake of injected 99mTc-HMPAO activity is about 4-7% in humans. Recent work has shown that modern SPECT/CT devices are able to quantify the tissue concentration of radioactivity in vivo in absolute units (Bq/ml), while avoiding the limitations of planar techniques. The aims of this study were (a) to determine the cerebral uptake of 99mTc-HMPAO in absolute units in SPECT/CT, (b) to investigate potential differences in absolute tracer uptake for patients suspected of dementia.. We performed 99mTc-HMPAO SPECT/CT in 65 patients with suspected dementia. 99mTc-HMPAO uptake was determined using a previously published quantitative SPECT/CT protocol. The absolute HMPAO uptake and the results of a regionalized analysis were compared for MMSE and NINCDS-ADRDA based patient groups.. The mean absolute uptake of 99mTc-HMPAO for our patient population was 4.3 ± 0.8% of the injected dose. The uptake, as well as the regionalized analysis yielded significantly different results for low (≤23) and high (>23) MMSE groups and also for some of the NINCDS-ADRDA groups.. Our results show that the absolute cerebral uptake of 99mTc-HMPAO is in the range of previously reported results, obtained by planar techniques. Absolute uptake is significantly different between the patient groups.

Topics: Aged; Aged, 80 and over; Brain; Computer Simulation; Dementia; Female; Humans; Image Interpretation, Computer-Assisted; Male; Metabolic Clearance Rate; Middle Aged; Models, Neurological; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Single Photon Emission Computed Tomography Computed Tomography; Technetium Tc 99m Exametazime

Patients with early-onset dementia (EOD) often present atypically, making an accurate diagnosis difficult. Single-photon emission-computed tomography (SPECT) provides an indirect measure of cerebral metabolic activity and can help to differentiate between dementia subtypes. This study aims to investigate the clinical utility of SPECT imaging in the diagnosis of early-onset Alzheimer's disease.. All patients attending a tertiary referral clinic specialising in EOD between April 2012 and October 2013 were included in the study. Statistical analysis of SPECT patterns with clinical diagnoses, Addenbrooke's Cognitive Examination version 3 scores, and magnetic resonance imaging (MRI) atrophy was undertaken.. The results demonstrated a highly significant association between SPECT hypoperfusion patterns and clinical diagnoses. SPECT changes were demonstrated more frequently than MRI atrophy.. The results suggest that SPECT imaging may be a useful adjunct to clinical evaluation and a more sensitive biomarker than standard structural imaging.

Topics: Aged; Alzheimer Disease; Atrophy; Brain; Cognition; Dementia; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Radiopharmaceuticals; Retrospective Studies; Technetium Tc 99m Exametazime; Tertiary Care Centers; Tomography, Emission-Computed, Single-Photon

To describe the clinical, positron emission tomography (PET), pathological, and genetic findings of a large kindred with progressive neurodegenerative phenotypes in which the proband had autopsy-confirmed corticobasal degeneration (CBD).. Five family members, including the proband, were examined neurologically. Clinical information from the other family members was collected by questionnaires. Three individuals underwent PET with (11)C-dihydrotetrabenazine and (18)F-fludeoxyglucose. The proband was examined post-mortem. Genetic studies were performed.. The pedigree contains 64 individuals, including 8 affected patients. The inheritance is likely autosomal dominant with reduced penetrance. The proband developed progressive speech and language difficulties at the age of 64 years. Upon examination at the age of 68 years, she showed non-fluent aphasia, word-finding difficulties, circumlocution, frontal release signs, and right-sided bradykinesia, rigidity, and pyramidal signs. She died 5 years after disease onset. The neuropathology was consistent with CBD, including many cortical and subcortical astrocytic plaques. Other family members had progressive neurodegenerative phenotypes - two were diagnosed with parkinsonism and behavioral problems, two with parkinsonism alone, one with amyotrophic lateral sclerosis alone, one with dementia, and one with progressive gait and speech problems. PET on three potentially affected individuals showed no significant pathology. Genetic sequencing of DNA from the proband excluded mutations in known neurodegenerative-related genes including MAPT, PGRN, LRRK2, and C9ORF72.. Families with such complex phenotypes rarely occur. They are usually associated with MAPT mutations; however, in this family, MAPT mutations have been excluded, implicating another causative gene or genes. Further genetic studies on this family may eventually disclose the etiology.

Topics: Aged; Aged, 80 and over; C9orf72 Protein; Dementia; Family Health; Female; Humans; Intercellular Signaling Peptides and Proteins; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Longitudinal Studies; Male; Middle Aged; Motor Neuron Disease; Mutation; Parkinsonian Disorders; Positron-Emission Tomography; Progranulins; Protein Serine-Threonine Kinases; Proteins; Psychiatric Status Rating Scales; Severity of Illness Index; tau Proteins; Technetium Tc 99m Exametazime; Tetrabenazine; Tomography, Emission-Computed, Single-Photon

The objective of this study was to examine the diagnostic accuracy of imaging and CSF biomarkers in clinically ambiguous dementia (CAD). 69 patients were prospectively followed. The endpoint was clinical diagnosis at follow-up of 24 months based upon existing criteria. Medial temporal lobe atrophy score on MRI, distinctive patterns on 99 mTc-HMPAO-SPECT, and CSF levels of amyloid-β peptide, total tau protein, and P-tau181P were used together with neuropsychological testing to assess Se (sensitivity) and Sp (specificity) of separate and combined markers. 60 patients reached the endpoint. A definite diagnosis was achieved in 48 patients. CSF biomarkers had a Sp of 71% and a Se of 100% for Alzheimer's disease (AD) diagnosis. Sp increased to 88% and 93% when MRI and MRI + SPECT were combined, at the expense of Se. CSF biomarkers levels also provided clues to frontotemporal (FTD) or vascular dementias (VaD) diagnosis when situated in an intermediate range between normal and pathological values. MRI and SPECT contributed mostly to the diagnosis of VaD (Se 88%, Sp 75%) and FTD (Se 73%, Sp 78%), respectively. Initial neuropsychological testing had a poor diagnostic accuracy, except for a neuropsychiatric inventory score >40 for the diagnosis of FTD (Se 73%, Sp 84%). Independent of the clinical diagnosis, medial temporal lobe atrophy and total-tau were best correlated with cognitive decline at 2 years. In conclusion, CSF biomarkers efficiently predict evolution toward an AD phenotype in CAD. Imaging biomarkers mostly contribute to the differential diagnosis between non-AD dementias. Initial neuropsychological testing was poorly contributive in CAD diagnosis.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Brain; Dementia; Diagnosis, Differential; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Prognosis; tau Proteins; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

(99m)Tc-exametazime single photon emission computed tomography (SPECT) scans of 36 patients with Alzheimer's disease (AD) and 30 with dementia with Lewy bodies (DLB) underwent region of interest (ROI) and principal component analysis (PCA). Principal component analysis was performed on the entire ROI data set. Principal components (PCs) were obtained, representing common intercorrelated regions in AD and DLB. Topographic expression that signified the extent to which a participant expressed the topographic covariance pattern was derived and used as a discriminatory variable. Principal components were identified, accounting for 77% of total data variance. Significant (PC x group) interaction was observed (P < .001). Topographic expression was significantly higher in DLB than AD (F(1,64) = 21.6, P < .001), and differentiated DLB from AD with sensitivity 73% specificity 72%. Calculating the topographic expression in an independent data set of 48 patients with AD and 23 with DLB gave sensitivity = 70%, specificity = 67%. Principal component analysis captures additional sources of variance and if perfusion SPECT is the only scan available, this procedure may offer extra information.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Analysis of Variance; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Female; Humans; Lewy Body Disease; Male; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Quantifying hemispheric cerebral blood flow (CBF) may improve diagnostic accuracy when combined with perfusion SPECT.. To explore the impact of measuring mean CBF on the differential diagnosis of dementia under clinical conditions.. CBF was calculated from anterior planar dynamic images acquired over 100 s after i.v. bolus injection of 550 MBq of (99m)Tc-HMPAO using Patlak linearization of normalized time-activity curves derived from right and left hemispheric, and aortic ROIs. Regional perfusion was evaluated from SPECT imaging carried out 20 min later. ANCOVA was applied to compare age-dependent differences of CBF; model differences at P<0.05 were considered significant. Study populations consisted of controls, 34 patients with no focal or vascular abnormality or mood disorder and with normal MR or CT brain images (F:M, 16:18; age+/-SD; 54.3+/-20.2 years); and patients with probable dementia comprised two subgroups. The first consisted of 33 patients with primary degenerative aetiology (PDD) (DAT or mixed-type microvascular and DAT, Lewy body and fronto-temporal atrophy), F/M; 17:16, age+/-SD; 68.4+/-8.8 years. The second subgroup consisted of 13 patients with dementia related to subcortical microvascular leuco-encephalopathy (vLEP), M/F 7:6, age+/-SD; 71.7+/-12.6 years. Classification was mainly based on clinical findings according to DMS-IV criteria, combined with follow-up or functional and anatomical imaging.. Computation of CBF on 100 consecutive patients showed excellent inter-user reproducibility in trained hands (variation coefficient <5%). Mean CBF in controls showed an age dependent decrease, the first order linear regression was CBF(left)=58.9-0.2 x age (r=-0.648, P<0.001) and CBF(right)=57.9-0.02 x age (r=-0.645). In comparison to controls, a slightly more pronounced but statistically insignificant age-dependent decrease in mCBF was found in the vLEP group, CBF(left)=55.5-0.21 x age (r=-0.56) and CBF(right)=64.2-0.32 x age (r=-0.645). In the PDD group CBF, after adjusting for age, was significantly lower than control values (P<0.001); CBF(left)=37-0.025 x age and CBF(right)=39-0.057 x age. More importantly, better discrimination between PDD and controls in patients of younger age (45-65 years) was found. In older patients (65-85 years) overlap slightly increased. ROC analysis of the cohort of dement patients and controls older than 46 years revealed a 93-94% sensitivity and a specificity of 73% and 77% for the left and right hemispheres, respectively, at a CBF cut-off value of 39.5 ml.min(-1).100 g(-1).. Routine quantification of mean CBF by HMPAO-RNA is a simple and reproducible method which can be easily added to the standard brain perfusion SPECT without additional cost or increasing patient's radiation burden. Combined with regional perfusion it provides an additional tool for the aetiological classification of dementia.

Topics: Aged; Brain; Cerebrovascular Circulation; Dementia; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the commonest causes of presenile dementia. In the absence of a biological marker, diagnosis is reliant on clinical evaluation. Confirmation is often sought from neuroimaging, including single-photon emission computed tomography (SPECT). Most previous SPECT studies lack pathological validation.. To examine the accuracy of SPECT in differentiating FTD from AD in patients with subsequent pathological confirmation.. Technetium-99-labelled hexamethyl propylene amine oxime SPECT images obtained at initial evaluation in 25 pathologically confirmed cases of FTD were examined. These images were visually rated by an experienced blinded nuclear medicine consultant and compared with those of 31 patients with AD, also with pathological validation.. A reduction in frontal cerebral blood flow (CBF) was more common in FTD and was of diagnostic value (sensitivity 0.8, specificity 0.65 and likelihood ratio (LR) 2.25; 95% CI 1.35 to 3.77). A pattern of bilateral frontal CBF reduction without the presence of associated bilateral parietal CBF change is diagnostically more accurate (sensitivity 0.80, specificity 0.81 and +LR 4.13, 95% CI 1.96 to 8.71). Diagnostic categorisation (FTD or AD) on the basis of SPECT alone was less accurate than clinical diagnosis (based on neurology and detailed neuropsychological evaluation). One patient with FTD was initially clinically misdiagnosed as AD, owing to the lack of availability of full neuropsychological assessment. However, SPECT correctly diagnosed this patient, providing a diagnostic gain of 4%.. Technetium-99-labelled hexamethyl propylene amine oxime SPECT CBF patterns provide valuable information in the diagnosis of FTD and AD. These data can be better used as an adjunct to clinical diagnosis if pathology is to be correctly predicted in life.

Topics: Aged; Alzheimer Disease; Brain; Dementia; Diagnosis, Differential; Female; Frontal Lobe; Humans; Male; Middle Aged; Radiopharmaceuticals; Regional Blood Flow; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The purpose of this study is to determine the value of Tc-99m HMPAO SPECT in the diagnosis of the dementias, with particular reference to Alzheimer disease.. Tc-99m HMPAO was used with a 3-camera scanner to produce 5 sets of sectional images of the brain. Diagnosis was made by a physician blinded to the clinical diagnosis. Results in 49 subjects were ultimately compared with neuropathologic study of the brain at autopsy.. Sensitivity = 86.7% (68.4-95.6%, 95% confidence interval [CI]), specificity = 89.5% (65.5-98.2% CI), positive predictive value = 92.9% (75.0-98.8% CI), negative predictive value = 81% (57.4-93.7% CI), accuracy = 87.8% (74.5-94.9% CI), likelihood ratio = 8.23% (7.09-9.57% CI).. Comparison is made with several other SPECT and PET series with histopathologic correlation. Brain blood flow SPECT is useful in the diagnosis and differential diagnosis of the dementias.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; False Negative Reactions; False Positive Reactions; Female; Humans; Male; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Alzheimer Disease; Blood Flow Velocity; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Female; Fractals; Humans; Imaging, Three-Dimensional; Male; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A retrospective audit of (99m)Tc-HMPAO SPECT scans was undertaken to assess the utility of brain perfusion imaging in a cohort of young cognitively impaired patients in whom diagnostic uncertainty remained after standard clinical and neuropsychological assessment and structural brain imaging. SPECT scans were assessed by five raters (two neurologists and three nuclear medicine specialists) on two occasions 6 months apart, first without any clinical data and second with brief pertinent clinical information. SPECT diagnoses were compared with criterion diagnoses subsequently established by the two neurologists with access to all clinical, neuropsychological and neuroimaging data. Despite reasonable intra- and interrater reliability, diagnostic accuracy ranged from 32 to 58%. SPECT scan normality or abnormality in blind and informed viewings gave respective sensitivities of 77 and 71%, specificities of 44 and 38%, positive predictive values of 88 and 87% and negative predictive values of 27 and 18%. Calculating pairwise disease group comparisons, likelihood ratios suggested some diagnostic gain in differentiating AD from 'not AD' and from FTD/focal syndromes. SPECT scanning was of little help in establishing diagnoses in this cohort of patients, a finding which supports the conclusion of the American Academy of Neurology evidence-based review that SPECT imaging cannot be recommended for either the initial or the differential diagnosis of suspected dementia because it has not demonstrated superiority to clinical criteria.

Topics: Adult; Aged; Dementia; Diagnosis, Differential; Female; Humans; Likelihood Functions; Male; Medical Audit; Middle Aged; Observer Variation; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The diagnostic potential of F-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (PET) and technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (SPET) in early detection and differential diagnosis of early dementia was evaluated including a comparison of metabolic and perfusion indices (PI).. Twenty-four patients with initial clinical suspicion of beginning dementia were examined, 12 of them with mild cognitive impairment. All patients underwent SPET and PET within 2 weeks. Data were compared with the final clinical diagnosis at follow-up - 9 with Alzheimer's disease (AD), 1 with frontotemporal dementia, 1 with vascular dementia (VD), 7 with mixed type of dementia (MIX) and 6 without any type of dementia. Metabolic indices (MI) and PI were compared with each other. The regional cerebral blood flow difference (rCBFdiff) calculated as local uptake difference between the right and left hemisphere was measured for patients with VD and MIX.. PET showed higher sensitivity and specificity in identifying the different types of early dementia (44--91 and 78--89%, respectively) than SPET (11--64 and 79--89%, respectively), especially in detecting AD (sensitivity 44%, specificity 83%) and MIX (sensitivity 71%, specificity 78%). Especially in patients with mild cognitive impairment, PET was the superior imaging modality for predicting dementia. Using PET, dementia could be excluded in all patients who did not develop dementia during the follow-up. In all patients, a weak correlation between PI and MI was observed (rho=0.64, p<0.002). The rCBFdiff in patients with VD and MIX ranged from 7 to 37%.. In this study on patients with initial suspicion of beginning dementia who underwent both imaging modalities, PET and SPET, PET was the superior imaging method, especially in the detection of early AD or MIX.

Topics: Aged; Brain; Brain Chemistry; Cerebrovascular Circulation; Cognition Disorders; Dementia; Female; Fluorodeoxyglucose F18; Glucose; Humans; Male; Neuropsychological Tests; Positron-Emission Tomography; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 58-year-old man presented with a history of disturbance in initiating gait. His history revealed meningoencephalitis five years prior to admission. Neurological examination included gait disturbance as difficulty in initiation and a hesitating speech with many freezing episodes and micrographia Magnetic resonance imaging (MRI) showed diffuse hyperintensity of frontal subcortical white matter on T2 weighted images. He was diagnosed with PA. L-Dopa up to the dosages of 1000 mg/ day and selegiline 10 mg/day were given. First brain SPECT using technetium-99m labeled D,L-hexamethylpropylene amine oxime (Tc-99m HMPAO) was performed when he was taking L-dopa and selegiline. In visual evaluation, hypoperfusion in bilateral frontoparietal cortex was seen (Fig. 2). Treatment with L-dopa and selegiline produced no benefit. Donepezil 10 mg/day was begun. This therapy regimen resulted in dramatic clinical improvement within several days that was confirmed by blinded raters who watched the patient's video recordings. During this response second brain perfusion SPECT study was repeated during donepezil therapy. Markedly increased perfusion in bilateral frontoparietal cortex was observed. This is the first case of PA to develop possibly after an episode of bacterial pneumococcal meningoencephalitis and who responded to donepezil as documented by changes in clinical findings and Tc-99m HMPAO brain SPECT studies.

Topics: Alexia, Pure; Brain; Cholinesterase Inhibitors; Dementia; Donepezil; Gait Disorders, Neurologic; Indans; Neurodegenerative Diseases; Piperidines; Radiopharmaceuticals; Recovery of Function; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

This was a study to evaluate the posterior cingulate sign in differential diagnosis between Alzheimer's and frontotemporal disease. The impending availability of effective treatment for Alzheimer's disease makes this differential diagnosis important.. Images of 20 patients with clinically confirmed or autopsy-proven (10 patients) Alzheimer's disease and 20 patients with clinically confirmed or autopsy-proven (7 patients) frontotemporal disease were compared with the consolidated images of 20 elderly healthy control subjects. The (99m)Tc-hexamethylpropyleneamine oxime SPECT data on brain blood flow from each patient were compared with the consolidated control image using statistical parametric mapping.. Sixteen of 20 patients with Alzheimer's disease showed the posterior cingulate sign in the form of significant blood flow reductions; 1 of 20 patients with frontotemporal disease showed the posterior cingulate sign. That patient's illness has evolved into Alzheimer's disease. The remaining 19 patients were negative for the posterior cingulate sign.. When present, the posterior cingulate sign indicates the presence of Alzheimer's disease; it is apparently absent in frontotemporal disease, thus serving as a differential diagnostic sign. It was absent in 3 patients with proven tangle-predominant Alzheimer's disease.

Topics: Aged; Alzheimer Disease; Brain; Case-Control Studies; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Frontal Lobe; Gyrus Cinguli; Humans; Predictive Value of Tests; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Lateralization on neuroimaging was compared in cases of frontotemporal lobar degeneration (FTLD; n = 10) and cases of definite Alzheimer's disease (AD; n = 17). All of the cases were pathologically confirmed and semi-quantitative and statistical parametric mapping methods were employed. Seven of the 10 FTLD cases had lateralization on at least one neuroimaging modality: single photon emission computerized tomography (SPECT), MRI, or CT. All 6/6 FTLD cases with SPECT showed lateralization. MRI results generally agreed with SPECT findings. Three of 4 FTLD cases had lateralized atrophy on CT. For the AD cases, 10/17 SPECTs, 2/7 MRIs, and 1/9 CTs showed lateralized findings. Of the neuroimaging modalities utilized, SPECT was the most sensitive in detecting lateralization.

Topics: Alzheimer Disease; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Dominance, Cerebral; Humans; Longitudinal Studies; Magnetic Resonance Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We investigated the impact of the quantitation and reconstruction protocol on clinical tasks. The performance of standard clinical reconstruction procedures in discrimination tasks related to the diagnosis of prodromal Alzheimer's disease (AD) was compared with the performance of a quantitative approach incorporating improved corrections for scatter, attenuation, intrinsic spatial resolution, and distance-dependent spatial resolution.. Seventeen normal controls (normal group), 56 subjects who did not have dementia, who did have memory problems, but who did not develop AD within 5 y of follow-up (questionable group), and 27 subjects who did not have dementia, who did have memory problems, and who did develop AD over the follow-up period (converter group) were considered in this study. (99m)Tc-hexamethylpropyleneamine oxime SPECT and MRI studies were performed for each subject at baseline. The standard quantitation protocol (STD), routinely used in our clinic, consisted of Compton window scatter correction followed by filtered backprojection with attenuation correction using a uniform attenuation map. In the improved quantitative approach (QUAN), projections were corrected for scatter by use of a general spectral method and reconstructed by use of ordered-subset(s) expectation maximization, incorporating corrections for collimator response and attenuation using both a uniform attenuation map (QUANunif) and a nonuniform attenuation map (QUANnonunif). Mean SPECT activity concentration and MRI volume were estimated for 7 structures: rostral anterior cingulate gyrus, caudal anterior cingulate gyrus, posterior cingulate gyrus, hippocampus, basal forebrain, amygdala, and the banks of the superior temporal sulcus. Data were analyzed by pairwise discriminant analysis, and performance in binary group discrimination was measured by correlated receiver-operating-characteristic analysis.. The use of QUANnonunif yielded a small but systematic improvement in discrimination accuracy for normal versus converter groups (accuracy or area under the receiver-operating-characteristic curve [Az], 0.965), normal versus questionable groups (Az, 0.973), and questionable versus converter groups (Az, 0.881) compared with the results obtained with QUANunif (Az, 0.955, 0.962, and 0.866, respectively). Discrimination performance was significantly lower (P < 0.05) with STD than with QUAN in all 3 tasks (Az with STD, 0.906, 0.878, and 0.768, respectively). MRI volume estimation led to a lower overall performance in all 3 tasks than did QUANnonunif (Az with MRI, 0.947, 0.917, and 0.872, respectively).. Improved quantitative image reconstruction with accurate compensation for scatter, attenuation, and variable collimator response led to significantly better performance in discrimination tasks related to the diagnosis of prodromal AD than did standard clinical reconstruction procedures. The use of a nonuniform brain attenuation map yields a small improvement in discrimination accuracy.

Topics: Aged; Alzheimer Disease; Brain; Dementia; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We investigated changes in the brain distribution of (-)-[(125)I]-m-iodovesamicol [(-)-[(125)I]mIV] in cholinergic denervation rats produced by a unilateral lesion of the nucleus basalis magnocellularis (NBM). Dual-tracer ex vivo autoradiographic analysis using (-)-[(125)I]mIV and [(99m)Tc]HMPAO was conducted to the effect of regional cerebral perfusion on the brain distribution of (-)-[(125)I]mIV in a unilateral NBM-lesioned rat. (-)-[(125)I]mIV binding in the ipsilateral cortex to the lesion significantly reduced by 10.4 %, compared with that in the contralateral cortex, while (-)-[(125)I]mIV binding in the ipsilateral caudate putamen, hippocampus and thalamus did not change. The rate of reduction in the (-)-[(125)I]mIV binding (10.4 %) was significantly higher than that of [(99m)Tc]HMPAO accumulation (4.0%) in the ipsilateral cortex to the lesion (P < 0.01). These results suggested that radioiodinated (-)-mIV may be useful in the study of dementia characterized by degeneration of the cholinergic neurotransmitter system, such as Alzheimer's disease.

Topics: Acetylcholine; Animals; Autoradiography; Brain; Dementia; Male; Piperidines; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Technetium Tc 99m Exametazime; Tissue Distribution

To compare the utility of temporal lobe magnetic resonance imaging (MRI) and single-photon emission tomography (SPET) scanning in discriminating between subjects with Alzheimer's disease (AD) and age-matched controls.. Thirty subjects with NINCDS-ADRDA AD (23 probable AD, 5 possible AD, 2 definite AD) and 22 age- and sex-matched controls underwent T1-weighted coronal MRI scanning (0.3 T) and technetium 99m-HMPAO SPET scanning. MRI scans were analyzed using a digitizer system with volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and whole cerebral cortex calculated. From SPET scans, regional cerebral blood flow (rCBF) was assessed in anterior and posterior frontal, parietal, occipital, and mesial temporal cortex using a region of interest analysis with the cerebellum as a reference area.. Using MRI, the areas that best separated groups were left hippocampal and left amygdala volume, resulting in correct classification (patient vs. control) in 79% of cases (sensitivity 77%, specificity 82%). Exactly the same proportion of subjects were correctly classified by SPET, with the most discriminating rCBF changes being left parietal and right posterior frontal. Combining information from both scans improved the proportion of correctly classified subjects in a discriminant function to 90% (sensitivity 93%, specificity 86%; only 2 AD and 3 controls misclassified). All AD subjects had abnormalities on MRI and/or SPET (sensitivity for combined examinations 100%), while abnormalities on both MRI and SPET had a positive predictive value of 100% for dementia (including the detection of one control subject who later had dementia). Significant correlations between MRI and SPET measures were seen in control subjects but not in patients.. Both 0.3 T MRI and single rotating gamma camera SPET were equally useful in separating AD subjects from age-matched controls, although the combination of both significantly enhanced discrimination. In particular, all AD subjects had abnormalities on either MRI or SPET and both techniques may have an important role in assisting with clinical diagnosis, though replication in other centers and examination of differentiation of AD from other causes of dementia need to be examined.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Brain; Case-Control Studies; Dementia; Diagnosis, Differential; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Predictive Value of Tests; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most frequent neurodegenerative cognitive disorders. However, FTD remains poorly recognised clinically. The use of (99m)HmPAO-single photon emission computed tomography (SPECT) has been demonstrated in the differentiation of AD and FTD. Nethertheless, there are very few comparative studies designed to assess its precise value in this differential diagnosis. The aim was to determine a simple decision rule, deduced from statistical analysis, which, if applied to regions of interest (ROIs) and mini mental state examination (MMSE), could improve the predictive value of SPECT in differential diagnosis between AD and FTD.. Forty patients, 20 with probable AD and 20 with probable FTD were included. All patients underwent brain SPECT imaging, after an intravenous injection of (99m)Tc HmPAO-(555mBq). For each patient, 20 ROIs were determined on the Fleishig's slice and their activity was normalised to the mean cerebellar activity. Bivariate analysis (Wilcoxon rank tests) and multivariate analysis (stepwise discriminant analysis) were performed to determine the subgroup of variables able to give the highest predictive value for this differential diagnosis. A simple decision rule was built from a predictive score derived by factorial discriminant analysis.. As previously described, the fixation defect was found in frontal regions of interest (ROIs) in FTD and in the left temporoparietal-occipital ROIs in AD. Among the 21 variables, five were finally selected: right median frontal, left lateral frontal, left tempoparietal, left temporoparietal-occipital areas, and MMSE. One hundred per cent of patients with FTD were correctly classified by the decision rule (20/20 patients) and 90% of patients with AD (18/20).. AD and FTD are differentiated by SPECT. Automatic classification based on a decision rule deduced from factorial discriminant analysis could enhance its performance.

Topics: Alzheimer Disease; Brain; Dementia; Discriminant Analysis; Frontal Lobe; Humans; Multivariate Analysis; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

To examine the role of structural (magnetic resonance imaging [MRI]) and functional (single photon emission computed tomography [SPECT]) imaging and neuropsychologic evaluation in the early diagnosis of frontal variant frontotemporal dementia (fvFTD).. Current criteria for FTD stress the need for neuropsychologic and functional neuroimaging abnormalities, yet caregivers report lengthy histories of behavioral change. It is not known when, in the course of the disease, these investigations become abnormal, because few longitudinal studies have been reported.. Longitudinal study of two patients with serial neuropsychologic evaluation and MRI and HMPAO-SPECT scanning.. Both patients, men aged 49 and 50, had major changes in personality, behavior, and social conduct that progressed over 5 to 6 years in a way that conformed to the clinical picture of fvFTD. There was remarkably little abnormality on neuropsychologic testing, and MRI and HMPAO-SPECT findings initially were normal. Over time, however, abnormalities on SPECT, frontal atrophy on MRI, or a neuropsychologic profile more typical of fvFTD developed in both patients.. Standard neuropsychologic tests and conventional brain imaging techniques (MRI and SPECT) may not be sensitive to the early changes in fvFTD that occur in the ventromedial frontal cortex, and better methods of accurate early detection are required. These findings are relevant to the diagnostic criteria for FTD.

Topics: Atrophy; Chronic Disease; Cognition Disorders; Dementia; Disease Progression; Frontal Lobe; Humans; Irritable Mood; Longitudinal Studies; Magnetic Resonance Imaging; Male; Memory Disorders; Middle Aged; Neuropsychological Tests; Personality Disorders; Sensitivity and Specificity; Social Behavior Disorders; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Brain; Cisterna Magna; Dementia; Female; Humans; Magnetic Resonance Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We report the history of a 38 year old patient who began to develop mental deterioration at the age of 26. After a time of 7 years neurological signs like writing dystonia occurred. Hallervorden-Spatz-Disease (HSD) was diagnosed at the age of 36 in vivo with the clinical presentation of severe dystonia, rigidity, dementia, and typical signal loss in the globus-pallidus the reticular part of the substantia nigra, and the nucleus ruber in the T-2 weighted MRI. The "eye-of-the-tiger"-sign, a bilateral hyperintensity in the rostral globus pallidus, was not observed in follow-up examinations. HSD is a rare autosomal-recessive or sporadic disease of unknown etiology. In one third of the patients a dementing process is the first clinical sign of the disorder, and is a rare differential diagnosis of early onset dementia.

Topics: Adult; Atrophy; Brain; Cognition Disorders; Dementia; Diagnosis, Differential; Disease Progression; Dystonia; Globus Pallidus; Humans; Magnetic Resonance Imaging; Male; Pantothenate Kinase-Associated Neurodegeneration; Red Nucleus; Substantia Nigra; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 69-year-old man had hypothyroid dementia as a result of I-131 therapy and an overdose of methimazole. Tc-99m HMPAO SPECT revealed diffuse cerebral hypoperfusion. The findings of brain SPECT normalized with the disappearance of symptoms and a return to the euthyroid state. There was a 25% or 26% reduction of the mean cerebral blood flow during dementia. This may be the first report in which SPECT brain imaging revealed reversible hypoperfusion associated with reversible hypothyroid dementia.

Topics: Aged; Antithyroid Agents; Brain; Cerebrovascular Circulation; Dementia; Graves Disease; Humans; Hypothyroidism; Iodine Radioisotopes; Male; Methimazole; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Thirty-four patients with a probable Alzheimer's Disease (AD) (mild AD = 16; moderate AD = 18) and 12 matched controls were evaluated using semiquantitative SPECT-99mTc-HMPAO and neuropsychological tests (CERAD).. Both temporal hypoperfusion (p < 0.01) and memory tests (p < 0.001) made it possible to differentiate the controls from mild AD patients. In these patients, significant correlations (p < 0.05) were also found between: 1) delayed recall test/temporal hypoperfusion, 2) learning memory test/temporoparietal and frontal hypoperfusion and 3) visual constructive praxis/posterior temporal hypoperfusion. In contrast to mild AD, moderate AD patients showed higher temporal (p < 0.01) parietal and frontal (p < 0.05) hypoperfusion along with worsening of praxis (p < 0.001) and memory tests (p < 0.05).. SPECT imaging and neuropsychology evaluation can distinguish controls from AD patients with mild an moderate grades of dementia, showing a strong correlation from the early stages of AD.

Topics: Aged; Alzheimer Disease; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Female; Humans; Male; Memory Disorders; Middle Aged; Neuropsychological Tests; Sensitivity and Specificity; Severity of Illness Index; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

To provide the clinician with a guide to the clinical utility of 99mTc-HMPAO single photon emission computed tomography (SPECT) and to the interpretation of specific test results in the differential diagnosis of dementia.. Three hundred and sixty three patients with dementia were studied prospectively for a median three (range 1-6) years and classified into disease groups on the basis of established clinical criteria. The degree to which different patterns of cerebral blood flow (CBF) abnormality found on 99mTc-HMPAO SPECT imaging at the time of initial patient presentation modified clinical diagnoses was determined by calculating the likelihood ratios for pairwise disease group comparisons. The optimal clinical usage of 99mTc-HMPAO SPECT was determined by calculating the percentage of significant test results for each pairwise disease group comparison.. Bilateral posterior CBF abnormality was found to significantly increase the odds of a patient having Alzheimer's disease as opposed to vascular dementia or frontotemporal dementia. Bilateral anterior CBF abnormality significantly increased the odds of a patient having frontotemporal dementia as opposed to Alzheimer's disease, vascular dementia, or Lewy body disease. "Patchy" CBF changes significantly increased the odds of a patient having vascular dementia as opposed to Alzheimer's disease. Unilateral anterior, unilateral anterior plus unilateral posterior, and generalised CBF abnormality failed to contribute to the differentiation of any of these forms of dementia.. 99mTc-HMPAO SPECT was found to be most useful in distinguishing Alzheimer's disease from vascular dementia and fronto temporal dementia, and least useful in differentiating between Alzheimer's disease and Lewy body disease, and between vascular dementia, frontotemporal dementia, and progressive aphasia. It is suggested that CBF SPECT should be used selectively and as an adjunct to clinical evaluation and CT.

Topics: Aged; Alzheimer Disease; Aphasia, Primary Progressive; Dementia; Dementia, Vascular; Diagnosis, Differential; Female; Humans; Likelihood Functions; Male; Middle Aged; Odds Ratio; Parkinson Disease; Prospective Studies; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Aged; Brain; Cerebrovascular Disorders; Child, Preschool; Cysteine; Dementia; Epilepsy; Humans; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

To evaluate single photon emission computed tomographic (SPECT) imaging of regional cerebral blood flow in the diagnosis of Alzheimer disease (AD) and the differential diagnosis of the dementias.. Regional cerebral blood flow SPECT was performed with inhaled xenon-133 in 261 patients and with injected technetium-99m hexamethyl-propyleneamine oxime (HMPAO) in 162 patients with possible dementia. In 16 patients, both agents were used in 1 day. SPECT images obtained in elderly healthy control subjects (with Xe-133 in 15, with Tc-99m HMPAO in 14) were available. In each patient without AD, further classification of disease was attempted. Histopathologic correlation was available in 54 patients (with autopsy in 51, with biopsy in three).. SPECT diagnoses were true-positive in 37, true-negative in eight, false-positive in three, and false-negative in six patients. Sensitivity was 86% (37 of 43; 95% confidence limits = .72, .95); specificity, 73% (eight of 11; confidence limits = .39, .94); positive predictive value, 92% (37 of 40; confidence limits = .80, .98); and negative predictive value, 57% (eight of 14; confidence limits = .29, .82).. Regional cerebral blood flow SPECT may assist in the early and late diagnoses of AD and in the differential-diagnosis of the dementias when there is a complicated or confusing clinical picture.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; False Negative Reactions; False Positive Reactions; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Research suggests an association between frontal and temporal injury and antisocial conduct. We studied the frequency of antisocial behaviours in fronto-temporal dementia (FTD) where pathology is anterior frontal-temporal, compared with Alzheimer's disease (AD) where pathology is primarily posterior temporal-parietal.. The presence of antisocial conduct was compared in 22 FTD versus 22 AD subjects. All FTD patients had anterior frontal or temporal hypoperfusion with single photon emission computed tomography, whereas those with AD had posterior temporal-parietal hypoperfusion.. Ten FTD and one AD subject showed antisocial behaviours, which included assault, indecent exposure, shoplifting and hit-and-run driving. Three FTD subjects were arrested. This difference was highly significant (P = 0.004).. Degeneration of frontal and temporal lobes predisposes to antisocial behaviour. This study supports a relationship between frontal-temporal dysfunction and certain types of antisocial activities.

Topics: Aggression; Alzheimer Disease; Antisocial Personality Disorder; Dementia; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Dementia of the Alzheimer-type (DAT) is characterized by progressive cognitive decline, variably combined with frontal lobe release signs, parkinsonian symptoms and myoclonus. The features of diffuse Lewy body disease (DLBD), the second most common cause of degenerative dementia, include progressive cognitive deterioration, often associated with levodopa-responsive parkinsonism, fluctuations of cognitive and motor functions, psychotic symptoms (visual and auditory hallucinations, depression), hypersensitivity to neuroleptics and orthostatic hypotension. A recent report suggests that positron emission tomography studies in patients with degenerative dementia may be useful in the differential diagnosis of DAT and DLBD. However, the diagnostic role of single-photon emission tomography (SPET) studies remains to be established. The aim of this study was therefore to evaluate regional cerebral perfusion [with either technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) or 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPET] and striatal dopamine transporter density [using iodine-123 2 beta-carboxymethoxy-3 beta-[4-iodophenyl]tropane (123I-beta-CIT) SPET] in patients with DAT and DLBD. Six patients with probable DAT and seven patients with probable DLBD were studied. Blinded qualitative assessment by four independent raters of 99mTc-HMPAO or 99mTc-ECD SPET studies revealed bilateral temporal and/or parietal hypoperfusion in all DAT patients. There was additional frontal hypoperfusion in two patients and occipital hypoperfusion in one patient. In the DLBD group, regional cerebral perfusion had a different pattern. In addition to temporoparietal hypoperfusion there was occipital hypoperfusion resembling a horseshoe defect in six of seven patients. In the DAT group, the mean 3-h striatal/cerebellar ratio of 123I-beta-CIT binding was 2.5 +/- 0.4, with an increase to 5.5 +/- 1.1 18 h after tracer injection. In comparison, in the DLBD patients the mean 3-h striatal/cerebellar ratio of 123I-beta-CIT binding was significantly reduced to 1.7 +/- 0.3, with a modest increase to 2.1 +/- 0.4 18 h after tracer injection (P < 0.05, Scheffe test, ANOVA). These results suggest that 99mTc-HMPAO or 99mTc-ECD and 123I-beta-CIT SPET may contribute to the differential diagnosis between DAT and DLBD, showing different perfusion patterns and more severe impairment of dopamine transporter function in DLBD than in DAT.

Topics: Aged; Alzheimer Disease; Brain; Carrier Proteins; Case-Control Studies; Cocaine; Cysteine; Dementia; Diagnosis, Differential; Dopamine; Dopamine Plasma Membrane Transport Proteins; Female; Humans; Iodine Radioisotopes; Male; Membrane Glycoproteins; Membrane Transport Proteins; Middle Aged; Nerve Tissue Proteins; Organotechnetium Compounds; Oximes; Parkinson Disease; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Dementia of the Alzheimer's type [(S)DAT] and dementia with frontal features (FLD) are nosological entities with different prognoses and presumed pathophysiology. There is a need for noninvasive differential diagnostic tools. To evaluate whether SPECT perfusion imaging could discriminate between these neurodegenerative disorders, we performed a comparative study.. SPECT scans using 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO) of 21 patients with FLD were compared with those obtained in a group of 19 age- and severity-matched patients suffering from (S)DAT. Brain SPECT perfusion deficits were scored by visual qualitative analysis with respect to location, lateralization and severity. A total severity score of cerebral hypoperfusion (maximal value = 18) was calculated by adding all severity scores (scored between 0 and 3; 0 = no perfusion deficit; 1 = 13%-30% hypoperfusion; 2 = 30%-50%, hypoperfusion and 3 = > 50% hypoperfusion including breaching of the cortex) for right and left frontal, parietal and temporal lobes. Moreover, bifrontal hypoperfusion (Fa) was scored, yielding a value between 0 and 6 by adding the two frontal severity scores.. No significant correlation was found between MMSE scores and total severity scores on SPECT. A statistically significant correlation was found between the Middelheim frontality score and frontal severity score. Statistically more significant bilateral hypoperfusion of the parietal lobes was found in the (S)DAT group. Conversely, bifrontal hypoperfusion was found more in the FLD group. Stepwise logistic regression analysis identified the severity of bifrontal hypoperfusion as the most significant contributing parameter to correctly classifying (S)DAT versus FLD on SPECT. The probability of predicting (S)DAT based on the SPECT scan is calculated with the following formula: [equation: see text] Using this equation, a value above 0.5 was predictive for (S)DAT and a calculated value under 0.5 was predictive for FLD. Using this model, 81% of the FLD group and 74% of the (S)DAT were correctly classified.. Technetium-99m-HMPAO SPECT may help in discriminating FLD from (S)DAT. Bifrontal hypoperfusion was found to be the most powerful predictor of clinical classification. Further validation of the presented logistic regression model is warranted.

Topics: Aged; Alzheimer Disease; Brain; Cerebrovascular Circulation; Dementia; Diagnosis, Differential; Female; Humans; Logistic Models; Male; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Twenty-six people with Down's syndrome (DS) were investigated using 99Tc(m)-hexamethylpropylene amine oxime (99Tc(m)-HMPAO) and single photon emission tomography (SPET). Dementia was diagnosed using a structured carer interview giving a deterioration score and by studying the case notes. Five subjects were clinically demented, 7 showed mild deterioration and 14 no deterioration. Increased deterioration correlated with advancing age (correlation coefficient 0.5425; P<0.02), but there was no significant difference between older (>40 years) and younger (<40 years) patients. Only one of the subjects with dementia had a regional cerebral blood flow (rCBF) abnormality that was of the dementia of Alzheimer type. Three subjects with mild deterioration and three with no deterioration had abnormal SPET scans. There was no association between the SPET abnormality and clinical dementia or with evidence of deterioration.

Topics: Adult; Age Factors; Brain; Dementia; Down Syndrome; Female; Humans; Intellectual Disability; Male; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Alzheimer's disease is the most frequent cause of degenerative dementia. Despite the available diagnostic criteria, improvement of diagnosic accuracy is still required. The aim of this prospective study was to assess in a large population of patients referred to a memory clinic the diagnostic value of the combination of medial temporal lobe atrophy on temporal oriented CT and decreased temporoparietal uptake on HMPAO single photon emission tomography (SPECT).. The study was conducted in 125 patients aged 51-93: 64 with probable Alzheimer's disease (Mean (SD) mini mental state examination (MMSE)=18.34 (6.93)), duration of disease=6.48 (2.93) years, 13 possible Alzheimer's disease (MMSE=21.58 (5.48), duration of disease=6.08 (2.56)), 48 patients with miscellaneous memory disorders (MMSE=21.98 (6.10), duration the disease = 6.85 (3.91)).. For the diagnosis of probable Alzheimer's disease, the sensitivity of this association was 0.56, the specificity 0.93, the positive predictive value 0.95, and the negative predictive value 0.45. The diagnosic accuracy was 0.68. Both medial temporal atrophy and parietotemporal decrease in uptake were present in four of 13 patients with possible Alzheimer's disease and 11 of 48 with miscellaneous memory disorders. The association was absent in 27 of 29 patients with frontotemporal dementia. In mild stages (MMSE>18; n = 32), the sensitivity of the association was 0.34, the specificity 0.93, the positive predictive value 0.85, and the negative predictive value 0.57. The diagnosic accuracy was 0.53.. This association, although not sensitive, helps to select patients with high probability of Alzheimer's disease at an early stage which can be of interest for clinical and research purposes.

Topics: Aged; Alzheimer Disease; Atrophy; Cognition Disorders; Dementia; Female; Frontal Lobe; Humans; Male; Neuropsychological Tests; Parietal Lobe; Predictive Value of Tests; Retrospective Studies; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

In a prospective study of more than 200 cases of dementia and 119 controls, annual technetium-99m-hexamethyl-propylene amineoxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) and annual medial temporal lobe (MTL) oriented X-ray computed tomography (CT) have been used to evaluate the diagnostic potential of functional and structural neuroimaging in the differential diagnosis of dementia. Some subjects have had up to 7 annual evaluations. So far, of 151 who have died, 143 (95%) have come to necropsy. Histology is known for 118, of whom 80 had Alzheimer's disease (AD), 24 had other "non-AD" dementias, and 14 controls with no cognitive deficit in life also had no significant central nervous system pathology. To compare the findings in the dementias with the profile of structural and functional imaging in the cognitively normal elderly, scan data from 105 living, elderly controls without cognitive deficit have also been included in the analysis. All clinical diagnoses were according to National Institute of Neurological and Communicable Disease and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; DSM-III-R) criteria, and all histopathological diagnoses according to the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria. Early data from this cohort have suggested that the combination of both MTL atrophy seen on CT with parietotemporal hypoperfusion on SPECT may predict the pathology of AD. The diagnostic sensitivity, specificity, accuracy, and positive and negative predictive values of the NINCDS-ADRDA and DSM-III-R criteria could be assessed in this cohort against the gold standard of histopathology. The diagnostic potential of CT evidence of MTL atrophy alone, SPECT evidence of parietotemporal hypoperfusion alone, and the combination of both of these scan changes in the same individual could then be compared against the diagnostic accuracy of clinical operational criteria in the pathologically confirmed cases. Furthermore, all of these modalities could be compared with the diagnostic accuracy of apolipoprotein E4 (Apo E4) genotyping to predict AD in the histopathologically confirmed cohort. In this population, NINCDS "probable-AD" was 100% specific, 49% sensitive, and 66% accurate; "possible-AD" was only 61% specific, but 93% sensitive and 77% accurate; and the combination of both "probable-AD" and "possible-AD"

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Apolipoproteins E; Atrophy; Cognition Disorders; Dementia; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Parietal Lobe; Predictive Value of Tests; Psychiatric Status Rating Scales; Radiopharmaceuticals; Severity of Illness Index; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

A semi-automatic method was developed to determine the anterior (AC) and posterior (PC) commissures on brain single-photon emission tomographic (SPET) perfusion images, and then to draw the proportional anatomical Talairach's grid on each axial SPET image. First, the AC-PC line was defined on SPET images from the linear regression of four internal landmarks (frontal pole of the brain, inferior limit of the anterior corpus callosum, sub-thalamic point and occipital pole). Second, the SPET position of AC and PC points on the AC-PC line was automatically determined from measurements made on hard copies of magnetic resonance (MR) images of the patients. Finally, a proportional Talairach's grid was automatically drawn on each axial SPET image. To assess the accuracy of localization of AC and PC points, co-registered technetium-99m hexamethylpropylene amine oxime SPET and MR images from 11 subjects were used. The mean displacements between estimated points on SPET and true points on MRI (Deltax=sagittal, Deltay=frontal and Deltaz=axial displacement) were calculated. The mean displacements (in mm) were Deltax=-1.4+/-1.8, Deltay=-1.7+/-3.3 and Deltaz=-1. 1+/-2.5 for AC, and Deltax=-1.8+/-1.8, Deltay=0.3+/-3.2 and Deltaz=-1.3+/-2.7 for PC. These displacements represented an error of less than 5 mm at the anterior or posterior pole of the brain or at the vertex. Intra- and inter-observer comparisons did not reveal significant differences in mean displacements. Thus, this semi-automatic method results in reproducible and accurate stereotactic localization of SPET perfusion abnormalities. This method can be used routinely for repeat follow-up studies in the same subject as well as in different individuals without requiring SPET-MRI co-registration.

Topics: Algorithms; Aphasia; Brain; Dementia; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Middle Aged; Observer Variation; Organotechnetium Compounds; Oximes; Reproducibility of Results; Stereotaxic Techniques; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 33-year-old, female presenting with dementia was admitted to our institution. Except for slight muscle atrophy noted on both lower extremities there were no other significant physical signs or laboratory findings. Since initial Tc-99m HMPAO SPECT showed hypoperfusion on both temporal, parietal and occipital lobes, follow up study with the same radiotracer was done. Increase in uptake was noted in the left side of the face. There was no abnormality noted on ENT examination. CT scan and MRI showed slight nasal mucosal wall thickening. T1-201 SPECT showed increased uptake in the nasal area. The increase in uptake could be due to nasal mucosal thickening. This could simulate nasal tumor and interfere in determining ROI for brain perfusion studies.

Topics: Adult; Brain; Dementia; Diagnosis, Differential; Diagnostic Errors; Female; Humans; Magnetic Resonance Imaging; Nasal Mucosa; Nose Neoplasms; Occipital Lobe; Organotechnetium Compounds; Oximes; Parietal Lobe; Spinocerebellar Degenerations; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

This study examines relations between regional cerebral blood flow (rCBF) and neuropsychological test results, age at onset and duration of disease in patients with frontotemporal-type dementia (FTD).. Sixteen patients with a diagnosis of probable FTD were examined using single photon emission computerised tomography (SPECT) with 99mTc-HMPAO as the tracer. The rCBF of 14 regions of interest relative to cerebellar blood flow was calculated. Psychological tests assessing language, verbal fluency, memory and visuospatial constructive ability were given.. Correlations were demonstrated between a global impairment score and relative blood flow in lateral frontal, medial frontal and left orbital frontal areas. Verbal fluency scores correlated with left lateral frontal, medial frontal and left anterior inferior temporal blood flow. No relationships between decrease in CBF and age at onset or duration of disease, or between impaired cognitive function and age at onset or duration of disease were found.. The present study demonstrates a close coupling between reduced rCBF and specific neuropsychological deficits in FTD.

Topics: Aged; Blood Flow Velocity; Brain Mapping; Dementia; Dominance, Cerebral; Female; Frontal Lobe; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The potential clinical utility of SPECT (Single Photon Emission Computed Tomography) brain imaging to clarifying certain diagnostic dilemmas faced by clinical psychiatrists is considered generally and is illustrated by several case vignettes. Three case histories consider dementia vs depressive pseudodementia, two the possibility of a cerebral vasculitis in patients with auto-immune conditions, and two whether the patient had a "type" of depression likely to benefit from a course of ECT. Published studies reviewing the utility of SPECT in dementia, depression, depressive "pseudodementia" and cerebral lupus are considered. It is suggested that SPECT is an important investigatory technique providing additional information that may assist some diagnostic decisions, while its utility in assisting other clinical decisions awaits clarification.

Topics: Adult; Aged; Brain; Brain Diseases; Dementia; Depressive Disorder; Diagnosis, Differential; Electroconvulsive Therapy; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

It is quite difficult to confirm the diagnosis of demential disorders, including senile dementia of the Alzheimer type (SDAT) by clinical means only. Through the combination of 99mTc-HMPAO brain SPECT and serum vitamin B12 determination it was hoped to speed up and improve the diagnosis of SDAT. 116 patients who had been divided into four groups according to their defect pattern in the 99mTc-HMPAO brain SPECT 17 very probably had SDAT; of these 15 showed a defect-pattern with brain SPECT which could be associated to SDAT. The majority of SDAT patients had serum vitamin B12 levels in the lower normal range or pathologically below that range. Both investigations contributed to establishing the SDAT diagnosis without replacing other investigations. The determination of serum vitamin B12 does not require any major additional effort.

Topics: Aged; Alzheimer Disease; Brain; Cerebral Infarction; Dementia; Diagnosis, Differential; Humans; Organotechnetium Compounds; Oximes; Reference Values; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Vitamin B 12

Dementia of the frontal type (DFT) is a degenerative disorder with early behavioral and language disturbances and with relative preservation of memory and visuospatial abilities. On neuropathology, DFT lacks the pathologic hallmarks of Alzheimer's disease (AD). We assessed the neuropsychological and SPET imaging features of 11 DFT and 16 AD patients. The two groups had similar performances on verbal learning, while the former had significantly higher nonverbal learning scores. Testing of verbal and nonverbal instrumental abilities showed that this different behavior could be due to poorer verbal fluency of DFT patients, and not necessarily to poorer learning. Neuropsychological data indicated that the often reported sparing of memory in daily functions of DFT patients can also be shown with formal neuropsychological testing of nonverbal learning. SPET showed a comparatively higher perfusion deficit of frontal regions in the left hemisphere of DFT patients, suggesting that this region might be affected more often in the disease.

Topics: Aged; Dementia; Female; Frontal Lobe; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Psychiatric Status Rating Scales; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Dementia in parkinsonian patients is estimated to 10-40%. Several factors may take part in the development of cognitive impairment: i/ defective function of subcortico-cortical pathways including the mesocorticolimbic dopamine deficiency with cell loss in medial substantia nigra, the degeneration of noradrenergic, serotonergic and cholinergic systems ii/ cortical and limbic Alzheimer pathology iii/ cortical Lewy bodies iv/ vascular alterations. Using HMPAO SPECT we distinguished three main types of hypoperfusion in Parkinson patients with dementia: i/ predominantly frontal lobe type ii/ posterior ("Alzheimer-like") type iii/ multiple small vascular defects. Neuropsychological investigation was based on the use of MMSE, word pair, digit span, verbal fluency, Lurija's tapping tests. In addition CURS and Hachinski's score were also applied. Selegiline (JumexR) therapy was introduced and the patients were followed for at least 60 days. Selegiline improved significantly the MMSE values and verbal fluency in the "frontal lobe" type further the memory functions in "Alzheimer-like" patients. The mechanism is still not clarified, the increased dopaminergic tone should be taken into account.

Topics: Antiparkinson Agents; Brain; Chronic Disease; Dementia; Dopamine; Humans; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Parkinson Disease; Selegiline; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Fifteen nondemented subjects with memory complaints underwent serial single photon emission computed tomography (SPECT) studies with technetium-99m-d, l-hexamethyl-propylene amine oxime (HMPAO) as tracer. Scans were carried out under a baseline conditions and during the learning phase of the Memory Efficiency Profile (MEP), a combined visual perception and memory task developed by Rey. Results indicate a positive correlation between activation, as indexed by HMPAO uptake, and neuropsychological assessment. Right temporal activation was correlated with MEP immediate recall. The right cerebellum was correlated with both MEP immediate and delayed recall. This study suggests that SPECT can show cortical activation during cognitive performance in subjects with mild memory impairment.

Topics: Aged; Aged, 80 and over; Amnesia; Arousal; Brain; Dementia; Female; Humans; Male; Mental Recall; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Pattern Recognition, Visual; Regional Blood Flow; Retention, Psychology; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Fifteen patients who had bilateral mediofrontal hypoactivity and 30 control subjects without this SPECT anomaly underwent Tc-99m HMPAO brain SPECT imaging. Bilateral mediofrontal hypoactivity was found in various neurologic disorders, including subcortical arteriosclerotic encephalopathy, lacunar state, chronic alcoholism, progressive nonvascular dementia, carbon monoxide poisoning, and diabetes mellitus. This SPECT abnormality was, however, specifically associated with three clinical signs: motor disabilities predominating in the lower limbs, urinary incontinence, and akinetic mutism.

Topics: Akinetic Mutism; Alcoholism; Cerebrovascular Circulation; Cerebrovascular Disorders; Dementia; Female; Frontal Lobe; Humans; Male; Middle Aged; Motor Skills; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Urinary Incontinence

Stringent quality control cannot be overemphasized in performing SPECT. SPECT artifacts related to camera uniformity, center of rotation, and the patient's motion are well recognized. In this communication, another rare cause of a SPECT artifact related to a triad system is reported. A triple-headed SPECT system was accidentally equipped with two ultrahigh-resolution collimators and a general all-purpose collimator during a brain SPECT study, causing a false cerebral blood flow defect.

Topics: Aged; Artifacts; Brain; Cerebellum; Cerebrovascular Circulation; Dementia; Female; Frontal Lobe; Humans; Image Processing, Computer-Assisted; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

This study evaluated the effect of using two different reference regions in the quantification of single-photon emission tomography (SPET). SPET scans of 30 patients with Alzheimer's disease (AD) and 30 patients with frontotemporal dementia were compared with the scans of ten age-matched controls. Regions of interest (ROIs) were defined on transaxial slices by a semi-automatic method. Regional cerebral blood flow indices (rCBFi) in each ROI were determined by normalizing the count densities to both cerebellar and occipital cortex reference regions. Mean rCBFi for each ROI were calculated for the patient and control groups and significant group differences determined. The number and topographical distribution of ROIs with significant group differences varied depending upon the choice of reference region. The magnitude of these differences was greatest when the cerebellum was used as the reference region. The disparity between results obtained with the two reference regions was most apparent in the AD group. The reasons for these differences are discussed and we conclude that the cerebellum is the more appropriate choice of reference region in the quantification of SPET in primary degenerative dementia.

Topics: Alzheimer Disease; Brain; Cerebellum; Cerebrovascular Circulation; Dementia; Female; Frontal Lobe; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

99mTc-HM-PAO single photon emission computed tomography (SPECT) was used to image 30 patients referred for the assessment of dementia. SPECT images revealed various patterns of regional cerebral perfusion (rCBF) in the subgroups of patients with the clinical diagnoses of Alzheimer's disease (AD, n = 14), Pick's disease (n = 1), and multi-infarct dementia (n = 7). In three patients, SPECT clarified the clinical differential diagnostic possibilities. Using a relative rCBF quantification technique, the relationship between specific cognitive impairments and rCBF in the AD patients was determined. There was a significant correlation between language impairment and left hemisphere hypoperfusion, whereas, apraxia correlated with hypoperfusion in the left parietal region. Thus, HM-PAO SPECT is useful as an aid in the differential diagnosis of dementia and the technique of relative rCBF quantification with SPECT may contribute to the understanding of the clinico-anatomical relations of cognitive deficits in dementia.

Topics: Aged; Alzheimer Disease; Brain; Cerebrovascular Circulation; Cognition Disorders; Dementia; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The uptake, at rest, of 99mTc-exametazime into different brain regions was compared using SPECT for 20 elderly subjects with major depressive disorder, 20 with Alzheimer-type dementia, and 30 age-matched normal volunteers. Uptake was referred to calcarine-occipital cortex as a reference sensory area. Cross-sectional differences between the three groups were highly statistically significant, but reflected primarily the reductions in cortical uptake in the Alzheimer group. A detailed comparison of depressed patients and controls identified decrements in anterior cingulate, temporal and frontal cortex and in caudate and thalamus in men only. These decrements were correlated with impairment of performance on a trail-making task, but were also associated with continuing treatment with antidepressants or benzodiazepines. However, most depressed patients had quantitatively normal scans for posterior parietal association cortex, and this suggests that SPECT may find a limited role in the differential diagnosis of depression and dementia. The reduced brain function in some depressed patients may parallel the findings from studies of brain structure in elderly depressives; there was between good outcome at 6-18 months and increased tracer uptake in subcortical areas.

Topics: Age of Onset; Aged; Aged, 80 and over; Alzheimer Disease; Analysis of Variance; Brain; Cognition Disorders; Dementia; Depressive Disorder; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Sex Factors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The sensitivity and specificity of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single-headed single photon emission computed tomography (SPECT) in dementia were evaluated in elderly patients with a mean age of 84 years suffering from dementia (n = 59) and compared to an age- and sex-matched control group with normal cognitive function (n = 14). The demented patients were classified as suffering from primary degenerative dementia (PDD, n = 51) based on DSM-III-R criteria. Moreover, PDD patients were divided into three subgroups of severity of cognitive impairment, according to their Folstein score. Multi-infarct dementia (MID, n = 8) was diagnosed based on clinical features, computed tomographic findings and Hachinski ischaemic score. Images were assessed qualitatively by visual interpretation of shades of colour in cortical regions. A SPECT defect confined to the frontal, parietal, temporal or (parieto) occipital lobe was defined as one lesion. The mean number of SPECT lesions was 1.4 (range 0-4) in the control group, 2.4 (range 0-8) in the PDD group and 2.9 (range 2-5) in the MID group and showed a significant difference (P < 0.02) between groups. To obtain an acceptable level of specificity of 64.3%, a cut-off value of three lesions had to be chosen. In the PDD group, sensitivity was then 25% for the mildly, 43.8% for the moderately and 46.7% for the severely affected PDD subgroup. In the MID group sensitivity was then 75%. Interestingly, in this elderly patient population the location of lesions was homogenously distributed in all groups, including the control group.

Topics: Aged; Aged, 80 and over; Dementia; Dementia, Multi-Infarct; Female; Humans; Male; Organotechnetium Compounds; Oximes; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tc-99m HMPAO, a lipophilic radiopharmaceutical used for brain imaging, has been reported to localize in smokers' lungs. To quantitate this uptake in the lung, 55 patients, who were referred for brain imaging for dementias or strokes, also underwent lung imaging (anterior lung imaging includes a large part of the liver) after IV injection of the radiopharmaceutical. Regions of interest over the liver and the lung were calculated. Of the 55 patients (ages 13-79), 30 were smokers and 25 were nonsmokers. The smokers had been smoking from 6-59 years, and daily cigarette consumption ranged from 8-50 cigarettes. The mean lung/liver ratio for smoking patients were 0.792 +/- 0.042 (SE); the mean lung/liver ratio for nonsmoking patients was 0.408 +/- 0.019 (SE). Lung/liver ratio uptake was significantly higher in the smoking patients (P < 0.01) than in the nonsmokers. Thus, lung/liver uptake of Tc-99m HMPAO may be used as an indicator of cigarette smoking.

Topics: Adolescent; Adult; Aged; Brain; Cerebrovascular Disorders; Dementia; Female; Humans; Liver; Lung; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Smoking; Technetium Tc 99m Exametazime

Topics: Alzheimer Disease; Brain; Cerebral Aqueduct; Dementia; Diagnosis, Differential; Female; Humans; Hydrocephalus; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Regional cerebral blood flow was assessed in 19 patients with early idiopathic Parkinson's disease (PD) and 12 control subjects of similar age by single-photon emission tomography using technetium-99m hexamethylpropylene amine oxime (HMPAO). Of the patients with PD, seven were mildly demented and 15 presented with hemiparkinsonism. Mean HMPAO cortical or basal ganglia/cerebellum activity ratios were calculated. Mean cortical and regional uptake ratios in non-demented PD patients were not significantly different from values in the controls. In contrast, besides generalized cortical hypoperfusion, demented PD patients had significantly lower HMPAO uptake in the frontal and basal ganglia regions than non-demented patients. These observations support the hypothesis of impaired neuronal activity in both cortical and subcortical regions of the brain in demented PD patients. In hemiparkinsonian patients, the only asymmetrical finding was a relative hypoperfusion in the contralateral parietal region. This may be due to deafferentation of the thalamoparietal pathways. The lack of asymmetrical uptake in basal ganglia in our PD patients may be explained by their staging at the time of the investigation (stage I and II, Hoehn and Yahr scale).

Topics: Aged; Brain; Dementia; Female; Humans; Male; Organotechnetium Compounds; Oximes; Parkinson Disease; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

For the purpose of facilitating anatomical localization in interpretation of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission tomographic (SPECT) scans, a stereotaxic proportional grid system was applied in the form of an interactive computer program. This method takes advantage of a rotating gamma camera system which permits planar scout imaging for the determination of anatomical reference lines, and standardization of tomographic slices for brain size. Using measurements made on a lateral planar HMPAO image, proportional grids were constructed onto standardized transaxial images. This method was implemented for 33 clinical HMPAO SPECT studies. It required less than 15 min of an operator's time. This simple and practical neuroanatomical localization technique can be instrumental as an aid to the interpretation of routine clinical HMPAO SPECT images.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Brain; Brain Diseases; Brain Injuries; Dementia; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Software; Stereotaxic Techniques; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) of brain was performed in 43 unselected patients with Parkinson's disease to evaluate whether low cerebral perfusion on SPECT correlated with cognitive impairment in the patients. All patients received neurological, Mini-Mental State Examination and a neuropsychological assessment. Eighteen (41.9%) of the 43 patients were demented. Thirty patients (69.8%) had abnormal SPECT: 17 had perfusion defects in cortical regions, eight in basal ganglia and five in both regions. Of the 22 patients with abnormal cortical perfusion, 15 (68.2%) were demented; only three (14.3%) of the 21 patients without cortical defect were demented (P < 0.01). Twelve of the 15 demented patients had low perfusion in the parietal region alone or in parietal and occipital regions. The cortical perfusion defects, present in 22 (51.2%) Parkinson's patients, are highly correlated with cognitive impairment. The pattern of SPECT abnormality in most demented patients with Parkinson's disease is similar to that seen in Alzheimer's disease, suggesting that the underlying pathophysiology for dementia in patients with Parkinson's disease may be similar to that in Alzheimer's disease.

Topics: Adult; Aged; Cerebrovascular Circulation; Cognition Disorders; Dementia; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Parkinson Disease; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The clinical, neuropsychological, and cerebral blood flow characteristics of eight patients with frontal lobe degeneration (FLD) were studied. Social withdrawal and behavioral disinhibition were the earliest and most common clinical presentations, and psychiatric symptoms typically preceded the onset of dementia by several years. Neuropsychological testing showed selective impairment of frontal and memory tasks with relative sparing of attention, language, and visuospatial skills. Single-photon emission computerized tomography demonstrated frontal and temporal hypoperfusion with relative sparing of parietal and occipital blood flow. Previous studies suggest that the neuropathologic findings in patients with FLD are varied; some demonstrate frontal gliosis, neuronal loss, and Pick bodies while others show only gliosis and neuronal loss.

Topics: Aged; Brain Diseases; Cerebrovascular Circulation; Dementia; Female; Frontal Lobe; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Tc-99m HMPAO, a lipophilic radiotracer used as a brain SPECT imaging agent in the diagnosis of strokes and dementias, is normally localized in the brain and the heart and is excreted through the kidneys (50%) and the hepatobiliary system (14% to 30%). There is no pulmonary localization except in the lungs of smokers. To evaluate pulmonary localization of Tc-99m HMPAO in relation to smoking, 23 patients (aged 27 to 76 years) who were referred for brain imaging studies for strokes or dementias also underwent lung imaging studies immediately following the brain imaging. Anterior and/or posterior lung images were obtained 30 to 45 minutes after IV injection of 15 mCi Tc-99m HMPAO. Diffuse pulmonary uptake was graded semiquantitatively: 3+, pulmonary uptake is equal to or higher than hepatic uptake; 2+, pulmonary uptake is less than hepatic uptake but higher than cardiac uptake; 1+, pulmonary uptake is equal to cardiac uptake; 0, pulmonary uptake is less than cardiac uptake. Each patient's smoking history, including duration and daily consumption, was recorded. Four patients' lung images showed 3+ lung uptake; 6 patients, 2+; 1 patient, 1+; and 12 patients, 0 uptake. Eleven patients with lung uptakes of 3+ to 1+ had a history of cigarette smoking. Twelve patients with lung uptake less than cardiac uptake had no smoking history. Pulmonary distribution of Tc-99m HMPAO is usually negligible in the normal lung. Our results indicate that lung uptake correlates significantly (chi-square = 23, d.f. = 1, P = 0.0001) with smoking history.

Topics: Adult; Aged; Brain; Cerebrovascular Disorders; Dementia; Humans; Lung; Male; Organotechnetium Compounds; Oximes; Smoking; Technetium Tc 99m Exametazime; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

To evaluate the usefulness of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) in suspected dementia we studied 160 consecutively imaged elderly patients from our hospital's memory disorder clinic. The diagnosis was based on clinical data, laboratory tests, neuropsychological examination, computed tomography (CT) and EEG. The patients were divided into six diagnostic categories: Alzheimer's disease (AD), multi-infarct dementia (MID), frontal lobe-type dementia (FTD), vascular encephalopathy not fulfilling the criteria of dementia, specific organic conditions, and psychiatric disorders. SPECT images were assessed without knowing the clinical diagnosis, and divided into AD pattern, FTD pattern, MID pattern, abnormal but unclassifiable, and normal. Twenty-three of 36 patients with clinical AD, 25/33 patients with clinical MID, and 2/5 patients with clinical TFD had compatible SPECT patterns. SPECT distinguished AD from MID in the majority (80%) of cases. In patients with depression or anxiety SPECT was abnormal in 16/21 cases, suggesting that SPECT may give early clues to the presence of an underlying organic disease in such elderly patients. Thus, SPECT with 99Tcm-HMPAO seems to be useful in the diagnosis of suspected dementia.

Topics: Aged; Alzheimer Disease; Cerebrovascular Circulation; Dementia; Dementia, Multi-Infarct; Diagnosis, Differential; Evaluation Studies as Topic; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Regional cerebral perfusion was evaluated by single photon emission computed tomography (SPET) using technetium 99m hexamethylpropylene amine oxime (99mTc-HMPAO) as a tracer, in 13 control subjects and 44 age-matched patients suffering from dementia of the Alzheimer's type (DAT, n = 19), presumed Pick's disease (n = 5), idiopathic Parkinson's disease with dementia (DPD, n = 15) and progressive supranuclear palsy (PSP, n = 5). HMPAO uptake was measured in the superior frontal, inferior frontal, parietal, temporal and occipital cortices, and the perfusion values were expressed as cortical/cerebellar activity ratios. As compared with controls, tracer uptake ratios in the DAT group were significantly reduced over all cortical regions, with the largest defects in the parieto-temporal and superior frontal cortices. A marked hypoperfusion affecting the superior and inferior frontal cortices was found in Pick's disease, whereas a mild but significant hypoperfusion was observed only in the superior frontal cortex of patients with PSP. In the DPD group, HMPAO uptake was significantly reduced in the parietal, temporal and occipital cortices, but not in the frontal cortex. These results show that DAT and DPD share an opposite anteroposterior HMPAO uptake defect as compared with the Pick's and PSP groups.

Topics: Aged; Alzheimer Disease; Brain; Dementia; Female; Humans; Male; Organotechnetium Compounds; Oximes; Parkinson Disease; Supranuclear Palsy, Progressive; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tc-99m hexamethylpropylene amineoxime (HMPAO) is a novel radiopharmaceutical demonstrated to be a sensitive indicator of abnormalities of cerebral perfusion. Most reports in the literature have evaluated patients with gross perfusion deficits, such as cerebrovascular accidents, and with dementia, where patterns of diffuse perfusion deficit were reported comparable with those seen in PET studies. We report a patient in whom there was the rapid onset of dementia, with the HMPAO images demonstrating diffuse loss of cortical perfusion in a nonfocal, and nonsegmental, fashion. Correlation with postmortem examination demonstrates good concordance between the diffuse nature of HMPAO loss, and diffuse cortical necrosis throughout both cerebral hemispheres. The technique was shown to be more sensitive than transmission CT scanning in demonstrating the extent of the deficit, and it correlated closely with the functional deficits noted in the patient.

Topics: Acute Disease; Brain; Cerebral Cortex; Cerebrovascular Circulation; Dementia; Humans; Male; Middle Aged; Necrosis; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

We compared I-123 IMP and 99m-Tc HMPAO SPECT studies with 0-15 H2O and F-18 FDG PET studies, and evaluated the clinical significance of SPECT studies in dementia. Seventeen patients including 9 patients with Alzheimer's disease, 3 patients with Pick's disease and 5 patients with multi-infarct dementia were studied. IMP and HMPAO SPECT studies could not detect mildly affected areas when compared with FDG PET. However, they revealed decreased perfusion in the bilateral parietal regions in Alzheimer's disease and in the bilateral frontal regions in Pick's disease, while MRI and/or CT showed mild to moderate cerebral atrophy. IMP and HMPAO SPECT studies can be easily performed in clinical practice, and these findings were useful in the differential diagnosis of dementia. Our preliminary results suggested that SPECT studies with I-123 IMP and Tc-99m HMPAO, despite their limitations, are useful in the differential diagnosis of dementia.

Topics: Aged; Alzheimer Disease; Amphetamines; Dementia; Dementia, Multi-Infarct; Female; Humans; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

A new semi-automatic method for quantifying regional cerebral uptake of 99m technetium-hexamethylpropylene amine oxime (99mTc-HMPAO) was used to assess single photon emission tomograms from 5 normal subjects, 14 patients with Alzheimer's disease, 14 patients with dementia of frontal lobe type and 4 patients with dementia with motor neurone disease. Uptake in both posterior cortical regions, although not in other regions, was significantly lower (P less than 0.05) in Alzheimer's disease than in normal controls. Conversely in both dementia of frontal lobe type and dementia with motor neurone disease, uptake was significantly reduced (P less than 0.05) compared with controls in all anterior cortical regions but not in posterior regions. Numerical findings in each disease mirrored the pattern of reduced tracer uptake previously reported by visual assessment. Nine patients were re-examined after an interval of at least 1 year. Comparison of follow-up scans with original images showed significant decreases in mid-anterior, left anterior and left posterior cortical uptake (P less than 0.01) in patients with Alzheimer's disease and in left middle, left posterior and right posterior cortical uptake (P less than 0.01) in patients with dementia of frontal lobe type. The method of quantification may be a useful adjunct to the visual assessment of single photon emission tomograms.

Topics: Alzheimer Disease; Brain; Dementia; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Brain; Dementia; Encephalitis; Female; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The annular single-crystal brain camera (ASPECT) is a digital SPECT system with a single-crystal sodium iodide thallium Nal(Tl) ring detector and collimator system designed to view the patient's head from three angles simultaneously. The ring is rotated concentrically to the detector for three-dimensional reconstruction over a 21.4 cm (diameter) by 10.7 cm (length) field of view. We evaluated the system clinically by imaging a Hoffman brain phantom and seven subjects, of whom two were normal controls, three had previous cerebral infarction and two had dementia. The ASPECT system produced tomographic images of high spatial resolution. In normal subjects, the separation of striata from thalami by the posterior limbs of the internal capsules was much clearer on ASPECT images than on rotating gamma camera images. The high spatial resolution obtained with the ASPECT system translates into superior anatomical representation of the brain compared to the standard rotating gamma camera.

Topics: Adult; Aged; Brain; Cerebral Infarction; Cerebrovascular Circulation; Dementia; Equipment Design; Female; Gamma Cameras; Humans; Male; Middle Aged; Models, Structural; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Brain Diseases; Dementia; Humans; Huntington Disease; Organotechnetium Compounds; Oximes; Parkinson Disease; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Alzheimer Disease; Cerebral Cortex; Cerebrovascular Circulation; Dementia; Dementia, Multi-Infarct; Humans; Huntington Disease; Organotechnetium Compounds; Oximes; Parkinson Disease; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Brain perfusion SPECT imaging has been applied to patients with dementia using 123I-IMP and 99mTc-HM-PAO. Brain blood flow closely parallels regional brain metabolism or brain function with normal cerebrovascular function. Therefore neuronal activity can be indirectly evaluated by in vivo brain perfusion imaging in dementia. This nuclear medicine technique is quite useful for the differential diagnosis, assessment of the degree and localization of the affected area, disease course, and therapeutic effect. IMP seems to be superior to HM-PAO in detecting focal decreased perfusion and quantitative analysis. Hereafter the brain perfusion SPECT study will be more widespread. Neuroreceptor imaging is highly expected as the next step of a brain SPECT study.

Topics: Adult; Aged; Aged, 80 and over; Amphetamines; Brain; Cerebrovascular Circulation; Dementia; Female; Humans; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The acute effects of intravenously administered L-acetylcarnitine (LAC) were evaluated with single-photon emission computed tomography (SPECT) and 99mTc-hexamethylpropyleneamine oxime in 30 demented patients (21 with a clinical diagnosis of Alzheimer's dementia and 9 with mixed-type dementia). Two SPECT scans were performed: in basal conditions, and 30 min after the administration of 500, 1,000, 1,500, or 2,000 mg LAC intravenously. Tracer activity ratios were determined in 10 pairs of cerebellar, cortical and subcortical regions. After administration of the lowest dose of LAC, no changes from the basal values were observed in any of the regions examined. The higher doses of the drug significantly elevated the tracer activity in cortical regions, particularly in the parietal lobe, which showed an impaired regional cerebral blood flow in the basal study. These effects of LAC and their relation with the cholinomimetic properties of the drug are discussed.

Topics: Acetylcarnitine; Aged; Alzheimer Disease; Carnitine; Dementia; Female; Humans; Injections, Intravenous; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Basal Ganglia Diseases; Brain; Dementia; Female; Humans; Huntington Disease; Male; Middle Aged; Organometallic Compounds; Oximes; Parkinson Disease; Radionuclide Imaging; Technetium; Technetium Tc 99m Exametazime

Topics: Aged; Cerebrovascular Circulation; Dementia; Female; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder.

Topics: Acquired Immunodeficiency Syndrome; Adult; Amphetamine; Brain; Dementia; Diagnosis, Differential; Electroencephalography; Female; Humans; Iodine Radioisotopes; Magnetic Resonance Imaging; Male; Middle Aged; Neurologic Examination; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the "on-off" syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the "on-off" syndrome studied during an "on" phase (under levodopa therapy) and on another occasion after withdrawal of levodopa ("off") demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on "off") and thalamus (higher on "off"). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Alzheimer Disease; Brain; Cerebrovascular Circulation; Dementia; Female; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Parkinson Disease; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution [99mTc]-HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias.

Topics: Aged; Atrophy; Brain; Dementia; Female; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Topics: Alzheimer Disease; Brain; Dementia; Humans; Huntington Disease; Ischemic Attack, Transient; Organometallic Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Single photon emission tomographic imaging of the brain using 99mTc HM-PAO was carried out in patients with a clinical diagnosis of Alzheimer's disease, non-Alzheimer frontal-lobe dementia, and progressive supranuclear palsy. Independent assessment of reductions in uptake revealed posterior hemisphere abnormalities in the majority of the Alzheimer group, and selective anterior hemisphere abnormalities in both other groups. The findings were consistent with observed patterns of mental impairment. The imaging technique has potential value in the differential diagnosis of primary cerebral atrophy.

Topics: Aged; Alzheimer Disease; Atrophy; Brain Ischemia; Dementia; Dominance, Cerebral; Female; Frontal Lobe; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Supranuclear Palsy, Progressive; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Technetium-99m hexamethylpropyleneamineoxime ([99mTc]HM-PAO) brain single photon emission computed tomography (SPECT) was performed with a dual head rotating scintillation camera. Normal tracer distribution and side/side differences of counting rates were obtained in 11 healthy volunteers. Almost stable gray/white matter ratios were found (1.97-2.1) in one normal subject during 2 hr after tracer administration. Eighty-three investigated patients had the following diagnoses (in parentheses is percent of positive findings in each group): cerebral vascular disease 18 (94.4%), epilepsy 23 (82.6%), extrapyramidal disorders 8 (100%), dementia 12 (100%), headache 11 (63.6%), psychiatric disorders 11 (27.3%). In addition, SPECT was performed in 28 male volunteers during motor or visual imagery tasks and a significant increase (p = 0.035) of relative tracer deposition was observed in the left inferior occipital region during visual imagery when compared with motor imagery. The results indicate that [99mTc]HM-PAO SPECT is valuable for demonstrating pathologic and physiologic changes of the brain.

Topics: Adult; Aged; Basal Ganglia Diseases; Brain; Cerebrovascular Circulation; Cerebrovascular Disorders; Dementia; Epilepsy; Female; Headache; Humans; Imagination; Male; Mental Disorders; Middle Aged; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Pure sensory stroke (PSS) is typically caused by a lacunar infarct located in the ventral-posterior (VP) thalamic nucleus contralateral to the paresthetic symptoms. The lesion is usually so small that it cannot be seen on computerized tomography (CT), as illustrated by our case. In our moderately hypertensive, 72-year-old patient with PSS, CT scanning and conventional nuclear magnetic resonance imaging (NMRI) scanning using a 7-mm-thick slice on a 1.5 Tesla instrument all failed to visualize the thalamic infarct. Using the high-resolution mode with 2-mm slice thickness it was, however, clearly seen. In addition, NMRI unexpectedly showed diffuse periventricular demyelinization as well as three other lacunar infarcts, i.e., findings characteristic of subcortical arteriosclerotic encephalopathy (SAE). This prompted psychometric testing, which revealed signs of mild (subclinical) dementia, in particular involving visiospatial apraxia; this pointed to decreased function of the right parietal cortex, which was structurally intact on CT and NMRI. Single photon emission computerized tomography by Xenon-133 injection and by hexamethyl-propyleneamine-oxim labeled with Technetium-99m showed asymmetric distribution of cerebral blood flow (CBF), with an 18% lower value in the right parietal cortex compared to the left side; this indicated asymmetric disconnection of the cortex by the SAE. Thus, the tomograms of the functional parameter, CBF, correlated better with the deficits revealed by neuropsychological testing than by CT or NMRI.

Topics: Aged; Brain; Brain Diseases; Cerebrovascular Circulation; Cerebrovascular Disorders; Dementia; Humans; Intracranial Arteriosclerosis; Magnetic Resonance Imaging; Male; Organometallic Compounds; Oximes; Syndrome; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Xenon Radioisotopes

After having outlined the importance of evaluating, in cerebral diseases, the regional cerebral blood flow by means of a non invasive method, the advantages of SPECT with Tc99m HM-PAO compared to the SPECT with radioxenon and iodoamphetamine are point out. The results obtained with this method on 28 different patients, six of with were normal subjects, while the remaining 22 were suffering: six from cerebro vascular disease, four from epilepsy, three from TIA, six from dementia, two from depressive syndrome and one from hemicrania are reported. The comparison of the results with literature references, proves that the tracer employed is definitely superior to TCT, while there is a coincidence with SPECT data obtained with radioxenon and iodoamphetamine. The radiotracer employed can be successfully used, due to its convenient physical-chemical features, in a daily routine, for the evaluation of regional cerebral blood flow in encephalic diagnostics.

Topics: Adult; Aged; Brain Diseases; Cerebrovascular Disorders; Dementia; Depressive Disorder; Diagnosis, Differential; Epilepsy; Evaluation Studies as Topic; Humans; Middle Aged; Oximes; Reference Values; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed