technetium-tc-99m-exametazime and Atrophy

Topics: Adult; Aged; Atrophy; Brain; Cerebral Hemorrhage; Electroencephalography; Epilepsy; Humans; Magnetic Resonance Imaging; Middle Aged; Prospective Studies; Radiography; Radiopharmaceuticals; Retrospective Studies; Severity of Illness Index; Stroke; Technetium Tc 99m Exametazime; Time Factors

Intracranial aneurysms in the pediatric age group are rare occurrences. They usually present with subarachnoid hemorrhage or mass effect. Their association with epilepsy has rarely been reported; such concurrence may not be a coincidence. We present a 16-year-old girl with a 5-year history of medically intractable complex partial seizures. Preoperative electrophysiological and neuroimaging studies demonstrated an epileptogenic focus and atrophy in the right mesial temporal lobe, and ipsilateral incidental aneurysm at the carotid artery bifurcation. The patient underwent a complete right anterior temporal lobectomy, followed by clipping of the aneurysm. We concluded that the epilepsy management in association with cerebral aneurysms is controversial, but when surgery is indicated, clipping of the aneurysm and resection of the epileptogenic focus may provide the optimal outcome. The relevant literature is reviewed and the possible mechanisms of production of epilepsy by intracranial aneurysms are discussed.

Topics: Adolescent; Atrophy; Cerebral Angiography; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Humans; Intracranial Aneurysm; Magnetic Resonance Imaging; Psychosurgery; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

To examine the utility of single-photon emission computed tomography (SPECT) to predict conversion from mild cognitive impairment (MCI) to Alzheimer disease (AD).. Longitudinal, prospective study.. University-based memory disorders clinic.. One hundred twenty seven patients with MCI and 59 healthy comparison subjects followed up for 1-9 years.. Diagnostic evaluation, neuropsychological tests, social/cognitive function, olfactory identification, apolipoprotein E genotype, magnetic resonance imaging, and brain Tc hexamethyl-propylene-aminoxime SPECT scan with visual ratings, and region of interest (ROI) analyses were done.. Visual ratings of SPECT temporal and parietal blood flow did not distinguish eventual MCI converters to AD (N = 31) from nonconverters (N = 96), but the global rating predicted conversion (41.9% sensitivity and 82.3% specificity, Fisher's exact test p = 0.013). Blood flow in each ROI was not predictive, but when dichotomized at the median value of the patients with MCI, low flow increased the hazard of conversion to AD for parietal (hazard ratio: 2.96, 95% confidence interval: 1.16-7.53, p = 0.023) and medial temporal regions (hazard ratio: 3.12, 95% confidence interval: 1.14-8.56, p = 0.027). In the 3-year follow-up sample, low parietal (p <0.05) and medial temporal (p <0.01) flow predicted conversion to AD, with or without controlling for age, Mini-Mental State Examination, and apolipoprotein E ε4 genotype. These measures lost significance when other strong predictors were included in logistic regression analyses: verbal memory, social/cognitive functioning, olfactory identification deficits, hippocampal, and entorhinal cortex volumes.. SPECT visual ratings showed limited utility in predicting MCI conversion to AD. The modest predictive utility of quantified low parietal and medial temporal flow using SPECT may decrease when other stronger predictors are available.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Apolipoprotein E4; Atrophy; Brain; Cerebrovascular Circulation; Cognition Disorders; Disease Progression; Female; Genotype; Humans; Male; Middle Aged; Oximes; Predictive Value of Tests; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

This study investigated the hypothesis that the combination of regional CT brain atrophy measurements and semiquantitative SPECT regional blood flow ratios could produce a diagnostic test for Alzheimer's disease (AD) with an accuracy comparable to that achieved with the present clinical gold standard of the NINCDS-ADRDA criteria.. Single proton emission computed tomography (SPECT) and CT head scans were performed on 122 subjects referred an UBC Alzheimer clinic and diagnosed as either 'not demented' (ND-37) or 'possible/probable AD' (AD-85) by the NINCDS-ADRDA criteria. Stepwise discriminant analysis (SDA) was performed on the bilateral SPECT regions of interest and compared to bilateral CT qualitative/quantitative assessment in the frontal, parietal and temporal lobes to determine which were most accurate at ND/AD distinction. Receiver operating curves (ROC) were then constructed for these variables individually and for their combined discriminant function.. The left temporal qualitative cortical atrophy score (CT) and left temporal perfusion ratio (SPECT) were selected in the SDA. The combined discriminant function was more specific at AD/ND distinction than either of CT or SPECT alone. The accuracy of AD/ND distinction with the combined discriminant function was below that achieved by clinical diagnosis according to the NINCDS-ADRDA criteria and was not significantly different from that achieved with SPECT or CT alone as defined by ROC curve analysis.. The measurements of left temporal cortical atrophy and regional cerebral blood flow were most indicative of AD; however they lacked the sensitivity and specificity to recommend their use as a diagnostic test for AD.

Topics: Aged; Alzheimer Disease; Atrophy; Brain; Cerebral Cortex; Cerebrovascular Circulation; Female; Functional Laterality; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Firstly, to compare the findings of interictal 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and of single photon emission computed tomography (SPECT) using 99mTc-hexamethyl propylene-amine-oxime (HMPAO) and 123I-iomazenil in localising the epileptogenic cortex in patients who were candidates for epilepsy surgery, but in whom clinical findings, video EEG monitoring (V-EEG), MRI, and neuropsychological evaluations did not give any definite localisation of the seizure onset. Secondly, to assess the ability of these functional methods to help in the decision about the epilepsy surgery.. Eighteen epileptic patients were studied with FDG-PET and iomazenil-SPECT. HMPAO-SPECT was performed in 11 of these 18 patients. Two references for localisation was used--ictal subdural EEG recordings (S-EEG) and the operated region.. Fifteen of 18 patients had localising findings in S-EEG. FDG-PET findings were in accordance with the references in 13 patients and iomazenil-SPECT in nine patients. HMPAO-SPECT visualised the focus less accurately than the two other methods. In three patients S-EEG showed independent bitemporal seizure onset. In these patients FDG-PET showed no lateralisation. However, iomazenil-SPECT showed temporal lobe lateralisation in two of them.. FDG-PET seemed to localise the epileptogenic cortex more accurately than interictal iomazenil-SPECT in patients with complicated focal epilepsy.

Topics: Adolescent; Adult; Atrophy; Cerebral Cortex; Electroencephalography; Epilepsy; Female; Flumazenil; Fluorodeoxyglucose F18; Glucose; Humans; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

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

We describe 5 patients with complex visual disturbances in the absence of ocular pathology who were ultimately diagnosed with posterior cortical atrophy (PCA). The presence of visual cortical symptoms, neuroimaging findings and clinical evolution led to the diagnosis 1-5 years after the onset of visual symptoms. Age of onset ranged from 50-66 years. In 3 cases, magnetic resonance imaging (MRI) of the brain demonstrated predominantly right posterior cortical atrophy. The other 2 patients had nonspecific MRI findings but the diagnosis was established given the findings on clinical examination and positron emission tomography (PET). All progressed to global dementia and an autopsy confirmed the diagnosis of Alzheimer disease in one patient. The possibility of PCA should be considered when a patient presents with complex visual symptoms in the absence of ocular pathology. Early neurological assessment may avoid diagnostic delay.

Topics: Aged; Atrophy; Brain Diseases; Cerebral Cortex; Female; Fluorodeoxyglucose F18; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Positron-Emission Tomography; Retrospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Vision Disorders

A Japanese male developed gradual loss of spontaneous speech at age 60. Three years later meaningful speech had deteriorated to the point that it had become restricted to monotonous utterances. Neuropsychological examination at age 62 showed that he had severe non-fluent aphasia. A brain MRI demonstrated mild cortical atrophy with ischemic lesions in the cerebral white matter. He was diagnosed as having primary progressive aphasia. At age 63, he was admitted to the hospital to reevaluate the neurological condition. Neurologic examination showed severe non-fluent aphasia, hyperreflexia, snout and sucking reflexes. No alien hand was observed. He was able to walk, dress, wash himself and use chopsticks as well as name real objects. At age 65, 99Tc-hexamethylpropyleneamine oxime single photon emission computed tomography (HMPAO-SPECT) revealed diffuse cerebral hypoperfusion that was particularly prominent in the left frontal lobe. An MRI showed progressive cortical atrophy with the definite atrophy of the left paracentral gyrus. The hippocampal formation and putamen were also atrophic. He died of pneumonia at age 67. The brain weighed 810 g with atrophy of the frontal lobe, globus pallidus, enlargement of the lateral ventricles and depigmentation of the substantia nigra. Microscopic examination showed severe neuronal loss and gliosis in the cerebral cortex, globus pallidus interna and substantia nigra. Ballooned neurons were observed in the cerebral cortex. Gallyas-Braak method revealed numerous astrocytic plaques and argentophilic threads in the cerebrum. Clinical diagnosis of corticobasal degeneration sometimes is difficult in individuals with atypical clinical presentations. More exact clinical and radiological criteria may warrant a diagnosis of corticobasal degeneration.

Topics: Aphasia, Primary Progressive; Atrophy; Brain; Fatal Outcome; Frontal Lobe; Gliosis; Globus Pallidus; Hippocampus; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Putamen; Radiopharmaceuticals; Substantia Nigra; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The current clinical practice of reporting images obtained with single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethylpropylene amine oxime (99mTc HMPAO) images was examined by having 16 experts evaluate the appearance of SPECT images in patients with probable Alzheimer type dementia (ATD), patients with major depressive episode (DSM-IV), and healthy volunteers. The experts rated diagnostic criteria of scan appearance in respect of importance for their individual diagnostic practice. Experts were nuclear medicine specialists, psychiatrists and physicists taking part in a European multi-centre collaborative project. They examined 158 perfusion scans and then the same perfusion scans together with statistical parametric maps (SPMs). The sensitivity of experts' diagnostic judgments was significantly and negatively correlated with the importance they attributed to reduced regional perfusion in the parietal lobes. A corresponding positive correlation was observed for diagnostic specificity against depressed and healthy volunteers. Similar results were observed with SPMs, where in addition area under the receiver operating characteristic (ROC) curve was significantly reduced with raters' increased diagnostic reliance on frontal lobe perfusion deficits. Sensitivity was greater with SPM for patients younger than 70 years and with dementia severity. The more importance experts placed on parietal (symmetrical) perfusion deficits, the less sensitive and the more specific their diagnostic judgment was. Using multiple raters in large patient samples may provide a way of identifying successful explicit diagnostic strategies for clinical image analysis.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Atrophy; Brain; Brain Ischemia; Cerebral Cortex; Depressive Disorder, Major; Diagnosis, Differential; Dominance, Cerebral; Female; Humans; Image Processing, Computer-Assisted; Male; Mental Status Schedule; Middle Aged; Parietal Lobe; Personality Inventory; ROC Curve; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Rasmussen's encephalitis (RE) is a rare, progressive, chronic encephalitis characterised by drug-resistant epilepsy, progressive hemiparesis and mental impairment. It typically involves only one cerebral hemisphere, which becomes atrophic. We present neuroradiological findings in 13 children with RE. MRI was performed in all patients, fluorodeoxyglucose positron-emission tomography (PET) in three, Tc-99m hexamethylpropylenamine oxime single-photon emission computed tomography (SPECT) in two and proton MR spectroscopy ((1)HMRS) in two. MRI showed progression of the hemisphere atrophy, always prevalent in the region primarily involved (13 patients), spread of the abnormal signal in white matter (11) and cortex (10) and progression of atrophy of the head of the caudate nucleus (nine). Associated secondary changes were: atrophy of the contralateral cerebellar hemisphere (in four patients), the ipsilateral hippocampus (in five) and the brain stem (in five). The earliest CT and MRI abnormalities, seen between 1 day and 4 months after the first seizure (in 12 patients examined, nine of whom had MRI) in one cerebral hemisphere included: high signal on T2-weighted images in the cortex (seven patients) and white matter (nine), cortical atrophy usually involving the frontoinsular region, with mild or severe enlargement of the lateral ventricle (eight) and moderate atrophy of the head of the caudate nucleus (seven). Cortical swelling in the early stage of the disease was recognisable only in two patients. PET revealed hypometabolism, SPECT decreased perfusion, and (1)HMRS reduction of N-acetylaspartate in the affected hemisphere. PET and SPECT were usually performed in the late stages and did not provide specific findings. MRI thus demonstrates the progression of RE and may suggest the diagnosis in the early stages, often before the appearance of neurological deficits. Early diagnosis of RE may be crucial for selecting patients for aggressive medical therapy or major surgical interventions such as hemispherectomy.

Topics: Atrophy; Brain; Child; Child, Preschool; Diagnosis, Differential; Disease Progression; Encephalitis; Female; Fluorodeoxyglucose F18; Humans; Infant; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Protons; Radiopharmaceuticals; Retrospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

A 23-year-old woman with Gerstmann-Straussler-Scheinker disease (GSS) was investigated by 1H-magnetic resonance spectroscopy (1H-MRS). She developed gait ataxic at 22 years. The diagnosis was confirmed by DNA analysis showing a proline-to-leucine point mutation at codon 102 of the prion protein. On 1H-MRS, she showed a remarkable reduction of the N-acetylaspartate/creatine ratio in the frontal lobe, cerebellar hemisphere and vermis and putamen. MRI revealed mild atrophy of the cerebellar hemispheres and vermis and cerebral cortex, but single-photon emission computed tomography (SPECT) with 99mHMPAO showed normal perfusion in the cerebellum. The imaging studies suggest that MRS might be superior to MRI or SPECT for detection of early neuronal degeneration.

Topics: Adult; Atrophy; Brain; Cerebellum; Codon; DNA Mutational Analysis; Female; Gerstmann-Straussler-Scheinker Disease; Humans; Magnetic Resonance Imaging; Pedigree; Point Mutation; Protons; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; AIDS-Related Opportunistic Infections; Atrophy; Blindness; Brain; Female; Humans; Meningitis, Cryptococcal; Optic Nerve; Prognosis; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Perfusion and metabolic studies in patients with Alzheimer's disease (AD) have so far yielded conflicting results on the functional status of the hippocampal region, whose deep location in the brain makes it critical to optimize the image-reconstruction technique employed in emission tomography. We used a brain-dedicated device (CERASPECT) to perform single photon emission computed tomography (SPECT) studies with 99mTc-hexamethylpropylene-amine-oxime in 22 consecutive patients (mean age: 74+/-6.5 years) with mild [mini-mental status examination (MMSE) score > or =15, mean 20.8+/-3.2], probable AD. The control subjects were 11 healthy elderly people (mean age: 70.5+/-6.5 years). In patients, the total score on the selective reminding test (SRT) was used as an index of memory function. Counts from a hippocampal and a temporoparietal region of interest in each hemisphere were referred to the average thalamic counts. To optimize SPECT images, we used conventional filtered back-projection (FBP) reconstruction and a new iterative method of conjugate gradients (CG), which takes into account the geometrical and physical characteristics of the gamma-camera. Hippocampal perfusion in the two hemispheres was significantly lower in patients than in control subjects, regardless of which reconstruction method was used, and correlated with the MMSE score. The correlation between hippocampal perfusion and the SRT score was significantly (bootstrap procedure) higher with the CG method than with the FBP method (CG: r=0.52 and 0.54; FBP: r=0.39 and 0.47, for the right and left hemisphere, respectively). These results show hippocampal hypoperfusion in patients with mild AD, a correlation between hippocampal perfusion and the severity of cognitive impairment, and enhanced identification of these subtle perfusional changes with the use of an alternative image-reconstruction method that improves the spatial resolution of SPECT images.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Atrophy; Case-Control Studies; Cerebrovascular Circulation; Cognition Disorders; Female; Hippocampus; Humans; Male; Middle Aged; Parietal Lobe; Radiopharmaceuticals; Severity of Illness Index; Technetium Tc 99m Exametazime; Temporal Lobe; Thalamus; Tomography, Emission-Computed, Single-Photon

The aims of this study were to develop an objective method for assessing rCBF deficits using a statistical image analysis protocol and to validate its effective use in clinical practice. 99Tcm-HMPAO brain SPET images were acquired for 40 normal subjects, 10 patients with Alzheimer's disease and 10 patients with depression. Automated image registration was used to standardize the size and shape of the brain structures for all subjects. The images of the first 30 normal subjects were used to construct a normal database. The CBF images of the other 10 normal subjects and the 20 patients were compared voxel by voxel with the normal database to map CBF abnormalities by statistical evaluation. The results were compared with the clinical reports of CBF images. The expert system detected all rCBF deficits reported by the nuclear physicians. Some additional areas with special information, like atrophy and bilateral asymmetry, were also identified by the expert system. We conclude that this expert system can delineate CBF deficits with sufficiently high accuracy, differentiating normal from abnormal CBF images using voxel-based comparisons. The use of an expert system improves rCBF SPET image evaluation.

Topics: Aged; Alzheimer Disease; Atrophy; Brain; Cerebral Arteries; Cerebrovascular Circulation; Data Interpretation, Statistical; Databases, Factual; Depression; Expert Systems; Humans; Image Interpretation, Computer-Assisted; Image Processing, Computer-Assisted; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors report serial technetium-99m hexamethylpropylene-amine-oxime brain single photon emission computed tomography (SPECT) findings in two infants with Gaucher's disease type 2. Detailed neurologic and laboratory examinations, including bone marrow biopsies and enzymatic assays, were described. Serial brain magnetic resonance imaging studies in one patient illustrated the progressive cerebral atrophy in the frontal and temporal lobes. The SPECT in both cases demonstrated positive findings of initial scattered hypoperfusion, with extending to hypoperfusion of the entire cerebrum after 4 months of clinical deterioration. These changes in the SPECT findings may reflect progressive degeneration of the cerebrum in Gaucher's disease type 2. Brain SPECT may provide useful information on cerebral flow and metabolic distribution corresponding to the neurologic deficits of neuronopathic Gaucher's disease.

Topics: Atrophy; Brain; Cerebral Cortex; Cerebrovascular Circulation; Disease Progression; Gaucher Disease; Humans; Infant; Longitudinal Studies; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors report a 61-year-old man with chronic viral encephalitis and Koshevnikov syndrome occurring 42 months after initial symptom of right hemiparesis. Serial computed tomography of the brain showed changes in the attenuation of the left temporal lobe lesion over time. Magnetic resonance images of the brain showed enlargement of left temporoparietooccipital lobes with cortical gyral enhancement on T1-weighted images following intravenous administration of gadolinium-DTPA. 99mTc-HMPAO single-photon emission computerized tomography showed increased radioactivity and hyperperfusion in the left temporoparietal region with paradoxically decreased local tissue perfusion at the contralateral right hemisphere. Follow-up magnetic resonance images of the brain 4 years later showed atrophy of bilateral cerebral hemispheres. We postulate that a "transcallosal diaschisis" with subsequent degeneration is a possible mechanism. A brain biopsy from the left temporal lobe lesion showed pictures compatible with viral encephalitis probably herpes simplex encephalitis.

Topics: Atrophy; Brain; Brain Diseases; Cerebrovascular Circulation; Chronic Disease; Contrast Media; Corpus Callosum; Encephalitis, Viral; Epilepsia Partialis Continua; Follow-Up Studies; Gadolinium DTPA; Herpes Simplex; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Occipital Lobe; Parietal Lobe; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

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: Adult; Aged; Amyotrophic Lateral Sclerosis; Atrophy; Brain; Family Health; Frontal Lobe; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Parietal Lobe; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

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

To determine the frequency and patterns of periictal cerebellar hyperperfusion, whether it is associated with increased cerebellar atrophy, and whether cerebellar hyperperfusion and cerebellar atrophy are associated with predisposing clinical factors or with the outcome of epilepsy surgery.. Periictal and interictal SPECT scans and volumetric brain magnetic resonance imaging (MRI) were quantitatively analyzed in 54 consecutive patients with medically refractory partial epilepsy. Their histories were reviewed and their postsurgical outcomes assessed.. Significant periictal cerebellar hyperperfusion was found in 26 (48.1%) patients, of whom 18 had CCH, two had homolateral cerebellar hyperperfusion (HCH), and six had symmetrical bilateral hyperperfusion (BCH). No relation found between the site of the SPECT seizure localization and the presence or type of cerebellar hyperperfusion. CCH was more common when the injected seizure involved unilateral clonic motor activity (p < 0.05). A smaller MRI relative cerebellar volume (cerebellar volume/cerebral volume) was correlated with a greater seizure frequency (Rs = -0.30; p < 0.05) but not with the duration of epilepsy. There was no difference in the cerebellar volumes between the different patterns of cerebellar perfusion (p > 0.05). However, patients without a focal structural MRI lesion had significantly smaller cerebellar volumes (p < 0.05). In patients who underwent epilepsy surgery (n = 31), there was a trend for those without excellent outcomes to have smaller relative cerebellar volumes than did those with excellent outcome (10.6 vs. 11.8%; p = 0.08).. Periictal changes in cerebellar perfusion, particularly CCH, are common in patients with intractable partial epilepsy. However, periictal hyperperfusion does not appear to be a major contributor to the development of cerebellar atrophy.

Topics: Adolescent; Adult; Aged; Atrophy; Cerebellar Diseases; Cerebellum; Child; Child, Preschool; Epilepsies, Partial; Epilepsy, Temporal Lobe; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Middle Aged; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Topics: Atrophy; Brain; Child; Female; Fontan Procedure; Humans; Postoperative Complications; Posture; Radiopharmaceuticals; 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

Topics: Anorexia Nervosa; Atrophy; Brain; Humans; Magnetic Resonance Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The value of functional and morphological neuroimaging in the early diagnosis of Alzheimer's disease (AD) is still debated. Described here are cerebral perfusion and linear measures of medial temporal lobe atrophy in 2 monozygotic twins discordant for AD who were investigated with technetium 99m-hexamethylpropy-leneamineoxime single-photon emission tomography (SPET) and magnetic resonance (MR) imaging. Both showed pathological cortical perfusion findings on SPET, while medical temporal lobe atrophy was present only in the affected twin. MR measures of medial temporal lobe atrophy have greater agreement with clinical data than do SPET measures of cerebral perfusion. Evaluation of atrophy may be useful in the early diagnosis of AD.

Topics: Activities of Daily Living; Alzheimer Disease; Atrophy; Cerebrovascular Circulation; Diseases in Twins; Electroencephalography; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Twins, Monozygotic

In 24 patients with vascular dementia of Binswanger's type (VDBT) and 14 age-matched neurologically normal volunteers, we investigated the relationship between clinical features, white matter lesions (leuco-araiosis) and cerebral atrophy on computed tomographic (CT) scan, and regional cerebral blood flow. All subjects underwent the Mini-Mental State Examination of Taiwan, version 1 (MMSE-T1), for assessing the severity of cognitive impairment. The patients were subdivided into two groups, one with mild to moderate (group I, MMSE-T1 scores: 11-24, n=11), and the other with severe dementia (group II, MMSE-T1 scores: below 10, n=13). White matter degeneration was evaluated with densitometric methods. Loss of brain parenchyma was estimated with seven linear measurements (Evan's ratio, third ventricle ratio, width of temporal horn tip, anterior-posterior length of temporal horn, anterior-posterior length of Sylvian fissure and width of frontal interhemispheric fissure) by CT scans. Regional cerebral blood flow was determined with technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomography (SPET). In neuroimaging studies, subcortical leuco-araiosis was localized at the frontal region in group I patients and scattered diffusely in group II patients. 99mTc-HMPAO SPET analysis revealed reduction of regional cerebral blood flow in the frontal lobe in group I patients and widespread reduction of regional cerebral blood flow in group II patients. A correlation between frontal leuco-araiosis and perfusion defect of the frontal pole was demonstrated in group I patients, showing findings typical of subcortical dementia. There was no difference in frontal atrophic measurements between group I patients and controls. Ratios of volumes of lost brain parenchyma and leuco-araiosis were significantly higher in group II patients than in the age-matched controls, corresponding to a diffuse cerebral perfusion defect. These results suggest that patients with VDBT have early frontal lobe involvement with posterior progression. Patients with mild VDBT are more likely to show reduction of frontal cerebral blood flow and leuco-araiosis, while those with severe VDBT are more likely to have diffuse leuco-araiosis, cerebral hypoperfusion and brain atrophy.

Topics: Aged; Atrophy; Brain; Case-Control Studies; Cerebrovascular Circulation; Dementia, Vascular; Female; Humans; Male; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

SPECT imaging with I-123 IMP or Tc-99m HMPAO was performed in two patients with Creutzfeldt-Jakob disease to evaluate abnormalities in brain perfusion. In the first patient, there was decreased perfusion of the left frontal, parietal, and temporal lobes. CT and MRI were negative. In the second patient, there was patchy perfusion and slightly decreased perfusion of the right hemisphere. MRI revealed slight brain atrophy and bilateral high intensity areas in the basal ganglia on T2 weighted images. Subsequent SPECT imaging revealed severely decreased perfusion of the entire brain. Subsequent MRI demonstrated severe brain atrophy.

Topics: Aged; Amphetamines; Atrophy; Brain; Creutzfeldt-Jakob Syndrome; Humans; Iodine Radioisotopes; Iofetamine; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Progressive clumsiness developed in the right hand of a 33-year-old man, became bilateral and evolved very slowly for ten years. Another neurological deficit was restricted to a slight impairment of superficial sensations. Magnetic resonance imaging verified an atrophy of bilateral parietal lobes. The cerebral blood flow was markedly decreased in the atrophic area. Pure clumsiness of a very slowly progressive course due to parietal atrophy has never been reported in such a young adult. This clinical picture may suggest another variety of degenerative process.

Topics: Adult; Apraxias; Atrophy; Brain; Cerebrovascular Circulation; Disease Progression; Hand; Humans; Magnetic Resonance Imaging; Male; Motor Cortex; Nerve Degeneration; Organotechnetium Compounds; Oximes; Parietal Lobe; Radionuclide Imaging; Technetium Tc 99m Exametazime

The role of interictal brain single-photon emission computed tomography (SPECT) was examined using (99mTc)- labeled hexamethylpropyleneamine oxime (HMPAO) in refractory partial epilepsy. The accuracy with which SPECT localized an epileptic focus and whether it predicted long-term postoperative seizure relief were assessed. Twenty patients were evaluated, 14 of whom ultimately had anterior temporal lobectomy with follow-up ranging from 41 to 56 months. A single-headed gamma camera was used. The interictal SPECT showed ipsilateral temporal hypoperfusion in 8 (47%) of 17 patients with temporal lobe epilepsy and showed either multilobar hypoperfusion or no perfusion defects in the rest. The sensitivity and specificity were similar in patients with a more complex clinical picture who required intracranial electrodes and those who did not. Presence or absence of temporal lobe hypoperfusion did not correlate with postoperative seizure relief. It is concluded that interictal SPECT with 99mTc-HMPAO with a single-headed gamma camera does not add useful information in preoperative localization or predicting postoperative seizure relief.

Topics: Adolescent; Adult; Atrophy; Brain; Cerebrovascular Circulation; Electroencephalography; Epilepsies, Partial; Follow-Up Studies; Forecasting; Humans; Middle Aged; Organotechnetium Compounds; Oximes; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Using brain computed tomography (CT) and single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc HM-PAO) in 13 patients with delayed neurologic sequelae after carbon monoxide poisoning, we tried to evaluate the clinical outcome of delayed CO sequelae. Among the 13 initial brain CTs, seven showed low density in the cerebral white matter and one revealed hypodensity in both globi pallidi. Of the 7 follow-up CT scans, 3 have remained unchanged, but in 4 cases more aggravating patterns with cortical atrophy without the clinical correlation were observed. There was no correlation between the CT findings and the outcome of delayed CO sequelae. All initial SPECTs in 13 patients with delayed CO sequelae showed diffuse patchy hypoperfusion throughout the cerebral cortex. Among the follow-up SPECTs in 7 patients, 6 patients showed increased cerebral perfusion with the concomitant clinical improvement, but the SPECT of a patient in bedridden state had remained unchanged, compared with the initial SPECT. There seemed to be good correlation between the findings of SPECT and the outcome of delayed CO sequelae. In conclusion, 99mTc HM-PAO brain SPECT is more sensitive than CT, and may be a useful test in evaluating the clinical outcome of delayed neurologic sequelae after CO poisoning.

Topics: Adult; Aged; Atrophy; Brain; Brain Damage, Chronic; Brain Mapping; Carbon Monoxide Poisoning; Carboxyhemoglobin; Cerebral Cortex; Disability Evaluation; Female; Follow-Up Studies; Globus Pallidus; Humans; Hypoxia, Brain; Male; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Three cases of Friedreich's ataxia were submitted to diverse neuroradiological procedures in order to determine the extent of atrophic processes in the central nervous system. All patients underwent computerized-tomography scan, Magnetic Resonance Imaging, and HMPA-single Photon emission computerized tomography studies, focusing in cerebellar lobes. A slight atrophy was observed in the vermis and the cerebellar lobes with CT scan and MRI. In contrast a significant decrease in cerebellar blood flow was shown by TC-HMPAE SPECT study. The significance of these findings in understanding physiopathological mechanisms in Friedreich's ataxia is discussed.

Topics: Adult; Atrophy; Cerebellum; Female; Friedreich Ataxia; Humans; Male; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebral atrophy often coexists with other brain disorders and by itself may alter the pattern of cerebral perfusion. If unrecognized, it may confound diagnoses based on brain single-photon emission tomography (SPET). In this retrospective study, we describe and evaluate criteria for the diagnosis of cerebral atrophy on technetium-99m hexamethylpropylene amine oxime brain SPET studies. The SPET scans of 11 patients with cerebral atrophy and ten controls were evaluated for the presence of a prominent interhemispheric fissure, presence of prominent cerebral sulci, separation of thalamic nuclei, and pronounced separation of caudate nuclei. The SPET studies were interpreted by two independent observers blind to the findings of magnetic resonance imaging, which provided the final diagnosis of cerebral atrophy. The combination of the four scintigraphic signs was accurate in the diagnosis of cerebral atrophy in 95% of the cases and had a sensitivity of 91% and a specificity of 100%.

Topics: Adult; Aged; Aged, 80 and over; Atrophy; Brain; Humans; Magnetic Resonance Imaging; Middle Aged; Organotechnetium Compounds; Oximes; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We reported a 28-year-old man with adrenoleukodystrophy showing neurological features of olivopontocerebellar atrophy. He had a 11-year history of Addison's disease. ACTH stimulation produced no rise in the plasma cortisol level. The ratios of C24:0/C22:0, C25:0/C22:0, and C26:0/C22:0 in fatty acids of sphingomyelin from plasma were all increased. MRI showed the atrophy of brainstem and cerebellum and the abnormal hyperintense lesions of the bilateral pyramidal tracts in the brainstem and internal capsule. 99mTc-HM PAO SPECT showed hypoperfusion of the deep white matter, frontal lobes, temporal lobes, and cerebellum. We suggest that SPECT may be useful for detection of subclinical lesions in ALD.

Topics: Adrenoleukodystrophy; Adult; Atrophy; Brain Stem; Cerebellum; Humans; Magnetic Resonance Imaging; Male; Olivopontocerebellar Atrophies; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

To determine the prevalence of central nervous system damage due to ethanol, we evaluated 40 asymptomatic chronic alcoholics and 20 age-matched controls. Studies included neuropsychological testing, brain 99mTc-HMPAO SPECT, and morphometric analysis by CT scan. In the qualitative analysis, 30 of the 40 alcoholics showed hypoperfused areas on SPECT scan. In the semiquantitative analysis, alcoholics exhibited significant reduction in regional cerebral blood flow (rCBF) ratio of all brain lobes compared to controls (p < 0.001). The rCBF ratio was mainly reduced in frontal lobes (65%). Only 11 alcoholics showed significant frontal lobe atrophy in the morphometric analysis; most also had abnormalities on SPECT scan. Alcoholics exhibited significant impairment of frontal tasks and visuospatial skills. Frontal test impairment was independently related to both frontal atrophy and hypoperfusion. In a group of ten alcoholics in whom another SPECT scan was performed after 2 mo of ethanol abstinence, rCBF ratio of the frontal lobes normalized in eight, without frontal atrophy. In patients without frontal atrophy, reduced rCBF ratio of the anterior portion of the frontal lobes correlated negatively with frontal test results (r = -0.6535, p < 0.001). A significant negative correlation between cerebral perfusion and the amount of ethanol consumed in the month prior to study was observed (r = -0.6289, p < 0.001). In conclusion, asymptomatic chronic alcoholics frequently showed reversible frontal lobe hypoperfusion, which is related to recent ethanol intake, reflects brain function impairment and is independent of brain atrophy.

Topics: Adult; Alcoholism; Atrophy; Brain; Brain Diseases; Cerebrovascular Circulation; Frontal Lobe; Humans; Male; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We report the SPECT, CT and CW Doppler findings in a series of 117 patients with cerebral ischemic lesions and correlate them with the clinical findings. SPECT-PAO proved to be more sensitive in localizing focal lesions than CT, which in 50% of the cases was normal or yielded an image of cerebral atrophy. In the latter cases CW Doppler ultrasound on the supraaortic trunks showed changes, circumscribed or diffuse. On the CW Doppler and SPECT evidence we consider that the CT image of cerebral atrophy may denote an alteration of the cerebral blood flow and metabolism and should be assessed in this light in the diagnosis and prognosis of cerebral ischemic lesions.

Topics: Adult; Aged; Atrophy; Blood Flow Velocity; Brain; Brain Ischemia; Cerebral Angiography; Cerebrovascular Disorders; Evaluation Studies as Topic; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Subtraction Technique; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Ultrasonography

Single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethylpropyleneamine oxime (99mTc-d,l-HMPAO) was used to determine global and regional CBF in 53 healthy subjects aged 21-83 years. For the whole group, global CBF normalized to the cerebellum was 86.4% +/- 8.4 (SD). The contribution of age, sex, and atrophy to variations in global CBF was studied using stepwise multiple regression analysis. There was a significant negative correlation of global CBF with subjective ratings of cortical atrophy, but not with ratings of ventricular size, Evans ratio, sex, or age. In a subgroup of 33 subjects, in whom volumetric measurements of atrophy were performed, cortical atrophy was the only significant determinant for global CBF, accounting for 27% of its variance. Mean global CBF as measured with the 133Xe inhalation technique and SPECT was 54 +/- 9 ml/100 g/min and did not correlate significantly with age. There was a preferential decline of CBF in the frontal cortex with advancing age. The side-to-side asymmetry of several regions of interest increased with age. A method was described for estimation of subcortical CBF, which decreased with advancing cortical atrophy. The relative area of the subcortical low-flow region increased with age. These results are useful in distinguishing the effects of age and simple atrophy from disease effects, when the 99mTc-d,l-HMPAO method is used.

Topics: Adult; Aged; Aged, 80 and over; Aging; Atrophy; Brain; Cerebellum; Cerebral Cortex; Cerebrovascular Circulation; Female; Frontal Lobe; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Five patients with Rasmussen's syndrome (sometimes known as smouldering encephalitis), are presented. This rare form of childhood epilepsy is characterized by intractable partial seizures with progressive neurological and mental impairment. Diagnostic brain biopsy shows the histological changes of active encephalitis, consistent with a viral infection. Although the raised cerebrospinal fluid (CSF) complement and interferon levels seen in some patients support this hypothesis, no infective agent has yet been isolated. All five patients were investigated by transmission computed tomography (CT) of the head, electroencephalography (EEG) and cerebral single-photon-emission computed tomography (SPECT) using 99Tcm-hexamethylpropylenamine oxime (HMPAO) and in addition 123I-amphetamine (IMP) in Patient 1. 99Tcm-HMPAO is now regarded as reflecting cerebral perfusion, whereas the uptake of 123I-amphetamine is more dependent on cell function. In all patients SPECT imaging demonstrated an area of hypoperfusion/hypometabolism which corresponded to the anatomical localization of the epiletogenic foci found by clinical assessment, EEG and CT. In all cases the SPECT study also demonstrated a more extensive area of abnormality than CT, and in the two patients who had sequential studies, alteration in the size of the defect was found which correlated with the patients' changing clinical condition. SPECT imaging in Rasmussen's syndrome may facilitate anatomical localization of the area of pathology, and may demonstrate a changing pattern in cerebral hypoperfusion/hypometabolism. It could also serve as a guide to accurate brain biopsy.

Topics: Amphetamines; Atrophy; Brain; Child; Electroencephalography; Encephalitis; Epilepsies, Partial; Female; Humans; Iodine Radioisotopes; Male; Organometallic Compounds; Oximes; Syndrome; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, X-Ray 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

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