technetium-tc-99m-exametazime and Syndrome

The aim of this work is to present whether SPECT

Topics: Aged; Brain; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Perfusion; Statistics, Nonparametric; Supranuclear Palsy, Progressive; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 60-year-old woman presented with a rare case of hyperperfusion syndrome after stent placement for subclavian artery stenosis manifesting as dizziness due to vertebrobasilar insufficiency. Three days after undergoing stent placement to treat the severely stenotic (90%) right subclavian artery, she suffered intracranial hemorrhage related to hyperperfusion syndrome. Preoperative single-photon emission computed tomography findings of low cerebral perfusion and poor perfusion reserve might indicate the possibility of hyperperfusion syndrome after stenting in patients with subclavian artery stenosis.

Topics: Cerebral Angiography; Female; Humans; Hyperemia; Intracranial Hemorrhages; Magnetic Resonance Angiography; Middle Aged; Risk Factors; Stents; Subclavian Steal Syndrome; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Vertebrobasilar Insufficiency

Corticobasal syndrome (CBS) has a heterogeneous neuropathological spectrum, ranging from the classical corticobasal degeneration to Alzheimer's disease (AD). The neuropathology of CBS is still unpredictable. CSF tau/abeta ratio is a reliable marker of AD.. To evaluate the presence of a distinct clinical and neuroimaging CBS phenotype according to CSF pattern.. 30 patients fulfilling current clinical criteria for CBS entered the study. Each patient underwent a clinical and standardised neuropsychological assessment, and CSF analysis (total tau and abeta42 dosages). CSF AD-like pattern and CSF non-AD like pattern (nAD-like) were identified. In 23 CBS cases, (99m)Tc-ECD single photon emission computed tomography (SPECT) scan was performed and analysed by statistical parametric mapping.. CSF AD-like pattern was reported in six cases (20%). The two subgroups did not differ in demographic characteristics or global cognitive impairment. The AD-like group showed greater impairment of memory performances, language and psychomotor speed while the nAD-like group had more severe extrapyramidal syndrome with comparable apraxia scores. Voxel by voxel analysis on SPECT images demonstrated that CBS AD-like patients had greater hypoperfusion in the brain areas typically affected by AD-namely, precuneus, posterior cingulate and hippocampus, bilaterally-compared with nAD-like patients (p<0.001). No clusters above the pre-established threshold were detected when nAD-like were compared with AD-like patients.. CSF AD-like profile in CBS is associated with earlier memory impairment and brain abnormalities typically found in classical AD. These findings argue for the usefulness of CSF testing to identify AD in CBS, and might suggest a different pharmacological approach on the basis of biological data.

Topics: Aged; Alzheimer Disease; Amyloid beta-Peptides; Basal Ganglia; Biomarkers; Cerebral Cortex; Female; Humans; Male; Middle Aged; Neurodegenerative Diseases; Neuropsychological Tests; Peptide Fragments; Predictive Value of Tests; Syndrome; tau Proteins; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Fahr's disease is a rare neurodegenerative syndrome, characterized by massive symmetrical intracerebral calcifications of the basal ganglia, dentate nuclei of the cerebellum, and the adjacent parenchyma. Computerized tomography (CT) is considerably more sensitive to detect these intracranial calcifications than other imaging modalities. The clinical, CT scan, and 99(m)Tc-D,L-hexamethylpropylene amine oxime (99(m)Tc-HMPAO) brain perfusion single-photon emission computerized tomography (SPECT) findings in a 42-year-old woman with Fahr's disease are reported, and the clinical utility of 99(m)Tc-HMPAO SPECT findings in Fahr's disease is discussed in this article. In conclusion, 99(m)Tc-HMPAO brain perfusion SPECT seems to be useful in the clinical approach to Fahr's disease, and may provide more specific and clinically relevant information when compared with anatomical imaging.

Topics: Adult; Brain; Brain Diseases; Calcinosis; Female; Humans; Neurodegenerative Diseases; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Body Image; Brain; Child; Female; Hallucinations; Humans; Illusions; Perceptual Disorders; Radiopharmaceuticals; Syndrome; 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

The acceleration forces infringing the cervical spine in whiplash injury are frequently associated with multiple cerebral symptoms. The purpose of this study was to determine whether there is a correlation between cerebral perfusion findings, P300 recording (an electrophysiologic marker of cognitive ability), and neuropsychological tests in patients with whiplash injury.. Twenty patients with chronic whiplash injury underwent extensive clinical evaluation and neuropsychological testing. A brain single-photon emission computed tomography (SPECT) study using 99mTc-HMPAO was performed in all patients within 24 hours of neuropsychological evaluation. P300 event-related potentials were performed in 15 patients and in 9 normal volunteers.. Thirteen of 20 patients had brain perfusion abnormalities on the SPECT studies, in one or more regions. Eight of 15 patients had abnormal P300 studies. Seven of eight patients with abnormal P300 had also an abnormal SPECT study. Seven of 15 patients had normal P300 results, 6 of them with a normal SPECT and 1 with SPECT abnormalities. There was no significant correlation between the SPECT findings or the P300 results and the scores of attention and working memory. There was, however, close agreement between the SPECT and P300.. SPECT perfusion abnormalities in patients with chronic whiplash syndrome correlate well with P300 recording. The combination of these studies with neurocognitive and neurobehavioral tests may be useful in identifying a subgroup of patients having organic brain lesions.

Topics: Adult; Aged; Cerebrovascular Circulation; Event-Related Potentials, P300; Female; Humans; Male; Middle Aged; Neuropsychological Tests; Radiopharmaceuticals; Regression Analysis; Statistics, Nonparametric; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Whiplash Injuries

The cases of three children, 16, 12, and 12 years of age, who suffered sudden confusional state and cortical blindness lasting 12 to 30 minutes while under treatment with high-dose methotrexate, cyclophosphamide, and dactinomycin for a lower limb osteosarcoma are reported. Transient neuropsychologic deficits arose after the acute phase of treatment: left hemispatial neglect and constructive apraxia (Patient 1); constructive apraxia (Patient 2); and constructive apraxia and alexia without aphasia (Patient 3). The three patients recovered completely from all their deficits within the time frame of 3 hours to 2 weeks. Arterial hypertension and hypomagnesemia were found during the acute phase in all patients. In Patients 2 and 3, magnetic resonance imaging revealed increased parieto-occipital T(2) signal involving gray and white matter. In Patients 1 and 2, HmPAO-SPECT revealed parieto-occipital hypoperfusion that resolved a few days later. The alterations detected by neuroimaging were concurrent with the appearance and disappearance of the clinical symptoms. Such transient acute episodes have been named occipital-parietal encephalopathy. On the basis of our clinical, laboratory, and neuroimaging findings, an explanation for the origin of this syndrome, a migrainelike mechanism, triggered by chemotherapy-induced hypomagnesemia, is proposed.

Topics: Acute Disease; Adolescent; Antineoplastic Combined Chemotherapy Protocols; Brain; Child; Cyclophosphamide; Dactinomycin; Female; Humans; Hypertension; Magnesium Deficiency; Male; Methotrexate; Neurotoxicity Syndromes; Osteosarcoma; Radiopharmaceuticals; Remission Induction; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Brain Diseases; Carotid Artery Thrombosis; Carotid Artery, Internal; Cerebellar Diseases; Cerebral Infarction; Child; Female; Heart Septal Defects; Humans; Radiopharmaceuticals; Spleen; Syndrome; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Whole-Body Counting

Topics: Aged; Colon; Colonic Diseases; Female; Humans; Radionuclide Imaging; Radiopharmaceuticals; Syndrome; Technetium Tc 99m Exametazime

Alice in Wonderland syndrome (AIWS) is characterized by visual hallucinations and bizarre perceptual distortions. Technetium-99m hexamethylpropyleneamine tomography (SPECT) brain scans were performed in four patients during the acute stage of AIWS. Two patients were demonstrated to have Epstein-Barr virus infections. One had abnormal (EEG) findings. The visual-evoked potential, cranial CT, and MRI findings were negative. The decreased cerebral perfusion areas in all patients were near the visual tract and visual cortex. All involved some regions of the temporal lobe. In most patients with AIWS, the EEG, CT, and MRI are unable to determine the precise pathologic areas. However, a SPECT brain scan may demonstrate abnormal perfusion areas and explain the clinical presentations.

Topics: Cerebrovascular Circulation; Electroencephalography; Epstein-Barr Virus Infections; Female; Hallucinations; Humans; Infant; Male; Perceptual Disorders; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Visual Cortex; Visual Pathways

The purposes of this study were: (1) to determine the prevalence of abnormal 99mTc-HMPAO SPECT scans in patients suffering from persistent post-concussive syndrome (PPCS) after mild closed head injury (CHI); (2) to compare SPECT with structural neuroimaging (MRI and CT) in patients with mild CHI; and (3) to investigate correlations between SPECT and clinical data obtained from the patient sample (neuropsychological testing, demographics, psychiatric diagnoses). Forty-three patients were included. SPECT was read as abnormal in 53% of patients and showed a total of 37 lesions while MRI was read as abnormal in 9% and CT scan in only 4.6% of patients after mild CHI. SPECT appears to be more sensitive in detecting cerebral abnormalities after mild CHI, especially in patients with PPCS symptoms, than either CT or MRI. No statistically significant relationship was found between SPECT scan abnormalities and age, past psychiatric history, history of substance abuse, or history of multiple CHI. Education level did not differ between patients with normal and abnormal SPECT. Current neuropsychiatric symptoms did not seem to have any impact on the results of SPECT scan.

Topics: Adolescent; Adult; Brain Concussion; Brain Damage, Chronic; Cerebral Cortex; Dominance, Cerebral; Energy Metabolism; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Regional Blood Flow; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Aged; Cerebellar Nuclei; Cerebellum; Cerebral Cortex; Cerebral Infarction; Cerebrovascular Circulation; Humans; Male; Mesencephalon; Neural Pathways; Ophthalmoplegia; Organotechnetium Compounds; Oximes; Pons; Radiopharmaceuticals; Syndrome; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

The aim of this case report was to present a patient with complete anarthria and orofacial apraxia without other relevant neurological deficit. The clinical features are compatible with anterior operculum syndrome.. A regional brain perfusion scan was done using 99mTc-HMPAO and a SPECT gamma camera. A brain CT scan and an MRI were also performed.. Brain CT and MRI were not diagnostic. On brain SPECT, hypoperfusion of the left inferior area of the frontal lobe was noted.. The patient studied showed an uncommon case of anterior operculum syndrome of focal degenerative origin localized by SPECT. SPECT may be a useful and effective method for diagnosis of this unusual neurological deficit.

Topics: Aged; Apraxias; Brain; Deglutition Disorders; Dysarthria; Humans; Male; Organotechnetium Compounds; Oximes; Radiopharmaceuticals; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A case study is presented to illustrate a rare condition described by Cotard as "délire de négation". The central symptom is a nihilistic delusion with denial of one's own existence of oneself and that of the external world. In the present case, the syndrome became manifest as an escalation of a recurrent depressive disorder late in life. After initial resistance to therapy, the syndrome was successfully treated with electroconvulsive therapy. For the first time, we report the regional cerebral blood flow measured by 99mTc-HMPAO-SPECT before and after therapy. Before treatment, significant bitemporal hypoperfusion relative to the cerebellum was found, which was no longer demonstrable on remission.

Topics: Aged; Delusions; Denial, Psychological; Depressive Disorder; Dominance, Cerebral; Electroconvulsive Therapy; Follow-Up Studies; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Syndrome; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Two patients with SUNCT syndrome (short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing) were investigated. Blood flow velocity in the middle cerebral artery was monitored before, during, and outside four spontaneous attacks. An interhemispheric asymmetry was observed. In the second case, velocity decreased significantly on both sides during attacks in comparison with preattack values. Cerebral SPECT (single photon emission computed tomography) images were obtained during a bout and between attacks in one patient. The radiocompound was injected 5 to 10 seconds after the start of an attack. In both patients, normal tracer uptake and symmetric perfusion was observed during headache periods.

Topics: Aged; Blood Flow Velocity; Brain; Cerebrovascular Circulation; Cluster Headache; Conjunctival Diseases; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Sneddon syndrome is defined as a clinical entity consisting of livedo racemosa generalisata (LRG) and cerebrovascular lesions, which often lead to physical and mental handicaps. Four patients with LRG and the suspected diagnosis of Sneddon syndrome had HMPAO-SPECT studies. The patients underwent CT and/or MR brain imaging and three patients had Duplex sonography of the cerebral arteries (TCD). Brain SPECT was abnormal in all patients, whereas CT/MRI revealed a cerebral lesion in only one patient and all TCD studies were normal. HMPAO-SPECT is valuable in detecting disturbed regional cerebral blood flow before irreversible ischemic insults occur, thus allowing the diagnosis of Sneddon syndrome at an early stage.

Topics: Adult; Brain; Cerebrovascular Circulation; Cerebrovascular Disorders; Diagnostic Imaging; Female; Humans; Organotechnetium Compounds; Oximes; Skin Diseases, Vascular; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The pathogenesis of neurologic and neuropsychologic dysfunction in HIV-1 infection is unclear. The purpose of the study was to determine an association between cerebral perfusion and HIV-1-related ocular microangiopathic syndrome.. We studied 28 HIV-1-infected patients, seven of whom presented with asymptomatic HIV infection, nine with lymphadenopathy syndrome or AIDS-related complex, and 12 with AIDS. Cerebral perfusion was semi-quantitatively measured by single photon emission computed tomography of the brain using technetium-99 hexamethyl-propylenamine oxime (HMPAO-SPECT). The conjunctival manifestation of HIV-1-related microangiopathic syndrome was measured by a rating scale determining blood-flow sludging and, retinal cotton-wool spots were counted. CD4 count, neopterin, beta 2-microglobulin (beta 2M), haemoglobin, and age were determined as putative confounding variables.. Mean conjunctival sludge in patients with normal HMPAO-SPECT findings was 1.3 +/- 0.5 (mean +/- s.e.m.); no cotton-wool spots were present. In patients with slightly impaired HMPAO-SPECT, it was 2.1 +/- 0.6 and mean cotton-wool spot count was 1.1 +/- 0.4. In patients with severely impaired HMPAO-SPECT, mean conjunctival sludge was 4.5 +/- 0.3 and mean cotton-wool spot count was 4.9 +/- 1.1 HMPAO-SPECT findings were closely associated with conjunctival sludge (r = 0.72; P < 0.001) and number of cotton-wool spots (r = 0.78; P < 0.001), whereas only a slight association with staging of HIV disease was found (P = 0.052). Analysis of covariance controlling for CD4 count neopterin, beta 2M, age, and haemoglobin demonstrated a significant difference between the three HMPAO-SPECT groups for both the number of cotton-wool spots (P < 0.001) and the conjunctival sludge rating (P < 0.001).. There was a close association between severity of HIV-1-related ocular microangiopathic syndrome and severity of cerebral hypoperfusion. Microvascular alterations might contribute to the pathogenesis of neurological and neuropsychological symptoms in patients with HIV-1 disease. Furthermore, the conjunctival sludge rating and the number of cotton-wool spots might be appropriate indicators for severity of microvascular changes of the central nervous system [corrected].

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; AIDS-Related Complex; beta 2-Microglobulin; Biopterins; Brain; CD4-Positive T-Lymphocytes; Conjunctiva; Conjunctival Diseases; Hemoglobins; HIV Infections; HIV-1; Humans; Leukocyte Count; Male; Microcirculation; Middle Aged; Neopterin; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Assessment of cerebral perfusion may elucidate pathogenesis of Landau-Kleffner syndrome (LKS). We obtained 99mTc-HMPAO SPECT studies in five children with LKS and in three children with syndromes of verbal-auditory agnosia. In LKS, perfusion showed temporoparietal asymmetry (9.56% +/- 3.44%) (n = 4) or bilateral parietal abnormality (n = 1). SPECT in non-LKS patients was normal (n = 1), showed (n = 1) totihemispheral hypoperfusion accompanying structural abnormality or (n = 1) a pattern resembling but distinct from LKS. Seizures in LKS patients had never occurred (n = 1), were controlled satisfactorily (n = 2), or poorly (n = 2). Maximum EEG abnormality was left centrotemoral-occipital (n = 1), left frontocentral (n = 1), bitemporal/left central (n = 1), and left central/parasagittal (n = 1). Asymmetric temporoparietal perfusion appears characteristic of LKS, differing from findings in other childhood linguistic disturbances. This abnormality occurs across a spectrum of seizure expression, diverging from the distribution of EEG abnormalities. The SPECT abnormalities parallel PET-defined LKS metabolic abnormalities, and may indicate central pathogenetic features of the disorder.

Topics: Aphasia; Apraxias; Brain; Child; Child, Preschool; Electroencephalography; Epilepsy; Female; Humans; Image Processing, Computer-Assisted; Male; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The authors describe a patient with Rasmussen's syndrome detected by grossly abnormal results of Tc-99m HMPAO SPECT brain imaging obtained with a single-headed camera. Results of magnetic resonance imaging and cerebrospinal fluid examinations were normal.

Topics: Brain; Child, Preschool; Chronic Disease; Encephalitis; Epilepsies, Partial; Female; Hemiplegia; Humans; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Sneddon syndrome is a non-inflammatory, non-atherosclerotic disease involving small and medium-sized arteries of the brain and of the skin. The arteriographic examination is often negative despite progressive impairment of the neurological status. In 3 patients with Sneddon syndrome cerebral perfusion was assessed with single photon emission computerized tomography (SPECT) and technetium99 m-hexamethylpropylenamineoxime (Tc99 HM PAO). A correlation between clinical and SPECT finding was found, with significant focal reduction of regional cerebral blood flow (rCBF) in the two more severely affected patients.

Topics: Adult; Brain; Cerebrovascular Disorders; Female; Humans; Middle Aged; Organotechnetium Compounds; Oximes; Perfusion; Skin Diseases; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Single-photon emission computed tomography (SPECT) of the brain using hexamethyl propylene amine oxime (HMPAO) was performed in a 37-year-old patient suffering from mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). Reduced blood flow was observed bilaterally in the parieto-occipital regions (resembling Alzheimer type dementia) and in the right parietal lobe.

Topics: Acidosis, Lactic; Adult; Alzheimer Disease; Brain Diseases; Cerebrovascular Disorders; Diagnosis, Differential; Humans; Male; Mitochondria, Muscle; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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 six patients included in this study had painful dysesthesia, resulting from vascular lesions in or near the thalamus, confirmed by computerized tomography(CT) brain scan. Using hexamethyl propyleneamine oxime(HM-PAO) single photon emission computed tomography(SPECT) brain scanning, regional cerebral perfusion(rCP) was demonstrated. In contrast to three patients with lesions near the thalamus who showed symmetrical cortical radioactivity, the other three patients with thalamic lesions revealed decreased rCP in the ipsilateral cerebral cortex on HM-PAO brain SPECT. We thought that the loss of afferent activating stimuli from the thalamus led to decreased cortical neuronal activity and the following hypoperfusion. In patients with thalamic syndrome resulting from thalamic lesions, the role of the remote effect of the thalamic damage and consequent cortical deregulation in the development of thalamic pain and/or neuropsychological symptoms cannot be excluded completely.

Topics: Brain; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Pain; Syndrome; Technetium; Technetium Tc 99m Exametazime; Thalamic Diseases; Tomography, Emission-Computed, Single-Photon

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