technetium-tc-99m-exametazime and Amnesia

Single photon emission computer tomography (SPECT) applied early in the course of Alzheimer's disease (AD) may identify regions with impaired brain function. Moreover, it may be relevant to characterize SPECT perfusion patterns in patients with mild cognitive impairment (MCI), in particular the subgroup of MCI patients with isolated amnesia, as these patients have been demonstrated to convert to AD in more than half of the cases within 3 years. The primary aim of the present study was to characterize the regional cerebral blood flow (CBF) in patients with neuropsychologically verified isolated amnesia. We examined 32 patients (11 men/21 women) with isolated amnesia according to strict neuropsychological criteria and 15 healthy volunteers (11 men/4 women). All subjects had an SPECT-99mTc-d,l-HMPAO perfusion study and neuropsychological assessments. Cranial MRI or CT was performed in all subjects. Semiquantitative (cerebellar relative) flow values were calculated and statistically compared. Patients with isolated amnesia had significant hypoperfusion in several cortical regions of interest compared to control subjects, most prominently in the left temporal cortex. Additionally, there was a trend towards globally reduced CBF in the patients, although this was not significant. These findings may indicate the presence of a progressive degenerative illness affecting multiple brain regions at its early or preclinical stage.

Topics: Adult; Aged; Aged, 80 and over; Amnesia; Cerebellum; Cerebrovascular Circulation; Female; Humans; Ischemia; Male; Middle Aged; Neuropsychological Tests; Psychiatric Status Rating Scales; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The regions of significant correlation between cerebral hypoperfusion and neuropsychological assessment scores were evaluated using (99m)Tc-HMPAO SPECT in patients with mild cognitive impairment (MCI) on the basis of its three subtypes, namely, single-domain amnestic MCI (aMCI-s), multiple-domain amnestic MCI (aMCI-m), and nonamnestic MCI (naMCI), following which comparisons were made among the three subtypes of MCI.. Regions of hypoperfusion were determined by comparing the three groups with the normal group. Neuropsychological assessment included tests to evaluate attention, language and related functions, visuospatial function, memory, frontal-executive function, and mini-mental state examination and depression scores. Regions of cerebral hypoperfusion were identified by comparing the three groups of MCI patients with the normal group (P<0.05, uncorrected). One-way analysis of variance was used to examine differences across groups, and post-hoc a-priori pairwise comparisons were used for between-group analyses. The regions of significant correlation, related to the neuropsychological assessment scores, were identified by simple regression of SPM8 within the masking image of the area of cerebral hypoperfusion (P<0.05, uncorrected).. The regions of cerebral hypoperfusion were identified by comparing members of the normal group with patients with aMCI-s, aMCI-m, and naMCI. The patients with aMCI-m showed significant correlation with all neuropsychological assessment scores, but the patients with aMCI-s correlated with four neuropsychological assessment scores of attention. The patients with naMCI revealed no significantly correlated regions (P<0.05, uncorrected). The regions that correlated with neuropsychological assessment scores in patients with aMCI-s were very small compared with those in patients with aMCI-m. The correlated regions in patients with aMCI-m were restricted to the left cerebrum and cerebellum. Brain areas showed significant correlation between neuropsychological assessment scores and hypoperfusion, which was evaluated by simple regression with the threshold being P less than 0.05, uncorrected. Rey complex figure test 20 min delayed, Korean-color word stroop test word reading, and Korean mini-mental state examination scores correlated more strongly with cerebral hypoperfusion compared with other assessment scores.. The specific pattern of significant correlation of cerebral hypoperfusion with neuropsychological assessment scores was classified into three subtypes (aMCI-s, aMCI-m, and naMCI) according to the patients' deficits in their cognitive domains.

Topics: Aged; Amnesia; Brain; Case-Control Studies; Cognitive Dysfunction; Female; Humans; Male; Middle Aged; Neuropsychological Tests; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The Development of Screening Guidelines and Clinical Criteria of Predementia Alzheimer's Disease (DESCRIPA) multicenter study enrolled patients with MCI or subjective cognitive complaints (SUBJ), a part of whom underwent optional brain perfusion SPECT. These patients were classified as SUBJ (n = 23), nonamnestic MCI (naMCI; n = 17) and amnestic MCI (aMCI; n = 40) based on neuropsychology. Twenty healthy subjects formed the control (CTR) group. Volumetric regions of interest (VROI) analysis was performed in six associative cortical areas in each hemisphere. ANOVA for repeated measures, corrected for age and center, showed significant differences between groups (p = 0.01) and VROI (p < 0.0001) with a significant group-region interaction (p = 0.029). In the post hoc comparison, SUBJ did not differ from CTR. aMCI disclosed reduced uptake in the left hippocampus and bilateral temporal cortex (compared with CTR) or in the left hippocampus and bilateral parietal cortex (compared with SUBJ). In the naMCI group, reduced VROI values were found in the bilateral temporal cortex and right frontal cortex. In the comparison between aMCI and naMCI, the former had lower values in the left parietal cortex and precuneus. Discriminant analysis between SUBJ/CTR versus all MCI patients allowed correct allocations in 73 % of cases. Mean VROI values were highly correlated (p < 0.0001) with the learning measure of a verbal memory test, especially in the bilateral precunei and parietal cortex and in the left hippocampus. In a subset of 70 patients, mean VROI values showed a significant correlation (p < 0.05) with the white matter hyperintensities score on MRI. In conclusion, MCI subtypes have different perfusion patterns. The aMCI group exhibited a pattern that is typical of early Alzheimer's disease, while the naMCI group showed a more anterior pattern of hypoperfusion. Instead, a homogeneous group effect was lacking in SUBJ.

Topics: Aged; Alzheimer Disease; Amnesia; Analysis of Variance; Attention; Brain; Cerebral Cortex; Cerebrovascular Circulation; Cognition; Cognition Disorders; Female; Frontal Lobe; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Neuropsychological Tests; Severity of Illness Index; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Verbal Learning

Aim of this study was to find cerebral perfusion correlates of conversion to dementia in patients with amnestic MCI.. 17 healthy subjects (age = 69 +/- 3, 9 females), and 23 amnestic MCI patients (age = 70 +/- 6, 10 females) underwent brain MR scan and (99m)Tc ECD SPECT. Conversion to AD was ascertained on average 19 +/- 10 months after baseline: 9 had converted (age = 69 +/- 3, 4 females), and 14 had not (age = 71 +/- 8, 6 females). We processed SPECT images with SPM2 following an optimized protocol and performed a voxel-based statistical analysis comparing amnestic MCI patients converted to AD and non-converted to dementia vs controls. We assessed the effect of gray matter atrophy on the above results with SPM2 using an optimized Voxel-Based Morphometry (VBM) protocol. We compared significant hypoperfusion with significant atrophy on a voxel-byvoxel basis.. In comparison with normal controls, amnestic MCI patients who converted to AD showed hypoperfusion in the right parahippocampal gyrus and left inferior temporal and fusiform gyri,whereas those who did not convert showed hypoperfusion in the retrosplenial cortex, precuneus and occipital gyri, mainly on the left side. We found no overlap between significant atrophy and significant hypoperfusion regions.. Parahippocampal and inferior temporal hypoperfusion in amnestic MCI patients appears as a correlate of conversion to AD; hypoperfusion in the retrosplenial cortex is involved in memory impairment but does not seem the key prognostic indicator of conversion to dementia.

Topics: Aged; Alzheimer Disease; Amnesia; Analysis of Variance; Brain Mapping; Cerebrovascular Circulation; Disease Progression; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A healthy 7-year-old girl developed emotional incontinence and amnesia associated with mumps encephalitis. Her neurologic findings markedly improved after treatment of daily injection of thyrotropin-releasing hormone tartrate without any adverse effects. Although magnetic resonance imaging revealed no abnormal findings, the findings of Tc-hexamethylpropyleneamine oxime single photon emission computed tomography demonstrated abnormality of left temporooccipital area thought to be responsible for her symptoms.

Topics: Affective Symptoms; Amnesia; Child; Encephalitis, Viral; Female; Humans; Magnetic Resonance Imaging; Mumps; Technetium Tc 99m Exametazime; Thyrotropin-Releasing Hormone; Tomography, Emission-Computed, Single-Photon

Loss of psychic self-activation has been described after bilateral lesions to the globus pallidus, striatum, and white matter of the frontal lobes, but it is a very rare sign of bithalamic lesions. The exact functional-anatomic mechanism underlying loss of psychic self-activation following bithalamic lesions remains to be elucidated.. We present clinical, neuropsychological, structural, and functional neuroimaging data of an 18-month follow-up period of a man with prominent loss of psychic self-activation after coronary arteriography. Except for memory decline, accompanying symptoms remained restricted to the acute phase. The neurobehavioral syndrome consisted mainly of apathy, indifference, poor motivation, and flattened affect, and this remained unchanged during the entire follow-up period. MRI showed a bithalamic infarction involving the nucleus medialis thalami bilaterally. Single-photon emission CT revealed a severe relative hypoperfusion of both thalami, a relative hypoperfusion of both nuclei caudati, and a relative hypoperfusion mesiofrontally.. Single-photon emission CT data support the hypothesis that the neurobehavioral manifestations after bithalamic paramedian infarction are caused by disruption of the striatal-ventral pallidal-thalamic-frontomesial limbic loop. Probably, bilateral disruption at different levels of the striatal-ventral pallidal-thalamic-frontomesial loop may lead to a similar clinical picture consisting of loss of psychic self-activation.

Topics: Affect; Amnesia; Arousal; Awareness; Cerebral Infarction; Functional Laterality; Humans; Intelligence Tests; Male; Middle Aged; Motivation; Radiopharmaceuticals; Self Concept; Stroke; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

The aim of this study was to investigate the pattern of regional cerebral blood flow changes associated with transient global amnesia (TGA).. HMPAO SPECT was performed in six consecutive patients during the acute phase of TGA. A follow-up SPECT was performed 3-20 wk later in four of the six patients. Semiquantitative analysis of 14 regions of interest, including the basal ganglia and the basal section of the temporal lobes, was performed by comparing patient data with control data obtained from a matched group of healthy subjects.. During TGA, unilateral or bilateral hypoperfusion of the temporo-basal region was observed in four patients. Variable hypoperfusion of further cortical areas was observed in five patients. Two patients who exhibited the most marked cortical hypoperfusion also showed striatal and thalamic hypoperfusion. These changes were normalized in the control studies obtained in four patients.. It remains unclear whether hypoperfusion during TGA represents a primary feature or a sequel of regional brain hypometabolism. Because hypoperfusion is not confined to the temporo-basal region or to the territory of the posterior cerebral artery, it is suggested that the origin of TGA-related changes lies at the level of subcortical structures that project diffusely to the cerebral cortex.

Topics: Acute Disease; Aged; Amnesia; Brain; Cerebrovascular Circulation; Female; Humans; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 60-year-old right-handed man developed disorientation, antegrade amnesia and transient mild clouding of consciousness. The antegrade amnesia persisted for more than one year after its onset. T2-weighted MR images showed high signal intensity in the left anteromedial thalamus. 99mTc-HM-PAO SPECT revealed decreased uptake in the left frontal and temporal lobes. These SPECT findings were still observed a year later. These findings suggest that functional involvement of the frontal and temporal lobe connections with the dorsomedial nucleus, anterior nucleus, and the mamillothalamic tract in the anteromedial part of thalamus were responsible for the prolonged antegrade amnesia. We think that SPECT findings are important for evaluating the outcome of thalamic amnesia.

Topics: Amnesia; Cerebral Infarction; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

Topics: Amnesia; Brain; Cerebral Cortex; Cerebrovascular Circulation; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Follow-Up Studies; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Previous reports about changes in cerebral blood flow (CBF) in transient global amnesia disclosed decreased flow in some parts of the brain. However, CBF analyses in most reports were qualitative but not quantitative. The purpose of this study was to determine changes in CBF in transient global amnesia.. The CBF was measured and the vasoreactive response to acetazolamide was evaluated in six patients with transient global amnesia using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). The CBF was measured during an attack in two patients and soon after an attack in the other four. About one month later, CBF was re-evaluated in each patient.. Two patients examined during an attack and one patient examined five hours after an attack had increased blood flow in the occipital cortex and cerebellum. Three patients examined at six to 10 hours after an attack had decreased blood flow in the thalamus, cerebellum, or putamen. These abnormalities of blood flow almost disappeared in all patients one month after onset. The vasodilatory response to acetazolamide, which was evaluated initially using SPECT, was poor in areas of increased blood flow. By the second evaluation of CBF with acetazolamide, the vasodilatory response had returned to normal.. In a patient with transient global amnesia, CBF increased in the vertebrobasilar territory during the attack and decreased afterwards. The vasodilatory response to acetazolamide may be impaired in the parts of the brain with increased blood flow. It is suggested that transient global amnesia is distinct from migraine but may share the same underlying mechanism.

Topics: Acetazolamide; Amnesia; Basilar Artery; Carbonic Anhydrase Inhibitors; Cerebellum; Female; Humans; Male; Middle Aged; Occipital Lobe; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Vertebral Artery

Topics: Amnesia; Epilepsy; Humans; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Time Factors; 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

The popular concept that cerebral ischemia causes transient global amnesia has been difficult to prove by cerebral blood flow studies during attacks because the transient global amnesia attacks are so short.. We performed single-photon emission computed tomography (SPECT) of the brain and neuropsychological assessment in a 37-year-old woman during a 10-hour attack and twice thereafter. A neuropsychological evaluation 3 hours after the onset of transient global amnesia revealed severe impairment of recent memory and verbal fluency, both of which returned to normal 2 and 28 days later, respectively. A 99mTc-labeled hexamethylpropyleneamine oxime SPECT of the brain performed 6 hours after the onset showed multiple perfusion defects in both occipital lobes, the medial left temporal lobe, and the left thalamus. A second brain SPECT performed 3 days later showed perfusion defects in only the occipital regions. A third brain SPECT performed 28 days later was normal. The patient's brain computed tomographic scan, electroencephalogram, duplex ultrasound of the carotid artery, and echocardiogram were normal.. The perfusion defects revealed by the brain SPECT during the transient global amnesia attack indicated ischemia in the territory of the posterior cerebral arteries, which partially resolved in 3 days and completely resolved by 28 days.

Topics: Adult; Amnesia; Brain Ischemia; Female; Hemiplegia; Humans; Neurologic Examination; Occipital Lobe; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Temporal Lobe; Thalamus; Tomography, Emission-Computed, Single-Photon

This is a report of a patient who underwent high-resolution brain perfusion SPECT studies during and after an episode of transient global amnesia. During the attack, SPECT imaging showed increased perfusion in the left medial temporal region involving the amygdala and hippocampus. After recovery from amnesia, a follow-up SPECT examination showed slightly decreased perfusion in this region. These findings support the hypothesis that transient global amnesia is associated with transient hyperperfusion in the medial temporal brain structures, and confirm the utility of high-resolution SPECT imaging for the evaluation of the fine details of functional brain anatomy.

Topics: Adult; Amnesia; Brain; Cerebrovascular Circulation; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Five right-handed patients with pure transient global amnesia were evaluated with technetium-99m hexamethylpropyleneamine oxime single photon emission computed tomography after the amnesic attack. Independent of the interval between the procedure and the amnesic episode, single photon emission computed tomography demonstrated a decreased cerebral blood flow in the left temporal lobe in one patient and in the left parietotemporal region in three patients, with a more marked reduction in the temporal lobe. The remaining three patients were normal. A control single photon emission computed tomographic study was carried out in one patient 3 months after the amnesic attack and showed a left-sided persistent temporal hypoperfusion. These findings suggest that in some patients, transient global amnesia can be due to a vascular mechanism requiring strong investigations for vascular risk factors and appropriate treatment. During a follow-up period of 12 to 32 months, none of the patients with regional hypoperfusion suffered cerebrovascular events, suggesting that single photon emission computed tomography has no predictive value for further stroke.

Topics: Aged; Amnesia; Brain; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Parietal Lobe; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Thirty six patients in the chronic stage after severe closed head injury were examined with tests of executive function, memory, intelligence, and functional capacities in daily living. Correlations were sought between test results and Tc-99m-HMPAO uptake of frontal, temporal, and thalamic regions assessed by SPECT. Neither the number of significant correlation coefficients between memory tests and regional uptake nor that between temporal uptake and tests exceeded chance. For the remaining tests, correlations to thalamic regions were stronger than those to the frontal regions, and those to right brain regions stronger than those to homologous left brain regions. Relationships of thalamic isotope uptake to neuropsychological performance may reflect the impact of diffuse brain damage and particularly of diffuse axonal injury on mental capacities.

Topics: Adult; Amnesia; Brain; Brain Damage, Chronic; Female; Follow-Up Studies; Frontal Lobe; Glasgow Coma Scale; Head Injuries, Closed; Humans; Male; Mental Processes; Mental Recall; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

We report a patient who was evaluated neuropsychologically and with single photon emission computed tomography (SPECT) during and after an episode of transient global amnesia. During the attack, there was patchy retrograde amnesia and an inability to learn both verbal and non-verbal material. SPECT showed severe bitemporal hypoperfusion. Serial neuro-psychological testing documented a rapid recovery of recognition, but delayed recovery in reproduction of learned information. Recovery of spontaneous verbal and figural fluency was even further delayed. Follow up SPECT examination showed a recovered cerebral perfusion. This case supports the hypothesis that TGA is associated with transient hypoperfusion of bilateral medial-temporal brain structures and suggests an additional involvement of structures responsible for drive and initiation.

Topics: Aged; Amnesia; Amnesia, Retrograde; Female; Humans; Magnetic Resonance Imaging; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon