Hexamethylpropylene Amine Oxime Single-photon Emission Research Articles

Regional Cerebral Blood Flow Correlates of Neuropsychiatric Symptom Domains in Early Alzheimer's Disease.

Although various neuropsychiatric symptoms are frequently accompanied with Alzheimer’s disease (AD) and pose a substantial burden to both patients and caregivers, their neurobiological underpinnings remain unclear. This study investigated associations between regional cerebral blood flow (rCBF) and neuropsychiatric symptom domains in early AD. A total of 59 patients with early AD underwent brain technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) scans. Neuropsychiatric symptoms were assessed by the Neuropsychiatric Inventory and clustered into the affective, apathy, hyperactivity, and psychotic domains. A voxel-wise multiple regression analysis was performed with four domain scores as independent variables and age, sex, and Mini-Mental State Examination scores as covariates. The affective domain score was negatively correlated with rCBF in the prefrontal cortex, thalamus, and caudate. The apathy domain score showed inverse correlations with rCBF in the prefrontal and pre/postcentral gyri and midbrain. Patients with higher hyperactivity domain scores had increased rCBF in the prefrontal and temporal lobes. The psychotic symptom domain was positively correlated with rCBF in the cuneus and negatively associated with rCBF in the prefrontal, cingulate, and occipital regions and putamen. The score of each neuropsychiatric symptom domain showed the differential correlates of brain perfusion, while altered rCBF in the prefrontal cortex was found in all domains. Although preliminary, our results may suggest common and distinct patterns of rCBF underlying neuropsychiatric symptoms in early AD. Further studies with larger samples and control participants are warranted to confirm these findings.

Brain Perfusion Correlates of Apathy in Alzheimer's Disease.

Background and PurposeApathy is one of the most common neuropsychiatric symptoms in patients with Alzheimer's disease (AD). It may have adverse impacts on the progression of AD. However, its neurobiological underpinnings remain unclear. The objective of this study was to investigate differences in regional cerebral blood flow (rCBF) between AD patients with apathy and those without apathy.MethodsSixty-six apathetic AD patients and 66 AD patients without apathy completed Neuropsychiatric Inventory (NPI) and underwent technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT) scans. Voxel-wise differences in rCBF between the 2 groups were examined. Association between rCBF and levels of apathy in the apathetic group was also assessed.ResultsAD patients with apathy showed lower rCBF in the bilateral orbitofrontal cortex, left putamen, left nucleus accumbens, left thalamus, and bilateral insula than those without (all p<0.005). Mean perfusion across all significant clusters showed a negative linear correlation with NPI apathy score in AD patients with apathy (β=−0.25; p=0.04).ConclusionsHypoperfusion in the prefrontal, striatal, and insular areas may be neural correlates of apathy in AD patients.

Changing Landscapes in the Neuroimaging of Dementia.

Neuroimaging in dementia has advanced several folds in the past decade. It has evolved from diagnosing secondary causes of dementia to the current use in identifying primary dementia and aid in clinically perplexing situations. There has been a leap in the imaging technology that can virtually dissect the brain with a high degree of radiopathological correlation. The neuroimaging in dementia is classified into structural, functional, and molecular imaging. Structural imaging includes voxel-based morphometry and diffusion tensor imaging. Functional imaging includes 18F-fluorodeoxy glucose positron emission tomography imaging, 99mTc hexamethylpropyleneamineoxime single photon emission computed tomography imaging, and functional magnetic resonance imaging studies. Molecular imaging includes amyloid imaging, tau imaging, and translocated protein imaging. These advancements have led to using neuroimaging as a biomarker in assessing the progression and also in deciphering prognosis of the disease. In this article, we discuss the current clinical relevance of these neurological advancements.

Comparison of regional cerebral blood flow in Parkinson's disease with depression and major depression

AbstractDiagnosis of depression in Parkinson's disease (PD) patients is complicated due to the overlapping symptoms of the two disorders. We investigated regional cerebral blood flow (rCBF) in patients with only major depression (MD) and PD patients with (PDMD) and without MD (PDNMD) using 99mTc hexamethylpropyleneamine oxime single photon emission computed tomography (HMPAO‐SPECT). A total of 103 patients (38 PDMD, 46 PDNMD, and 19 MD patients) underwent brain HMPAO‐SPECT scans. Voxel‐wise whole‐brain analysis was conducted to compare rCBF of the PDMD group with that of the PDNMD and MD groups. The scores of the Geriatric Depression Scale (GDS) and Neuropsychiatric Inventory (NPI) were significantly higher in the PDMD group than in the PDNMD group. The PDMD group showed significant hypoperfusion in the subcallosal cortex than the PDNMD group. The MD group showed significant hypoperfusion in the brainstem and inferomedial frontal region compared with the PDMD group. Our findings suggest that dysfunction of the inferomedial frontal cortex may be involved in the pathogenesis of depression in PD patients.

Associations between Brain Perfusion and Sleep Disturbance in Patients with Alzheimer's Disease.

Background and PurposeAlthough sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT).MethodsA total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups.ResultsThe two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group.ConclusionsThe AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.

Abstract WMP110: Improvement in Cortical Versus Subcortical Perfusion After Superficial Temporal Artery- Middle Cerebral Artery (MCA) Bypass in Patients With Severe Stenosis of Intracranial Carotid and MCA

Background and Objective: The role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We have recently reported the improvement in clinical and various cerebral hemodynamic parameters after STA-MCA bypass surgery for severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR). Using acetazolamide challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT), we evaluated the differential improvement in metabolic perfusion in cortical and subcortical structures after STA-MCA bypass surgery. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) for CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged SPECT and STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent SPECT at 4±1 months. Using automated image analyzer, we evaluated differences in metabolic perfusion in cortical and subcortical regions. Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR on SPECT. Fifty (60%) of them underwent STA-MCA bypass surgery. HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in all cases. Significantly better improvement (14.5%) in cerebral perfusion was noted in the cortical regions as compared to the subcortical regions (4.5%, p&lt;0.005). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in cerebral perfusion, especially in the cortical regions.

Neuroimaging referral for dementia diagnosis: The specialist's perspective in Ireland

BackgroundNeuroimaging is an increasingly important tool in the diagnostic workup of dementia. Neurologists, geriatricians, and old-age psychiatrists are involved in key tasks in the diagnostic process, frequently referring patients with suspected dementia for neuroimaging. MethodsThe research design was a postal survey of all geriatricians, old-age psychiatrists, and neurologists in the Republic of Ireland (N = 176) as identified by the Irish Medical Directory 2011–2012 and supplementary listings. ResultsAlmost 65% of specialists did not have access to 2-[18F]fluoro-2-deoxy-D-glucose positron emission (FDG-PET) or FDG-PET/computed tomography (CT), and 80.3% did not have access to perfusion hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) or dopaminergic iodine-123-radiolabeled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane SPECT. Most specialists (88.7%) referred patients with mild cognitive impairment or suspected dementia for magnetic resonance imaging (MRI), 81.7% referred for CT, and 26.8% for FDG-PET or FDG-PET/CT. Only 44.6% of respondents were aware of dementia-specific protocols for referrals for neuroimaging. ConclusionSpecialist access to imaging modalities other than CT and MRI is restricted. Improved access may affect patient treatment and care.

Abstract 74: Improvement in Cerebral Hemodynamic Parameters and Outcome after Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients with Severe Steno-occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective: Older and the recent extracranial-intracranial (EC/IC) bypass trials for symptomatic carotid occlusion failed to demonstrate reduction in stroke recurrence. However, role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated serial changes in various cerebral hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated with STA-MCA bypass surgery or medical treatment. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT). STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4±1 months and followed-up for cerebral ischemic events. Results: A total of 112patients (73males, mean age 56yrs; range 23-78yrs) were included. HMPAO-SPECT demonstrated impaired CVR in 77 (69%) patients. Of them, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1months showed significant improvement in STA-MCA bypass group. During follow-up (mean 34months; range 18-39months), only 6/46 (13%) patients in bypass group developed cerebral ischemic events as compared to 14/31 (45%) cases on medical therapy (absolute risk-reduction 32%, p=0.008). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Neurocognitive impairment in Susac syndrome: Magnetic resonance imaging and Tc-99m hexamethylpropyleneamine oxime single photon emission computed tomography correlation.

Susac syndrome is a clinical triad of branch retinal artery occlusions, sensorineural hearing loss, and encephalopathy. The characteristic central corpus callosum involvement in Susac syndrome is readily recognizable on conventional magnetic resonance imaging (MRI); however, the neurocognitive effect of these lesions is not well-understood. We present a case of Susac syndrome with typical MRI findings of central callosal lesions at diagnosis. The patient had a protracted clinical course and did not respond well to immunosuppression therapy. Follow-up brain single photon emission computed tomography with Tc-99m hexamethylpropyleneamine oxime revealed marked unilateral frontoparietal and temporal lobe hypoperfusion. Our case highlights the utility of functional neuroimaging to uncover the possible underlying white matter dysfunction, which is not otherwise detectable with conventional MRI techniques.

Efficacy of an NMDA receptor antagonist for Parkinson's disease dementia: A brain perfusion SPECT study

ABSTRACTMemantine's efficacy has been demonstrated in patients with moderate to severe Alzheimer's disease. However, memantine therapy is not typically used in treating Parkinson's disease dementia (PDD), although the deviating glutamatergic pattern evidenced in neuropathological findings suggests that N‐methyl D‐aspartate receptor antagonists in patients with Lewy‐body disorder may be effective. Therefore, we conducted this longitudinal study to confirm the efficacy of memantine for PDD by analyzing comparative changes in regional cerebral blood flow (rCBF) and neuropsychological tests before and after memantine administration in PDD. A total of 18 patients with PDD were enrolled in this study. All patients underwent technetium‐99m hexamethylpropyleneamine oxime single photon emission computed tomography and completed neuropsychological tests before and 12 months after memantine administration. This study showed that there was no significant difference in cognitive functioning before and after memantine administration. No significant difference in rCBF was observed in any regions at baseline compared to 12 months after memantine administration. Our results suggest that memantine delays the speed of deterioration in cognitive functioning and behavioral symptoms in PDD because we found no significant changes in rCBF and cognition after memantine treatment.

Akinetic Mutism Without a Structural Prefrontal Lesion

Akinetic mutism is characterized by profound apathy and a lack of verbal and motor output for action, despite preserved alertness. The condition usually follows bilateral damage to the medial frontal subcortical circuits. We report a 59-year-old right-handed woman who was admitted to the neurology ward with sudden-onset akinetic mutism. Her medical history included an ischemic stroke 3 years earlier, with residual anomia and mild agraphia but no motor dysfunction. On this admission, a cranial computed tomography scan disclosed an acute left superior cerebellar infarction embracing the vermis, and a prior left inferior parietal infarct. Electroencephalogram showed bilateral frontal delta-wave activity. Four weeks later, we performed a technetium-99m hexamethylpropyleneamine oxime single-photon emission computed tomography (Tc-HMPAO SPECT) scan to study the patient's frontal lobe function. The SPECT scan revealed the causative bifrontal hypoperfusion, more prominent on the right, while the structurally evident cerebellar infarction was predictably masked by subacute hyperperfusion phenomenon. Contralateral frontal diaschisis is an established sequela of cerebellar infarction. Because this patient also had lesions in the left parietal region, her left prefrontal area was critically deprived of its major reciprocally connected cortical counterparts (right prefrontal and left parietal), and also became dysfunctional. Her resulting bilateral frontal dysfunction is a common cause of akinetic mutism.

Abstract WP161: Improvement in Cerebral Hemodynamic Parameters and outcomes after Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients with Severe Steno-occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective —Older as well as the recent extracranial-intracranial (EC/IC) bypass trial in patients with symptomatic carotid occlusion failed to demonstrate reduction in stroke recurrence. However, the role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated the changes in various hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) who underwent STA-MCA bypass surgery for impaired cerebral vasodilatory reserve (CVR). Methods —Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged hexamethylpropyleneamine oxime single-photon emission computed tomography (HMPAO-SPECT). STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. TCD and SPECT were repeated in all patients at 4±1 months and they were followed-up for cerebral ischemic events. Results —112 patients (73males, mean age 56yrs; range 23-78yrs) fulfilled our inclusion criteria. HMPAO-SPECT demonstrated impaired CVR in 77 (69%) patients. Forty-six of them underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in STA-MCA bypass group. During follow-up (mean 24 months; range 4 to 33months), only 6/46 (13%) patients in bypass group developed cerebral ischemic events as compared to14/31 (45%) cases on medical therapy (absolute risk reduction 32%, p=0.008). Conclusion —STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in hemodynamic parameters and reduction in stroke recurrence

Usefulness of Dual and Fully Automated Measurements of Cerebral Blood Flow during Balloon Occlusion Test of the Internal Carotid Artery

This study was conducted to show the reliability of fully automated quantification of regional cerebral blood flow (rCBF) in balloon occlusion test (BOT) of the internal carotid artery (ICA). We also shows the usefulness of ratio of rCBF during BOT to rCBF at rest (BOT/rest ratio = rCBF during BOT/rCBF at rest) rather than asymmetry index (AI) during BOT (AI = occluded-side rCBF/contralateral rCBF). In the last 2 years, we performed the BOT on 10 consecutive patients (4 with intracranial aneurysms and 6 with head and neck tumors). During the BOT, mean stump pressure (MSTP) of the ICA was monitored. We measured cerebral blood flow (CBF) with technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography at rest and during BOT. rCBF was determined using 3-dimensional stereotaxic region of interest template (3DSRT) which automatically divided CBF into 12 segments. We defined hypoperfusion segment as BOT/rest ratio <0.9 or AI <0.9. When the BOT/rest ratio was used as a hypoperfusion parameter, the number of hypoperfusion segments was significantly greater in patients with an MSTP ≤50 mm Hg than in patients with an MSTP >50 mm Hg. However, only AI during BOT did not reflect MSTP significantly. The evaluation of CBF changes in BOT using 3DSRT and the BOT/rest ratio were useful because of objective comparison.

Chronic brainstem ischemia in subclavian steal syndrome

Subclavian steal syndrome is usually an incidental finding and rarely causes vertebrobasilar ischemia. We present a 58-year-old man who, over six months, experienced progressive slowing in both talking and walking. Cervical duplex sonography revealed severe stenosis of the right subclavian artery; fixed retrograde flow was noted in the right vertebral artery on transcranial Doppler. The hyperemia–ischemia cuff test resulted in considerable reduction in flow velocities in both posterior cerebral arteries. We attributed his slowness to chronic vertebrobasilar ischemia and surgical revascularization was performed. His symptoms subsided immediately after surgery. The improved perfusion in the posterior circulation was demonstrated on technetium-99 hexamethylpropyleneamine oxime single photon-emission CT. Early diagnosis and prompt treatment resulted in an improved quality of life.

Frontotemporal dementia presenting as pathological gambling

A 69 year-old woman presented to an interdisciplinary medical group with pathological gambling, and went on to develop disinhibition, loss of empathy, and perseverative, stereotyped and ritualistic behavior. An initial neuropsychological evaluation showed selective impairment on the Iowa Gambling Task similar to that of patients with behavioral variant frontotemporal dementia, despite normal performance on standard neuropsychological tasks. MRI scans showed frontal lobe atrophy, which was consistent with findings on hexamethylpropyleneamine oxime single photon emission CT (HMPAO-SPECT). Physical examination, neuropsychiatric and neuropsychological assessments, MRI brain scan, HMPAO-SPECT. Behavioral variant frontotemporal dementia. Pharmacological treatment with the selective serotonin reuptake inhibitor paroxetine for impulsive behavior and carbamazepine to stabilize mood. The patient and her family also received counseling to advise on behavioral and legal issues.

Cerebral control of bladder storage in patients with detrusor overactivity

To identify the brain areas that control bladder storage by technetium-99m hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) with the Neurological Statistical Image Analysis software (NEUROSTAT) in patients with detrusor overactivity (DO). SPECT scans were performed on 19 patients with DO. Eight patients with normal detrusor function, who had some storage symptoms of the lower urinary tract as the patients with DO, also had a SPECT scan, as controls. All the patients were male and right handed, and were scanned twice under two conditions: resting state and urine withholding state. NEUROSTAT was adopted to analyze the difference in brain--blood perfusion between groups and states. The results were displayed on Z score images at a significance threshold of P value of less than 0.05 with correction for multiple comparisons. No region reached the significant threshold in comparison with patients with DO and normal detrusor function in resting state. Significant increases in tracer activity in the right inferior frontal gyrus and the right middle temporal gyrus during urine withholding state as compared with resting state in patients with normal detrusor function were observed. Among the regions, the right inferior frontal gyrus was distinctly prominent at both Z score and the extent. The regions that were significantly activated in patients with normal detrusor function did not reach a significant threshold during urine withholding in patients with DO. The study indicated that the right inferior frontal gyrus and the right middle temporal gyrus, especially the right inferior frontal gyrus, played a role in the cerebral control of bladder storage, inhibiting the contraction of detrusor in urine storage.

A Review of Ancillary Tests in Evaluating Brain Death

The neurological determination of death (NDD) is primarily considered to be clinical. However, situations may arise where confounding factors make this clinical assessment difficult or impossible. As a result, ancillary tests have been developed in order to aid in the confirmation of brain death. As assessment of neuronal electrical activity; electroencephalography (EEG) is no longer recommended in this determination, tools assessing cerebral perfusion, as reflected by the presence or absence of cerebral blood flow (CBF), are the mainstay of NDD. The preferred ancillary test currently is Hexamethylpropylene amine oxime-single photon emission computed tomography (HMPAO SPECT) radionuclide angiography. When this is not available, or is equivocal, 4-vessel cerebral angiography can be used to determine the presence or absence of intracranial blood flow. However, as cerebral angiography has its own limitations, other techniques are sought by physicians in the Intensive Care and Neuro-intensive Care settings to replace cerebral angiography. In this article, we briefly review the history of diagnosis of brain death, pathophysiologic issues in making this determination, and currently available CBF imaging techniques, discussing each in turn with respect to their utility in the diagnosis of brain death.

Cerebral perfusion after a 2-year remission in major depression

Although patients suffering from major depression respond to antidepressant treatment within several weeks, full reinstatement of premorbid capabilities requires much longer. Nevertheless, most research in major depression seeking the pathophysiological correlates of remission has focused upon the acute post-treatment period. Brain imaging research offers no exception. We have recently shown that cerebral perfusion in depressed patients responding to 6-wk antidepressant medication increases in parieto/cerebellar regions and becomes similar to that of healthy control subjects. We now present technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (99mTc-HMPAO SPECT) data collected from 11 of these patients 2 years in remission. Images were analysed using Statistical Parametric Mapping. After 2 years, perfusion normalization found immediately after treatment was maintained, with further increases in frontal and decreases in parieto/cerebellar regions. These findings suggest that perfusion increases in parieto/cerebellar regions may be involved in acute response to treatment whereas increases in frontal regions may be related to its consolidation.

Possible involvement of the tip of temporal lobe in Landau–Kleffner syndrome

Landau–Kleffner syndrome (LKS) is a childhood disorder of unknown etiology characterized by an acquired aphasia and epilepsy. We have performed comprehensive neurofunctional studies on an 8-year-old girl with typical LKS, with the aim of identifying lesions that may be responsible for her condition. 18F-fluoro- d-glucose (FDG) positron emission computed tomography (PET), 11C-Flumazenil (FMZ) PET, 99mTc- hexamethylpropyleneamine oxime single photon emission computed tomography (SPECT) and magnetoencephalography were performed before and after changes to the patient’s medication led to a clinical improvement. Interictal SPECT showed hypoperfusion in the left frontal, left temporal, and left occipital lobes. 18F-FDG PET demonstrated a decrease in glucose metabolism medially in both temporal lobes and superiorly in the left temporal lobe. 11C-FMZ PET revealed a deficit in benzodiazepine receptor binding at the tip of the left temporal lobe. Magnetoencephalography demonstrated equivalent current dipoles located superiorly in the left temporal lobe. Our results suggest that the tip of the left temporal lobe plays an important role in the pathogenesis of LKS in our patient.

99mTc-HMPAO Brain Perfusion Single-Photon Emission Computed Tomography in Children with Down Syndrome: Relationship to Epilepsy, Thyroid Functions, and Congenital Heart Disease

In recent years, it has been possible for patients with Down syndrome to live longer with advanced medical treatment and social support. As a result, the problems of these patients, such as thyroid diseases, leukemia, and Alzheimer disease, would be encountered more frequently. In this study, we aimed to perform the brain perfusion of children with Down syndrome by technetium 99m hexamethylpropylene amine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) and to determine the relationship between brain perfusion and epilepsy, thyroid function tests, congenital heart disease, and level of mental and motor development. Thirty patients with Down syndrome, aged between 1 and 15 years, were included in our study. Demographic data, the existence of epilepsy and congenital heart defects, the level of mental and motor development, serum levels of thyroid hormones, and autoantibodies were determined. All patients underwent computed tomography (CT) and/or magnetic resonance imaging (MRI). Cerebral SPECT was performed in all cases to evaluate the brain perfusion pattern. According to the visual evaluation of cerebral SPECT results, hypoperfusion was detected in 11 cases (37%). Patients with cerebral hypoperfusion (group 1) and patients with normal cerebral perfusion (group 2) were compared. There was no difference between group 1 and group 2 in terms of demographic data, congenital heart defects, IQ levels, thyroid hormones, and autoantibodies, but the incidence of epilepsy was significantly higher in group 1 (P<.001). When motor and mental development levels were compared, it was found that cases in group 1 were significantly more retarded in personal-social and fine motor skills (P<.05). The present study showed that cerebral hypoperfusion in children with Down syndrome is mostly related to epilepsy and the other coexisting conditions, congenital heart disease and hypothyroidism. Patients with cerebral hypoperfusion also have more retarded developmental levels, especially in personal-social and fine motor skills.