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Introduction: Longitudinal studies have reported that patients with idiopathic rapid eye movement sleep behavior disorder (IRBD) have an increased risk of developing synucleinopathies, such as Parkinson's disease and dementia with Lewy bodies (DLB). Clinical trials of disease-modifying therapies for IRBD patients require suitable biomarkers that can predict the short-term onset of neurodegenerative dementia. Methods: We retrospectively examined if easy Z-score imaging system-specific volume-of-interest analysis (SVA) using brain perfusion single-photon emission computed tomography (SPECT) imaging or the cingulate island sign score can predict the short-term development of neurodegenerative dementia in 30 patients with IRBD. Results: Ten patients (33.3%) who exceeded the thresholds for three indicators (severity, extent, and ratio) were included in an SVA-positive group, while 20 (66.7%) were included in an SVA-negative group. Nine (30.0%) IRBD patients had phenoconversion, of which eight had DLB and one had Parkinson's disease with dementia. In Kaplan-Meier analysis, patients in the SVA-positive group converted to neurodegenerative dementia in a significantly shorter period of time compared to patients in the SVA-negative group. Conclusions: These data suggest that SVA-positive IRBD patients have an increased short-term risk of developing neurodegenerative dementia. [ABSTRACT FROM AUTHOR]

Background: This study examined regional cerebral blood flow (rCBF) in Alzheimer's disease (AD) patients with and without subclinical hypothyroidism (SCH). Methods: Eleven AD patients with SCH and 141 AD patients without SCH underwent brain perfusion single photon emission computed tomography (SPECT). The SPECT data were analyzed by statistical parametric mapping (SPM8) and FineSRT. Results: AD patients with SCH showed a significantly decreased rCBF mainly in the temporal lobe and thalamus, whereas those without SCH showed a significantly decreased rCBF in the parietotemporal lobe and cingulate gyrus as well as the frontal lobe. Conclusion: Our findings suggest that SCH may affect cerebral perfusion in regions associated with the memory function. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Introduction: Although anxiety symptoms are often observed in Alzheimer's disease (AD), little attention has been paid to this symptom compared with other neuropsychiatric symptoms. Methods: Twenty-six patients with mild AD underwent both magnetic resonance imaging and single photon emission tomography with technetium-99m ethyl cysteinate dimer. Neuropsychiatric symptoms were evaluated using the Behavioral Pathology in Alzheimer's Disease Scale (Behave-AD). We investigated the relationship between anxiety and neuroimaging using Statistical Parametric Mapping 8 software. Results: The Behave-AD anxiety score was correlated with hyperperfusion in the bilateral anterior cingulate cortices and a reduction in the gray matter volume in the right precuneus and inferior parietal lobule. Conclusion: Our results suggest that anxiety in AD could overlap with the neural correlates of anxiety disorders, and that the specific degeneration associated with AD might be associated with anxiety. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: This study examined the effect of white matter lesions (WMLs) on regional cerebral blood flow (rCBF) in patients with Alzheimer's disease (AD). Methods: Ninety-eight patients with AD were included in the study (40 men and 58 women; mean age, 78.1 years). Cognitive function was assessed using the Mini-Mental State Examination. Brain magnetic resonance imaging (MRI) and 99mTc ethyl cysteinate dimer single photon emission computed tomography were performed in all subjects. AD patients were divided into two subgroups according to the presence of WMLs on MRI. A voxel-by-voxel group analysis using Statistical Parametric Mapping 8 was used to detect the differences in rCBF between the two groups. Results: Fifty-seven of 98 AD patients (58%) showed mild to moderate WMLs on MRI. The prevalence of hypertension was significantly higher in AD patients with WMLs than in those without WMLs. AD patients with WMLs exhibited a significantly decreased rCBF in the anterior cingulate gyrus and insula, compared to AD patients without WMLs. Conclusion: We suggest that WMLs might influence brain regions associated with the limbic system in patients with AD. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to investigate the specific cerebral blood flow (CBF) pattern in patients with idiopathic normal-pressure hydrocephalus (iNPH) and a predictive value for shunt responsiveness in a multicenter study (Study of Idiopathic Normal-Pressure Hydrocephalus on Neurological Improvement: SINPHONI). Methods: Eighty-four iNPH patients underwent shunt operations using MRI selection criteria from the SINPHONI and were subjected to CBF single photon emission computed tomography (SPECT). The perfusion patterns on SPECT were classified: anterior-dominant CBF reduction type (A type), posterior-dominant CBF reduction type (P type), and mixed or diffuse CBF reduction type (M type). The predictive value of the CBF pattern for favorable shunt outcome was evaluated. Results: Favorable outcomes were obtained in 76% (64/84) of patients, and shunt responsiveness was achieved in 85% (71/84) of patients. Areas of severely reduced relative CBF were demonstrated around the corpus callosum and in the sylvian fissure area, which included the effects of dilatations of the ventricles and sylvian fissures and relatively increased perfusion in the medial and lateral frontal, parietal, and occipital areas at high convexity. Forty-nine (58%) cases were A type, 25 (30%) cases were M type, and 10 (12%) cases were P type. A, M, and P type cases exhibited 83, 84, and 90% positive predictive values for shunt responsiveness, respectively. Mean modified Rankin scale and Mini-Mental State Examination scores of the A type group were significantly better than those of other groups. Conclusion: The iNPH patients showed various patterns of CBF reduction, but there was no significant difference in the predictive value among the three patterns, though CBF reduction patterns may suggest a severe condition of iNPH. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]