The utility of measuring the corpus callosal angle (CA) for the diagnosis of idiopathic normal pressure hydrocephalus (INPH) was investigated. Three-dimensional magnetic resonance imaging (MRI) was performed in 34 INPH patients, 34 Alzheimer's disease (AD) patients, and 34 normal control (NC) subjects. Measurement of the CA on the coronal MR images of the posterior commissure perpendicular to the anteroposterior commissure plane was performed for all subjects. The CA of the INPH group (mean +/- SD, 66 +/- 14 degrees) was significantly smaller than those of the AD (104 +/- 15 degrees) and NC (112 +/- 11 degrees) groups. When using the threshold of the mean - 2SD value of the NC group (= 90 degrees), an accuracy of 93%, sensitivity of 97%, and specificity of 88% were observed for discrimination of INPH from AD patients. Measuring the CA helps in differentiating INPH patients from AD and normally aged subjects.

Aims: To investigate regional morphologic changes in idiopathic normal pressure hydrocephalus (INPH) based on diagnosis with INPH Guidelines using voxel-based morphometry. Method: Three-dimensional magnetic resonance imaging was performed in 34 INPH patients, who met probable INPH criteria, probable 34 Alzheimer disease patients, and 34 normal control subjects. Results: Statistical parametric mapping was used to conduct voxel-based morphometry analysis of the morphologic data and revealed enlarged ventricles and sylvian fissures and stenotic sulci of high convexity, especially in the precuneus in the INPH group, with decreased gray matter density in the insula, caudate and thalamus. Conclusion: In INPH, morphologic change occurs in the frontoparietal high convexity with ventricular dilatations, dilated sylvian fissures and tight sulci in the medial parietal lobes.

The aim of this study was to investigate regional differences between morphologic and functional changes in patients with mild dementia with Lewy bodies (DLB) compared with those with Alzheimer's disease (AD). Methods: Twenty patients with very mild DLB (mean age, 74.5 y; mean Mini-Mental State Examination [MMSE] score, 24.0), 20 patients with very mild AD (mean age, 74.1 y; mean MMSE score, 24.0), and 20 age-and sex-matched healthy volunteers (normal controls [NC]) underwent both 18 F-FDG PET and 3-dimensional spoiled gradient echo MRI. Fully automatic volumetry of the MRI data was used to obtain whole brain, hippocampal, occipital, and striatal volumes, which were compared with the results of a similar analysis of glucose metabolic data. Results: In DLB patients, volumetric data indicated a significant volume decrease in the striatum, whereas 18 F-FDG PET showed significant glucose metabolic reductions in the temporal, parietal, and frontal areas-including in the occipital lobe-compared with those in the NC group. In contrast, in AD patients, both the hippocampal volume and glucose metabolism were significantly decreased, whereas the occipital volume and metabolism were preserved. Conclusion: Comparison of very mild DLB and AD revealed different morphologic and metabolic changes occurring in the medial temporal lobes and the occipital lobe, demonstrating characteristic pathophysiologic differences between these 2 diseases. Dement ia with Lewy bodies (DLB), a clinical entity of primary degenerative dementia pathologically characterized by the presence of Lewy bodies in cortical, subcortical, and brain-stem structures, is the second most common degenerative dementia after Alzheimer's disease (AD). In the DLB brain, the occipital lobe is not affected histopathologically but metabolic or perfusional reduction is present in the occipital lobe (1-3), whereas the medial temporal limbic area is minimally affected histopathologically (4-6). In the mild AD brain, neuropathologic changes predominantly affect the neocortical association area and medial temporal limbic area. These histopathologic changes lead to focal atrophy and can be demonstrated by MRI (7,8), whereas metabolic reductions are demonstrated in the neocortical association area by PET (9,10). However, there has been controversy as to whether medial temporal metabolic reductions exist in the early stage of AD (11-16). The localization method using the region of interest (ROI) showed that significant medial temporal hypometabolism may be seen in AD, even in the incipient amnestic mildcognitive-impairment stage (13-15). These morphologic and functional changes in the same patients have been studied in AD patients (16), although, to our knowledge, there are no reports describing these investigations in the same DLB patients.By analyzing both MR images and glucose metabolic PET in patients with mild DLB or AD in this study-using automatic volumetric and voxel-based techniques for MR images and metabolic values of regional structures and the voxel-based techniq...

In FTD, metabolic and morphologic changes occur in the bilateral frontal lobe and temporal lobe with a limited asymmetry whereas there was considerable discordance in the AD group.

BACKGROUND AND PURPOSE: DLB is recognized as the second major form of dementia in the elderly. The regional pattern of GM atrophy in DLB highly overlaps that in AD. The aim of this study was to identify the critical pattern of atrophy in DLB by using DARTEL, which provides improved registration accuracy compared with that of conventional VBM.