MEDIAL TEMPORAL AND WHOLE-BRAIN ATROPHY IN DEMENTIA WITH LEWY BODIES - A VOLUMETRIC MRI STUDY

Objective: Dementia with Lewy bodies (DLB) is emerging as a common cau se of degenerative dementia. A recent pathologic study has indicated t hat the medial temporal lobe in patients with DLB was less atrophic th an that in patients with AD. The purpose of this study was to examine whether medial temporal MRI volumetry was useful to differentiate DLB from AD clinically. Methods: We compared the volumes of the hippocampa l formation, amygdaloid complex, and whole brain in 27 patients with p robable DLB (based on the criteria of the Consortium on DLB Internatio nal Workshop), 27 patients with probable AD (based on criteria of the National Institute of Neurological Disease and Stroke/Alzheimer's Dise ase and Related Disorders Association), and 27 normal elderly subjects using an MRI-based volumetric technique. The three groups were matche d for age and sex. Severity of cognitive disturbances represented by t heir Mini-Mental State Examination score was comparable between the DL B and AD groups. Results: Hippocampal volume (normalized to intracrani al volume) in the DLB group was significantly larger than that in the AD group, but significantly smaller than that in the normal control gr oup, There were no significant differences in the amygdala and whole-b rain volume between the DLB group and the AD group, but, the atrophies of the amygdala and whole brain were more severe in the DLB group tha n those in the control group, Conclusions: These findings indicate the usefulness of MRI hippocampal volumetry in clinically discriminating patients with DLB from patients with AD.