Cerebral Metabolic Dysfunction in Patients with Dementia with Lewy Bodies and Visual Hallucinations

Abstract

Aims: To identify the pattern of cerebral hypometabolism in patients with dementia with Lewy bodies (DLB) and visual hallucinations (VH). Methods: Fourteen patients with DLB and VH, 7 with DLB without VH and 16 healthy controls underwent clinical and ¹⁸F-FDG PET evaluations. The 2 patient groups did not significantly differ in their clinical characteristics, except in the occurrence of VH. A voxel-wise comparison of ¹⁸F-FDG PET scans was conducted between each of the 2 patient groups and the control group, and the patient groups among each other. Results: Compared with the control group, hypometabolic regions were more extensive and confluent in the patient group with VH than in the group without VH. The direct comparison between the 2 patient groups revealed a significant metabolic deficit in the group with VH at the right occipito-temporal junction and the right middle frontal gyrus. Conclusions: These results suggest that hypometabolism in visual association areas rather than the primary visual cortex is involved in VH in DLB.