Patterns of gray matter atrophy in dementia with Lewy bodies: a voxel-based morphometry study

Abstract

Background: Dementia with Lewy bodies (DLB) is a common form of dementia characterized by visual hallucinations, cognitive fluctuation and parkinsonism. We aimed to compare the patterns of gray matter atrophy in DLB with those in Alzheimer's disease (AD) and normal aging, and to investigate the relationship between atrophy and cognitive measures.

Methods: We used voxel-based morphometry (VBM) to investigate gray matter (GM) loss in DLB (n = 35; mean age = 78.4; MMSE = 20.3), AD (n = 36; mean age = 78.3; MMSE = 19.5) and similar aged controls (n = 35; mean age = 76.7; MMSE = 29.1). T1 weighted MRI scans were acquired at 3 Tesla from all subjects and analyzed using VBM-DARTEL in SPM8. Cognitive function was assessed using the Cambridge Cognitive Examination (CAMCOG).

Results: We found reduced gray matter in temporal, parietal, occipital, and subcortical structures in DLB when compared to normal controls. The degree of atrophy was less than that observed in AD. There was significantly more medial temporal lobe atrophy in the AD group when compared with DLB. We did not find a correlation between total CAMCOG score and atrophy, but the CAMCOG memory subscale score correlated with temporal lobe atrophy in both the DLB and combined DLB/AD group.

Conclusions: DLB is associated with less gray matter atrophy and relative preservation of the medial temporal lobe when compared to AD. Degree of medial temporal atrophy may be a useful imaging biomarker and our results provide support for its inclusion in the revised consensus criteria for DLB.