Significant amyloid-beta (Abeta) deposition in cases of dementia with Lewy bodies (DLB) may represent concurrent Alzheimer's disease (AD). To test this hypothesis, the laminar distribution of the diffuse, primitive, and classic Abeta deposits was studied in the frontal and temporal cortex in cases of DLB and were compared with AD. In DLB, the diffuse and primitive deposits exhibited two common patterns of distribution; either maximum density occurred in the upper cortical laminae or a bimodal distribution was present with density peaks in the upper and lower laminae. In addition, a bimodal distribution of the classic deposits was observed in approximately half of the cortical areas analysed. A number of differences in the laminar distributions of Abeta deposits were observed in DLB and AD. First, the proportion of the primitive relative to the diffuse and classic deposits present was lower in DLB compared with AD. Second, the primitive deposits were more frequently bimodally distributed in DLB. Third, the density of the diffuse deposits reached a maximum lower in the cortical profile in AD. These data suggest differences in the pattern of cortical degeneration in the two disorders and therefore, DLB cases with significant Abeta pathology may not represent the coexistence of DLB and AD.
|Number of pages||6|
|Publication status||Published - 2002|
- Alzheimer's disease
- Amyloid-beta (Abeta) deposits
- cortico-cortical pathways
- dementia with Lewy bodies
- laminar distribution