Dementia with Lewy bodies and Alzheimer's disease

To investigate similarities and differences between Alzheimer's disease (AD ) and dementia with Lewy bodies (DLB), we undertook a demographic analysis of 277 patients from the Kathleen Price Bryan Brain Bank with an antemortem diagnosis of probable AD. Patients with additional, possibly confounding c linical and pathologic diagnoses such as infarcts, hematomas, neoplasms, an d other neurodegenerative disorders, were excluded from the analysis. Neuro pathologically, AD alone was present in 192 subjects (69%), and DLB was fou nd in 85 subjects (31%). All of the DLB cases had neuropathologic evidence of AD sufficient to meet CERAD criteria for a diagnosis of definite AD plus nigral Lewy bodies. Gender, apolipoprotein E (APOE) genotype, brain weight , age at death, duration of disease and Braak stage were compared between t he two groups. Statistical analyses were performed using Fisher's exact tes t for comparisons of categorical data and Student's t-test for comparison o f means for continuous outcomes. The proportion of males and females was ba lanced in the combined AD and DLB populations. There was a highly statistic ally significant increased frequency of APOE 3/4 in males with DLB (P=0.007 ). We found higher brain weights in males with DLB versus males with AD (P= 0.012). AD was more frequent in females and DLB was more frequent in males (P=0.019). Our findings with respect to age at death, duration of disease a nd Braak stage within diagnostic groups confirm previously reported finding s. These data suggest that Lewy bodies are more common in males affected wi th dementia, especially those with the APOE 3/4 genotype.