Inverse relation between Braak stage and cerebrovascular pathology in Alzheimer predominant dementia

The most common neuropathological substrates of dementia are Alzheimer's di sease, cerebrovascular disease, and dementia with Lewy bodies. A preliminar y, retrospective postmortem analysis was performed of the relative burden o f each pathology in 25 patients with predominantly Alzheimer's disease-type dementia. Log Linear modelling was used to assess the relations between Ap oE genotype, Alzheimer's disease, and cerebrovascular disease pathology sco res. Sixteen of 18 cases (89%) with a Braak neuritic pathology score less t han or equal to 4 had, in addition, significant cerebrovascular disease, or dementia with Lewy bodies, or both. There was a significant inverse relati on between cerebrovascular disease and Braak stage (p=0.015). The frequency of the ApoE-epsilon 4 allele was 36.4%. No evidence was found for an assoc iation between possession of the ApoE-epsilon 4 allele and any one patholog ical variable over another. In this series most brains from patients with d ementia for which Alzheimer's disease is the predominant neuropathological substrate also harboured significant cerebrovascular disease or dementia wi th Lewy bodies. The data suggest that these diseases are perhaps pathogenet ically distinct, yet conspire to produce the dementing phenotype.