Dysexecutive versus amnestic Alzheimer disease subgroups: analysis of demographic, genetic, and vascular factors.

The objective of this study was to compare the demographic and vascular characteristics and APOE genotypes of a dysexecutive subgroup of Alzheimer disease (AD) with an amnestic subgroup of AD early in the disease course. A total of 2224 participants from the National Alzheimer's Coordinating Center database who carried a diagnosis of mild cognitive impairment (n=1188) or mild AD (clinical dementia rating ≤1) (n=1036) were included in this study. A subset of the mild cognitive impairment (n=61) and mild AD (n=79) participants underwent an autopsy. A dysexecutive subgroup (n=587) was defined as having executive performance >1 SD worse than memory performance, and an amnestic subgroup (n=549) was defined conversely. Among the autopsy subset, the odds of an AD pathologic diagnosis were compared in the 2 subgroups. The demographics, APOE[Latin Small Letter Open E]4 status, and vascular risk factors were compared in the 2 subgroups. Among the autopsy subset, the odds of having an AD pathologic diagnosis did not differ between the dysexecutive and amnestic subgroups. Under an additive model, participants in the dysexecutive subgroup possessed the APOE[Latin Small Letter Open E]4 allele less frequently compared with those in the amnestic subgroup. The dysexecutive subgroup had a history of hypertension less frequently compared with the amnestic subgroup. These distinct characteristics add to accumulating evidence that a dysexecutive subgroup of AD may have a unique underlying pathophysiology.