Differences in Rate of Cognitive Decline and Caregiver Burden between Alzheimer's Disease and Vascular Dementia: a Retrospective Study.

Few studies have explored the rate of cognitive decline and caregiver burden within the context of a specialized memory clinic. When this was done, the focus was largely on functional decline related to Alzheimer's disease (AD). Our goal was to compare the longitudinal decline of AD patients to those with Vascular Dementia (VaD) on Mini-Mental State Examination (MMSE). We further explored the differential impact on caregiver burden. We retrospectively studied 237 charts from patients seen at our Memory Clinic between 2006 and 2012. The data was collected over 17 years. Cohorts were formed by excluding conditions other than AD and VaD, and including patients who had been assessed at least twice with the MMSE (AD: n = 83; mean age: 67.7 yo; VaD: n = 32; mean age: 73.3yo). A small group of 36 caregivers was surveyed by phone to explore caregiver burden. Results indicated that the natural history of MMSE changes in AD patients differed significantly from that of patients with VaD (F = 10.41, p<0.0014), with AD patients showing more cognitive decline over time. Sadness, stress/anxiety, fatigue, and sleep disorders were reported as the main preoccupations by caregivers and its impact was rated as 'severe' in 50% of cases. Altogether, this study provides further insight into the natural history of cognitive decline in AD and VaD. Future studies should explore the progression of dementing disorders in larger cohorts using prospective methodological designs.