Archief Roodbont

Patients with Alzheimer disease (AD) often exhibit vascular changes in the brain. In this study, U.K. researchers used transcranial Doppler ultrasonography of the middle cerebral artery to determine the prevalence of spontaneous cerebral emboli in 84 patients with AD and 60 patients with vascular dementia. Transcranial Doppler ultrasonography was performed every 6 months for 18 months, and changes in cognition, behavior, and functional status were tracked by standardized assessment tools over a 2-year period.

Spontaneous cerebral emboli were detected in 43% of patients with AD and 45% of those with vascular dementia. Scores on every assessment scale showed greater deterioration in patients with emboli than in those without, and the effect of emboli on progression of dementia was similar in patients with AD and those with vascular dementia. Mean decline on the 30-point Mini-Mental State Examination was 6.9 points in emboli-positive patients and 3.4 points in emboli-negative patients; mean change on the 70-point Alzheimer Disease Assessment Scale-Cognitive was 15.4 and 6.0 points, respectively. Few AD patients had internal carotid stenosis or previous strokes.

Comment: These provocative results suggest that vascular disease — as reflected by Doppler-detected asymptomatic cerebral emboli — is a factor in the progression of AD. In fact, an editorialist believes that the dichotomy between AD and vascular dementia has been overstated. The next steps are to figure out the source of these emboli and to determine whether therapies directed against atheromatous disease and thrombosis can slow the progression of AD; unfortunately, a recent study found statin therapy to be ineffective in this regard (JW Gen Med Aug 30 2011).

— Allan S. Brett, MD

Published in Journal Watch General Medicine April 5, 2012