Cholinergic dysfunction in vascular dementia.

Vascular dementia (VaD) is the second most common type of dementia in the elderly after Alzheimer's disease (AD). Evidence is presented indicating the occurrence of cholinergic dysfunction in VaD, independent from AD. Controlled clinical trials of cholinesterase inhibitors (ChEIs) in VaD and in patients with AD plus cerebrovascular disease are reviewed. Compared with placebo, ChEI treatment improves cognition, behavior, and activities of daily living. Cholinergic deficits in patients with VaD may result from ischemia of basal forebrain cholinergic nuclei that are irrigated by penetrating arteries that are highly susceptible to arterial hypertension, or from ischemic lesions in basal ganglia or white matter that sever the extensive cholinergic cortical projections. Cholinergic stimulation produces increases in cortical cerebral blood flow that may be relevant to the therapeutic effect of ChEIs.