Alterations in membrane function may occur as a consequence of aging because of a decrease in the synthesis or an increase in the catabolism of choline and ethanolamine glycerophospholipids, leading to impairment in cognitive function. Experimental studies have shown that the administration of CDP-choline increases the total amount of phosphatidylcholine and other related phospholipids in the brain and in some cases may enhance neurotransmission. Clinical assessments and neuropsychologic tests in patients with cerebral insufficiency, chronic cerebrovascular disease, and dementia suggest that CDP-choline may improve some of the memory deficits associated with aging.