PROSPECTIVE STUDIES OF CEREBRAL PERFUSION AND COGNITIVE TESTING AMONGELDERLY NORMAL VOLUNTEERS AND PATIENTS WITH ISCHEMIC VASCULAR DEMENTIA AND ALZHEIMERS-DISEASE

To compare longitudinal changes of cerebral perfusion (CBF) and cognit ive status in two common forms of dementia in the elderly, 42 patients with ischemic vascular dementia (IVD), 44 patients with dementia of t he Alzheimer type (DAT), and 120 elderly normal volunteers were evalua ted prospectively over a mean interval of 3.35 years. Subjects were at least age sixty, (mean age 71.1). Mean bihemispheric cerebral blood f low and cognitive test scores of control subjects were significantly h igher than those of both demented groups at entry and remained so. Aft er adjustment for initial CBF, course over time was similar for all gr oups. Group variability was similar for CBF but not for cognition. Bot h IVD and DAT patients were more variable than controls but similar to each other. Throughout, DAT patients showed greater cognitive impairm ents than IVD patients. Cognitive impairments stabilized among IVD pat ients treated by control of risk factors, antiplatelet or anticoagulan t therapy but declined progressively among DAT patients.