Effects of medical and surgical treatment on cerebral perfusion and cognition in patients with chronic cerebral ischemia. The effects of medical treatment with and without cerebral revascularization procedures on cognition and cerebral blood flow were compared among 36 patients with extracranial occlusive cerebrovascular disease and cognitive impairments. Three comparable groups were studied. The first group (N = 18) received only medical treatment by control of risk factors for stroke (including hypertension, diabetes, and hyperlipidemia) and antiplatelet aggregant medication. The second group (N = 10) had the same medical treatment plus superficial temporal-to-middle cerebral artery bypass, and the third group had the same medical treatment plus carotid endarterectomy. Regional cerebral blood flow and cognition were monitored in all three treatment groups over a 3-year interval. All groups showed stabilization without expected rates of decline for both cerebral blood flow and cognition, but no statistically significant differences emerged among the treatment groups. 