Associated systemic factors in cerebrovascular ischemia.

Systemic disorders (eg, cardiac, hematologic) are commonly recognized as predisposing and sometimes actual precipitating events in cerebral ischemia. From available studies, the incidence of precipitation is not clear. To determine this, we undertook a comprehensive investigation of all patients with ischemic brain disease for a one-year period. Results reveal that brain ischemia is more commonly precipitated by systemic illness than usually supposed, particularly transient ischemic attacks of the vertebrobasilar circulation and completed infarcts in the carotid distribution. Cardiac disorders outnumber all other precipitating events. As they are more amenable to therapy than atherosclerosis, a diligent search for such precipitating events is warranted in patients with ischemic symptoms.