Treatment of cerebral ischemia--where are we headed.

THE PAST DECADE has witnessed an explosion of technological advances in neuroimaging and neurochemistry. Measurement of cerebral blood flow and metabolism, and radiographic and sonographic imaging of the brain and the extracranial cerebral vasculature are now far more advanced. Hematologjsts and experimental pathologists have begun to classify the complexities of blood coagulation and its interrelationships with atherosclerotic and other vascular lesions. We can now begin to approach the laboratory stroke model and diagnostic problems of the human stroke patient more logically and completely. Also newer stroke treatments have been developed e.g. extracranial to intracranial bypass procedures and newer "antiplatelet" drugs. These advances have given the present day clinician a more potent and complex armamentarium. With the increased complexity comes a clearer need for a strategy or a road map to plan future controlled therapeutic trials, or simply to treat the individual stroke patient in the clinic. In a prior communication,1 I had argued why therapeutic decisions based solely on a simple classification of patients that considered only the time course of deficit (TIA, RIND, progressing stroke, or completed stroke) were irrational and impractical. I will in this note share some thoughts on the positive side, that is, how we should be planning future treatment and trials. There are 5 important factors that, to a large extent, determine short term and long range prognosis in patients with cerebral ischemia: 1) location and severity of the causative vascular lesion, 2) hematological state, 3) size, location and reversibility of brain ischemia, 4) intercurrent medical illness and complications of the stroke or its treatment, and 5) psycho-socioeconomic factors. The latter two items which concern the general medical and social health of the patient are of course important factors in any illness and are not unique to stroke. The treating physician always must decide if serious medical illness, or non-medical sociological considerations will limit treatment alternatives. Severe dementia prior to stroke, serious incapacitating cardiac disease, or terminal cancer will clearly limit some therapies as will a patient who is noncompliant,