Changes in cerebral blood flow and recovery from acute stroke.

Abstract

SUMMARYWe prospectively studied 14 patients with acute cerebral infarctions using serial I33 Xenon inhalation cerebral determination ( 133 Xe-rCBF), scored neurological examinations, and neuropsychologicai testing. All patients underwent the same battery of tests at 3 days, 1 week, 2 weeks, and 4 weeks after cerebral infarction to determine the prognostic value of early rCBF studies and the chronological relationship of changes in rCBF to clinical status. Baseline rCBF within 3 days of symptoms of acute stroke did not correlate with clinical neurological outcome (r = -0.17, p < 0.30; r = -0.18, p < 0.28, for the two indices of rCBF used). Among the 11 patients demonstrating neurological recovery, 7 improved at 1 week, significantly before increases in rCBF (p < 0.05). We conclude that early baseline rCBF does not predict dinical outcome in patients with acute cerebral infarctions and that return of neurological function precedes rather than follows increases in rCBF. Stroke Vol 17, No 2, 1986 AS VASCULAR OCCLUSION is the underlying cause of acute cerebral infarction, decreased regional cerebral blood flow (rCBF) would appear to be a predictable occurrence following acute stroke. Several reports indicate early rCBF determinations do correlate with magnitude of infarction and predict clinical outcome. These studies find that luxury perfusion indicates a good prognosis, and low initial rCBF bodes ill for the patient with acute stroke. '~9 As lysis of a thrombus and/or opening of collaterals could be crucial in salvaging ischemic neurons, it seems reasonable that an increase in rCBF would accompany improvement in stroke patients. However, no study has examined the chronological relation between changes in rCBF and clinical changes in patients with acute stroke. In an attempt to assess this relationship and more precisely define the predictive value of early rCBF measurement in patients with acute stroke, we prospectively followed 14 patients with acute hemispheric infarctions by means of serial neurological exams, rCBF determinations, and neuropsychological testing. Methods and MaterialsFourteen patients admitted to the neurology service of the Hospital of the University of Pennsylvania with diagnoses of acute cerebral infarctions involving cere-

Neuropsychology, Neuropsychiatry, and Behavioral Neurology

“…Other studies however, indicate that initial CBF levels are not predictive of clinical outcome (Burke et al, 1986). Thus, blood flow increases only when undamaged neurons return to a functionally active state (Burke et al, 1986) rather than acting to rejuvenate injured tissue. Thus, blood flow increases only when undamaged neurons return to a functionally active state (Burke et al, 1986) rather than acting to rejuvenate injured tissue.…”

Can raising cerebral blood flow improve outcome after acute cerebral infarction?

“…However, quantitative measures of CBF may be disappointingly misleading since they do not correlate with clinical stroke severity 1 or extent of extracranial arterial stenosis. 2 -3 Furthermore, regions of low, normal, or even increased flow can be seen for several days after CI probably because of variability from patient to patient in reperfusion through collateral channels, breakup of emboli, and compensatory vasodilation.…”