Cerebral circulation after head injury

Abstract

✓ Measurements of cerebral blood flow (CBF), mean intraventricular pressure (MIVP), CSF acid-base status, and tests of autoregulation and CO 2 reactivity of 43 patients were made at varying times after severe closed head injury. There was a distinct hyperemia or “luxury perfusion” in the acute phase of 1 to 14 days, followed by recovery to normal or below normal values. Metabolic CSF acidosis was found with hyperemia and probably reflected severe, diffuse cortical injury. Distinct regional CBF abnormalities, either ischemic or hyperemic, were only observed in regions of focal pathology. Severe ischemia, hyperemia, persistent elevation of MIVP, or generalized “vasoparalysis” indicated an unfavorable prognosis. Autoregulation was impaired and CO 2 reactivity was reduced after injury, but both had usually returned to normal by 14 days.