Cerebrovascular Reactivity Related to Focal Brain Edema in the Primate

Unilateral cold injury was produced in 11 baboons. Regional cerebral white matter blood flow was measured 30 h later together with the response to arterial hypotension, hypertension, and hypercapnia. Flow was lowest in the areas of edema, fell during hypotension but did not increase with hypertension; the CO2 response was impaired. In four baboons which had an injury but did not have edema, normotensive CBF and the CO2 response were both normal but autoregulation was impaired to both hypo- and hypertension. In the white matter opposite to the area of edema even though water and sodium content in this part of the brain was normal, CBF was reduced, fell with hypotension, had a smaller than normal CO2 response, but did not increase during arterial hypertension.