The Effect of Cerebral Infarction on the Regional Cerebral Blood Flow of the Contralateral Hemisphere

Abstract

Regional cerebral blood flow (rCBF) measurements were performed over the contralateral hemisphere by the 133 Xe intracarotid injection method in 20 patients with acute cerebral infarction in the territory of the internal carotid artery. The rCBF was found to be reduced, sometimes remarkably, in all of the patients. The mean reduction was 30% to 36% from the lowest normal value for the mean age of these patients. In the younger age group (40 to 59) the reduction was greater, 40% to 47% from the lowest normal value for this age. The rCBF depression was not related to cerebral dominance, previous hypertension or arterial Pco 2 levels. It occurred in both patients who were fully alert and those with disturbances of consciousness, although it tended to be more diminished in the latter. It can be assumed that the flow reduction in the nonaffected hemisphere is part of a general phenomenon affecting the entire brain and caused by globally reduced cerebral metabolism.