[Atraumatic measurement of cerebral blood flow in spontaneous meningeal hemorrhage].

Cerebral blood flow (CBF) was measured 74 times in 50 patients with spontaneous meningeal hemorrhage using a method involving the inhalation of Xenon-133. The procedure is non-invasive, reproductible, and provides reliable results. Correlation was found between the clinical state and the CBF, but very low mean values for CBF, and ischemic foci associated with these values, were detected in cases where this could not be predicted from the clinical findings. No correlation existed between vasospasm seen on angiography and the ischemic foci revealed by the isotopic method. The age of patients had an influence on CBF values but not on the clinical course. Mean CBF levels during the first two weeks of the disease were significantly higher in patients in whom the course was uncomplicated, whatever their clinical condition (excluding coma) at the time of CBF measurement. A figure of 60 ml/100 g/min for gray substance blood flow appeared to be a threshold value, below which there was a greater risk of complications. Inversely, the outcome was favorable in all cases with a cortical blood flow superior to 70 ml. These findings suggest that cerebral blood flow measurement provides prognostic information which could be of marked assistance when deciding on appropriate therapy in such cases.