nrCBF for Timing of Angiography and Operation in Subarachnoid Hemorrhage

Early operation on cerebral aneurysms is demanded not least because of the threat of spasm of the cerebral vessels. As is generally recognized, this is to be expected in a very high percentage within a few days after the first aneurysm hemorrhage and frequently cannot be diagnosed clinically (4, 5). Many neurosurgeons have rated the risk of operating in the presence of vasospasm so high that, like C.G. DRAKE in 1975 (2), they demanded control angiography with its own risk, especially in existing vasospasm in early angiography and the aneurysm operation itself could not take place rapidly.