Experimental Study of Chronic Cerebral Spasm

For the purpose of the study of severity of the chronic vasospasm after subarachnoud hemorrhage(SAH), SAH was induced in dogs by injections of fresh unheparinized autologous arterial blood into the cisterna magna. The experimental groups were devided into two groups. Group I was that of the only one 5ml injection of subarachnoid blood, and Group II was that of the double-hemorrhage canine model; secondary injection of 3ml at 24hours after initial injection. Selective left vertebral angiograms were performed 5 days before and 7 days after the initial SAH and were compared to determine the percentage of reduction in basilar artery diameters. The reductions in basilar artery diameter of Group I and II were 33.0%±0.90 and 45.3%±1.99 respectively.

This result suggest that the severity of spasm is related to the volume of hemorrhage and rebleeding episode.