Abstract
Devices to produce experimental subarachnoid hemorrhage (SAH) can be implanted in animals. After SAH is produced by the puncture of a middle cerebral artery (MCA) in awake cats, neurologic deficits develop that are not as severe as those caused by MCA occlusion. Biphasic increases of epidural pressure occur and are related to the extent and distribution of the hemorrhage. Ischemic changes are more severe if the flow of blood through the MCA is interrupted.