Abstract
Both spontaneous and traumatic intracranial haemorrhage (ICH) are associated with increased intracranial pressure (ICP) and ultimately with ischaemic brain damage. In patients who have died from subarachnoid haemorrhage Crompton (1964) reported ischaemic brain damage in 70% of autopsies, while Graham et al. (1978) reported a 91% incidence in patients dying after head injury. Although the late manifestations of ischaemic brain damage are common and well documented, the possibility of preventing brain damage depends upon an increased understanding of the early relationships between the bleed, ICP, cerebral blood flow (CBF) and the factors responsible for ischaemia. The objective of the present studies was to determine whether or not the primary damage to the brain was a reduction in CBF, and if so to determine the mechanism of its production.