Local cerebral blood flow mapping before and after removal of acute subdural hematoma in the rat.

The cause of hemispheric swelling and high intracranial pressure after acute subdural hematoma is unknown, yet this is a major cause of death related to this condition. To investigate whether vascular engorgement is the cause of this form of hemisphere swelling, we have autoradiographically mapped regional cerebral blood flow before and after removal of acute subdural hematoma in a rat model. Hyperemia was patchy and infrequent. The major cause of the significant hemisphere swelling seen after hematoma removal was enlargement of the zone of focal tissue ischemia and edema under the hematoma.