Vertebrobasilar spasm: a significant cause of neurological deficit in head injury.

Cerebral vasospasm in the anterior circulation has been recognized as a significant factor in the sequelae of head injury; however, vertebrobasilar spasm resulting from trauma has received much less attention. In the past year we have observed six patients where spasm in the major vessels of the posterior circulation was primarily or in part responsible for the neurological deficit. In such cases, the neurological examination may suggest a supratentorial mass with herniation and, in three of our cases, burr holes or carotid angiography were performed first. However, in every instance neurological signs present on admission indicated primary brain-stem dysfunction. In each of the six cases vertebral angiography demonstrated significant spasm in either the vertebral or basilar arteries. Intracranial pressure was monitored in each of the six patients and did not exceed 25 mm Hg in any. In cases of head injury where the neurological examination indicates brain-stem dysfunction inconsistent with or after a supratentorial mass has been excluded, vertebral angiography may aid in the diagnosis and subsequent management of such patients.