Value of transcranial Doppler examination in the diagnosis of cerebral vasospasm after subarachnoid hemorrhage.

Abstract

In 21 patients with subarachnoid hemorrhage secondary to ruptured intracranial aneurysms, we performed serial neurological evaluations, transcranial Doppler examinations, and cerebral blood flow (CBF) determinations. We classified 8 patients as having vasospasm (delayed neurological deterioration, appropriate reduction of CBF) and 13 patients as having no spasm on the basis of this information. Transcranial Doppler flow velocities in the middle cerebral artery and the anterior cerebral artery were significantly elevated for the group with vasospasm on posthemorrhage Days 4 through 12. Elevation of transcranial Doppler velocities preceded clinical signs of cerebral ischemia. The maximal transcranial Doppler flow velocities achieved were compared on the basis of the extent of clot on early computed tomographic (CT) scans. The mean anterior cerebral artery flow velocities were significantly different between CT Grades II and III. The initial transcranial Doppler flow velocities were compared on the basis of the patient's Hunt and Hess grade upon admission. The flow velocities for Grade V patients were significantly lower than those for Grade IV patients. Transcranial Doppler flow velocities were compared with arteriographically observed anterior cerebral artery and middle cerebral artery radii in 12 instances. The correlation was poor, but the data should be interpreted cautiously in view of the small number of arteriograms. We conclude that transcranial Doppler examination has considerable potential in the early diagnosis of delayed ischemic neurological deficit (clinical vasospasm) in patients with subarachnoid hemorrhage.