Value of Transcranial Doppler Ultrasonography in the Diagnosis and Management of Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage

Abstract 788 Background: Transcranial Doppler (TCD) is routinely used to diagnose cerebral vasospasm after subarachnoid hemorrhage (SAH). Its reliability in individual patients remains unestablished. We correlated TCD velocities with angiographic vasospasm (AV) to determine its predictive value in a given patient. Methods: Aneurysmal subarachnoid hemorrhage patients between 1/94 and 5/97 were retrospectively reviewed. AV on follow-up angiograms was independently graded as none, mild (<⅓ narrowing), moderate (⅓-½ narrowing), or severe (>½ narrowing) by 2 blinded observers. Middle cerebral artery velocities obtained within 1 day of the angiogram were correlated with AV. Results: One hundred one patients were included. Interobserver agreement for AV was good (kappa, 0.86). The predictive/negative predictive values (considering moderate/severe AV as significant) for various velocity ranges were as follows: ≤ 120, 0.55/0.94*; 120 to 159, 0.44/0.77; 160 to 199, 0.56/0.75; ≥ 200, 0.87*/0.77. The likelihood ratios for <120 and ≥ 200 ranges were 0.17...