Intra-Arterial Nicardipine Infusion Improves CT Perfusion-Measured Cerebral Blood Flow in Patients with Subarachnoid Hemorrhage-induced Vasospasm

BACKGROUND AND PURPOSE: Our aim was to determine the effects of intra-arterial (IA) nicardipine infusion on the cerebral hemodynamics of patients with aneurysmal subarachnoid hemorrhage (aSAH)-induced vasospasm by using first-pass quantitative cine CT perfusion (CTP). MATERIALS AND METHODS: Six patients post-aSAH with clinical and transcranial Doppler findings suggestive of vasospasm were evaluated by CT angiography and CTP immediately before angiography for possible vasospasm treatment, CTP was repeated immediately following IA nicardipine infusion. Maps of mean transit time (MITT), cerebral blood volume (CBV), and cerebral blood flow (CBF) were constructed and analyzed in a blinded manner. Corresponding regions of interest on these maps from the bilateral middle cerebral artery territories and, when appropriate, the bilateral anterior or posterior cerebral artery territories, were selected from the pre- and posttreatment scans. Normalized values were compared by repeated measures analysis of variance. RESULTS: Angiographic vasospasm was confirmed in all patients. In 5 of the 6 patients, both CBF and MTT improved significantly in affected regions in response to nicardipine therapy (mean increase in CBF, 41 +/- 43%; range, -9%-162%, P = .0004; mean decrease in MTT, 26 +/- 24%; range, 0%-70%, P = .0002). In I patient, we were unable to quantify improvement in flow parameters due to section-selection differences between the pre- and posttreatment examinations. CONCLUSIONS: IA nicardipine improves CBF and MTT in ischemic regions in patients with aSAH-induced vasospasm. Our data provide a tissue-level complement to the favorable effects of IA nicardipine reported on prior angiographic studies. CTP may provide a surrogate marker for monitoring the success of treatment strategies in patients with aSAH-induced vasospasm.