Intra-Arterial Dantrolene for Refractory Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND: Dantrolene has a safe side-effect profile and a mechanism of action that makes it attractive as an option for treatment of cerebral vasospasm. The authors report 2 cases of refractory cerebral vasospasm secondary to aneurysmal subarachnoid hemorrhage that were successfully treated with intra-arterial (IA) dantrolene. CASE DESCRIPTION: Two patients, a 63-year-old woman and 36-year-old woman, developed severe vasospasm refractory to IA vasodilators after rupture of anterior communicating artery aneurysms. IA dantrolene was injected in doses of 15-30 mg in the affected distributions and mean arterial pressure, intracranial pressure, and heart rate were monitored. There was immediate improvement in lumen diameter of the affected vessels following dantrolene injection. No significant differences in mean arterial pressure or intracranial pressure before and after IA dantrolene were observed. Both patients demonstrated clinical improvement within 24 hours without any further deterioration during the rest of their admission. Follow-up angiography 48 hours after IA dantrolene treatment demonstrated continued resolution of cerebral vasospasm. CONCLUSIONS: This evidence suggests IA dantrolene as a safe and effective novel alternative for the treatment of cerebral vasospasm.