Introduction: Cerebral vasospasm is one the most clinically significant sequelae of aneurysmal subarachnoid hemorrhage given its significant effects related to morbidity and mortality in this patient population. Among the treatment options for cerebral vasospasm, dantrolene has been of interest given its well tolerated side effect profile and plausible biological mechanism. We present a case of intra-arterial dantrolene injection for the treatment of refractory vasospasm secondary to rupture of an anterior communicating artery aneurysm.

Methods: A 63 year old female presented to the ER 3 days after the ictus of the "worst headache of her life", nausea and vomiting, and an episode of loss of consciousness for approximately 8 hours. She was a Hunt and Hess grade II and a modified Fisher grade III. She underwent coiling of an anterior communicating artery aneurysm. During the her ICU stay, she developed severe, symptomatic cerebral vasospasm needing four angiographic interventions for intra-arterial calcium blocker injection. During her last intervention, 15 mg of intra-arterial datrolene were injected into the left internal carotid artery over 20 minutes and then the same procedure was performed on the right internal carotid artery. Blood pressure, heart rate and intracranial pressure were recorded.

Results: Post-injection, significant improvement in vasospasm was observed. Mean systolic pressures were 130.36 mmHg, mean diastolic pressures were 74.69 mmHg and mean intracranial pressures were 26.72. Follow-up angiogram two days after the procedure showed sustained resolution of cerebral vasospasm. The patient did not developed cerebral vasospasm again.

Conclusions: Intra-arterial dantrolene was both safe and effective for the treatment of refractory cerebral vasospasm in this patient. Not only did it cause significant improvement in vasospasm, but it also caused sustained resolution two days after the procedure. More studies should be performed to study the role of intra-arterial dantrolene for the treatment of cerebral vasospasm.

Patient Care: Dantrolene is a promising agent for the treatment of cerebral vasospasm. It has a well tolerated side-effect profile and is effective for induction and sustentation of vasodilation after cerebral vasospasm. By studying its effects we may be able to identify a novel agent for the treatment of cerebral vasospasm.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) describe both the Hunt and Hess grade and the Modified Fisher scale and their clinical significance for aneurysmal subarachnoid hemorrhage. 2) discuss the mechanism of action of dantrolene and the basis for its role in cerebral vasospasm treatment 3) discuss a novel case report of the use of intra-arterial dantrolene in a patient with refractory cerebral vasospasm

References: Majidi M, Grigoryan M, Tekle W. and Qureshi A. Intra-arterial Dantrolene for Refractory Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage. Neurocrit Care 92012) 17:245-249.