Safety and Outcomes of Valproic Acid in Subarachnoid Hemorrhage Patients: A Retrospective Study

Abstract

Background and purpose: Animal studies have suggested that valproic acid (VPA) is neuroprotective in aneurysmal subarachnoid hemorrhage (SAH). Potential mechanisms include an effect on cortical spreading depolarizations (CSD), apoptosis, blood-brain barrier integrity, and inflammatory pathways. However, the effect of VPA on SAH outcomes in humans has not been investigated.

Methods: We conducted a retrospective analysis of 123 patients with nontraumatic SAH. Eighty-seven patients had an aneurysmal source and 36 patients did not have a culprit lesion identified. We used stepwise logistic regression to determine the association between VPA and the following: delayed cerebral ischemia (DCI), radiographic vasospasm, and discharge modified Rankin Scale (mRS) score > 3.

Results: All 18 patients who received VPA underwent coil embolization of their aneurysm. VPA use did not have a significant association with DCI on adjusted analysis (Odds Ratio, OR = 1.07, 95% CI: 0.20 - 5.80). The association between VPA use and vasospasm was OR = 0.64 (0.19 - 1.98) and discharge mRS > 3 was OR = 0.45 (0.10 - 1.64). Increased age (OR = 1.04, 1.01 - 1.07) and Hunt and Hess (HH) grade > 3 (OR = 14.5, 4.31 - 48.6) were associated with an increased likelihood for poor discharge outcome (mRS > 3). Younger age (OR = 0.96, 0.93 - 0.99), mFS score = 4 (OR = 4.14, 1.81 - 9.45), and HH grade > 3 (OR = 2.92, 1.11 - 7.69) were all associated with subsequent development of radiographic vasospasm. There were no complications associated with VPA administration.

Conclusion: We did not observe an association between VPA and the rate of DCI. There may have been a protective association on discharge outcome and radiographic vasospasm that did not reach statistical significance. We found that VPA use was safe and is plausible to be used in a population of SAH patients who have undergone endovascular treatment of their aneurysm. Larger, prospective studies are needed to determine the effect of VPA on outcome after SAH.