Sex Differences in Clinical Presentation and Treatment Outcomes in Moyamoya Disease

BACKGROUND: Moyamoya (MM) disease is an idiopathic steno-occlusive angiopathy occurring more frequently in females. OBJECTIVE: To evaluate sex differences in preoperative symptoms and treatment outcomes after revascularization surgery. METHODS: We analyzed 430 MM disease patients undergoing 717 revascularization procedures spanning 19 years (1991-2010) and compared gender differences in preoperative symptoms and long-term outcomes after surgical revascularization. RESULTS: A total of 307 female and 123 male patients (ratio, 2.5:1) with a mean age of 31.0 ± 16.7 years and adults-to-children ratio of 2.5:1 underwent 717 revascularization procedures. Female patients were more likely to experience preoperative transient ischemic attacks (odds ratio: 2.1, P = .001) and less likely to receive a diagnosis of unilateral MM disease (odds ratio: 0.6, P = .04). No association was observed between sex and risk of preoperative ischemic or hemorrhagic stroke. There was no difference in neurological outcome because both male and female patients experienced significant improvement in the modified Rankin Scale score after surgery (P < .0001). On Kaplan-Meier survival analysis, 5-year cumulative risk of adverse postoperative events despite successful revascularization was 11.4% in female vs 5.3% in male patients (P = .05). In multivariate Cox proportional hazards analysis, female sex trended toward an association with adverse postoperative events (hazard ratio: 1.9, P = .14). CONCLUSION: Female patients are more susceptible to the development of preoperative transient ischemic attack and may be at higher risk of adverse postoperative events despite successful revascularization. There is, however, no sex difference in neurological outcome because patients of both sexes experience significant improvement in neurological status with low risk of the development of future ischemic events after surgical revascularization. ABBREVIATIONS: ΔmRS score, change in modified Rankin Scale score f-mRS score, final modified Rankin Scale score MCA, middle cerebral artery MM, moyamoya mRS, modified Rankin Scale TIA, transient ischemic attack