Ivy Sign Predicts Ischemic Stroke Recurrence in Adult Moyamoya Patients Without Revascularization Surgery

Background: Although there is a standard guideline for performing revascularization surgery in patients with Moyamoya diseases (MMD), more objective and easily obtainable predictors are still needed. Objectives: In this study, we aimed to evaluate the relationship between an ipsilateral ivy sign and ischemic stroke recurrence in adult MMD patients without revascularization surgery. Methods: We included consecutive MMD patients without revascularization surgery between 2006 and 2014. The ivy sign was defined as a linear or focal high-signal intensity on fluid-attenuated inversion recovery images, and the burdens of ivy sign were rated in each hemisphere. The ischemic stroke recurrence was defined as a new clinical event that accompanied a new brain lesion on magnetic resonance imaging. Results: Overall, 84 patients with 154 hemispheres were analyzed. We found recurrent ischemic stroke in 9 (6%) hemispheres within 3 years. In multivariate analysis, an ipsilateral ivy sign remained an independent predictor of 3-year ischemic recurrence (adjusted hazard ratio [aHR] 10.15, 95% CI 2.10–49.14, p = 0.004). An initial presentation as infarction was also significant (aHR 7.15, 95% CI 1.36–36.78, p = 0.019). The burdens of ivy sign showed a dose-response tendency with the 3-year ischemic recurrence rate (p < 0.001). When comparing the ischemic recurrence rate among 4 groups with and without ivy sign and perfusion defect, the “Ivy sign (+) Perfusion defect (+) group” showed a significantly higher risk in both observed (p = 0.005) and estimated (p = 0.003) 3-year ischemic recurrence than did the other group. Additionally, the “Ivy sign (+) Perfusion defect (–) group” showed a higher recurrence rate than did the “Ivy sign (–) Perfusion defect (+) group”. Conclusions: The ivy sign is associated with ischemic recurrence in adult MMD patients in a dose-response manner. It would be helpful for selecting high-risk patients who need revascularization surgery.