Predictive Factors for Epilepsy in Moyamoya Disease

Background: Epilepsy cannot always be recognized in patients with moyamoya disease. In this report, the clinical features of patients with epilepsy were evaluated for assessing the predictive factors of epilepsy in moyamoya disease. Methods: A total of 64 consecutive patients with moyamoya disease were included in this study. During their follow-up periods, 7 patients were diagnosed with epilepsy. Then, the patients with epilepsy were compared with the patients without epilepsy regarding their clinical features. Results: Analysis of patient background characteristics revealed a significantly higher incidence of epilepsy in patients with high modified Rankin Scale (mRS) scores, high cerebrovascular attack scores, onset age of 3 years or less, early seizures, cortical involvement, stroke subtype, and diffuse brain atrophy. A logistic analysis of epilepsy data revealed significant differences between the 2 groups in mRS score, cerebrovascular attack score, onset age 3 years or less, early seizure, cortical involvement, stroke subtype, and diffuse brain atrophy. Of these, significant differences were noted in 3 items (mRS score, early seizure, and diffuse brain atrophy) on multivariate analysis. These 3 items were selected as the basis of our new moyamoya disease epilepsy risk scale (MDERS), which we then evaluated. The cutoff value estimated by the receiver operating characteristic curve was set at 1 (sensitivity,.857; specificity,.825) or 2 (sensitivity,.571; specificity, 1.000). Conclusions: Epilepsy in moyamoya disease is associated with clinical factors and is not an independent category. For prediction of epilepsy in moyamoya disease, MDERS is a simple and convenient assessment scale.