Risk factors for epilepsy after cerebral revascularization in patients with moyamoya disease

Objective To investigate the risk factors of epilepsy in moyamoya disease (MMD) patients after cerebral revascularization. Methods We conducted a retrospective study on 213 patients with moyamoya disease admitted to Department of Neurosurgery, Huashan Hospital, Fudan University from January 2014 to December 2015. A total of 240 sides (hemispheres) of cerebral revascularization were performed, including 25 pediatric patients (29 sides) with indirect revascularization surgery (encepho-duro-myo-synangiosis, EDMS). The remaining 188 patients (211 sides) underwent combined revascularization (EDMS + superficial temporal artery-middle cerebral artery anastomosis). All patients underwent clinical follow-up and postoperative outcome was assessed using modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were used to study the clinical risk factors for postoperative seizures in patients with moyamoya disease. Results All 213 patients underwent successful cerebral revascularization in 240 sides. The bridge vessels were confirmed unobstructed via digital subtraction angiography (DSA) post operation. Four patients(1.9%) developed new cerebral infarction, 1(0.5%) had cerebral hemorrhage, 19(8.9%) had hyperperfusion syndrome and 28(13.1%) had seizures. Among 213 patients, 198 were successfully followed up for the duration of 2-24 months, with an average of 12.0±5.4 months. Postoperative mRS were 0-2 points in 184 cases, 3-5 points in 9 and 6 points in 5. Univariate analysis showed that the side of moyamoya disease, Suzuki staging, postoperative new cerebral infarction, cerebral hemorrhage and hyperperfusion syndrome were clinical factors affecting postoperative seizures in patients with moyamoya disease (all P<0.05). Further multivariate analysis showed that the moyamoya disease lesion was located on the left side (OR=2.615, 95% CI: 1.004-6.814, P=0.049) and new cerebral infarction occurred after operation (OR=11.565, 95% CI: 1.458-91.741, P=0.021) and hyperperfusion syndrome (OR=7.747, 95% CI: 2.650-22.649, P<0.001) were independent risk factors for postoperative seizures in patients with moyamoya disease. Conclusion The new cerebral infarction and hyperperfusion syndrome on the left side and postoperative moyamoya disease are important clinical factors affecting postoperative seizures in patients with moyamoya disease. Key words: Moyamoya disease; Cerebral revascularization; Postoperative complications; Epilepsy; Risk factors