title: Epileptic Zone Resection for Magnetic Resonance Imaging-Negative Refractory Epilepsy Originating from the Primary Motor Cortex.
abstract: OBJECTIVE
  Because of the balance between achieving complete seizure freedom and minimizing the postoperative neurologic deficits, surgery for refractory epilepsy originating from the primary motor cortex is difficult. Here, we report the outcomes of surgery for magnetic resonance imaging-negative refractory epilepsy originating from the primary motor cortex in a case series.
  
  
  METHODS
  Nine patients with refractory epilepsy originating from the primary motor cortex underwent intracranial electrodes implantation after preoperative evaluation. Subdural grid electrodes and depth electrodes were implanted through craniotomy assisted by stereotactic technique. We delineated the epileptic zone and executed tailored resection according to results of intracranial electroencephalography and mapping. The patients were followed up for at least 1 year. Muscle strength was evaluated at different postoperative times (day 1, 2 weeks, and 1 year).
  
  
  RESULTS
  Regarding seizure outcome at the last follow-up, Engel class I outcome was achieved in 5 patients, class II was achieved in 3 patients, and class III was achieved in 1 patient. All cases had postoperative hemiparesis of different degree on the first day after operation. Three patients experienced distal muscle strength of single limb with grade 3 or lower and had obvious dysfunction at 1 year after operation. Six patients experienced distal muscle strength of grade 4 or 5 (Medical Research Council 6-point scale) and had no obvious dysfunction at that time.
  
  
  CONCLUSIONS
  Most patients of refractory epilepsy originating from the primary motor cortex were seizure free and had no obvious neurologic deficits at follow-up. Epileptogenic zone resection may not always be contraindicated for patients with nonlesional refractory epilepsy originating from the primary motor cortex.
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Meng
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: Department of Neurology, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Electrophysiology, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Lanmei
authors.initials: L
authors.lastname: Su
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhaozhao
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Aviational General Hospital of China Medical University, Beijing, China; Beijing Institute of Translational Medicine of Chinese Academy of Sciences, Beijing, China. Electronic address: guoqiangchen08@sina.com.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002648:Child; D000069279:Drug Resistant Epilepsy / Q000000981:diagnostic imaging* / Q000601:surgery*; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000000981:diagnostic imaging*; D019635:Neurosurgical Procedures / Q000379:methods*; D055815:Young Adult
keywords: Muscle strength; Paralysis; Primary motor cortex; Refractory epilepsy; Surgery