title: Surgical treatment for epilepsy involving language cortices: a combined process of electrical cortical stimulation mapping and intra-operative continuous language assessment.
abstract: OBJECTIVE
  The purpose of this study was to improve the surgical treatment of epilepsy by maximising seizure control while protecting language function.
  
  
  METHODS
  A combined process of extra-operative electrical cortical stimulation (ECS) mapping, direct ECS and intra-operative continuous language assessment was performed during complicated operative cases. Of the 24 epilepsy patients, nine had a complex relationship between the seizure onset zone and the language cortices. The combined process was used in these nine patients. In the other 15 patients, surgical resection was completed based on extra-operative ECS results alone. Evaluations were performed before and after surgery to assess language function and seizure control.
  
  
  RESULTS
  The intra-operative continuous language assessment provided important information at the time of the resection. Seven extra-operative ECS positive language sites were resected without obvious language deficits in two patients. Resection was interrupted by language disturbances in an area where no extra-operative ECS positive site was identified in one patient. In three other patients, functional boundary was undefined in extra-operative ECS result, epileptogenic cortices were maximally resected during the continuous language assessment. In terms of seizure control, 18 of 24 (75%) patients reached Engel's class I, including all nine patients who underwent intra-operative continuous language assessment. One patient had minor surgery-related language deficits three months after resection.
  
  
  CONCLUSIONS
  Intra-operative continuous language assessment proved to be complementary to extra-operative ECS mappings. The combination of ECS mappings and intra-operative continuous language assessment can maximise the resection of epileptogenic cortices and preserve language function in difficult cases involving the language cortex.
authors.affiliation: Beijing Institute of Functional Neurosurgery, Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.forename: Guojun
authors.initials: G
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
authors.forename: Duanyu
authors.initials: D
authors.lastname: Ni
authors.forename: Lixin
authors.initials: L
authors.lastname: Cai
authors.forename: Liang
authors.initials: L
authors.lastname: Qiao
authors.forename: Wei
authors.initials: W
authors.lastname: Du
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology* / Q000601:surgery*; D004558:Electric Stimulation / Q000379:methods*; D004569:Electroencephalography; D004827:Epilepsy / Q000601:surgery*; D005260:Female; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring; D007806:Language Disorders / Q000517:prevention & control*; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D053798:Magnetocardiography; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult
keywords: Electrical cortical stimulation; Epilepsy; Intra-operative assessment; Language mapping; Surgery