title: Intractable occipital lobe epilepsy: clinical characteristics, surgical treatment, and a systematic review of the literature.
abstract: OBJECTIVE
  We reported our experience in the surgical treatment of a relatively large cohort of patients with occipital lobe epilepsy (OLE). We also carried out a systematic review of the literature on OLE.
  
  
  METHODS
  Thirty-five consecutive patients who underwent occipital resection for epilepsy were included. Diagnoses were made following presurgical evaluations, including magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), scalp video-electroencephalogram (EEG) monitoring, and intracranial EEG monitoring. At last follow-up, seizure outcome was classified using the Engel classification scheme.
  
  
  RESULTS
  Twenty-five of 35 patients experienced/had experienced ≥1 type of aura before the seizure. Invasive recordings were used to define the epileptogenic area in 30 of 35 patients (85.7 %). All patients underwent occipital lesionectomies or topectomies. Histopathology revealed: cortical dysplasias, gliosis, dysembryoplastic neuroepithelial tumor, ganglioglioma, and tuberous sclerosis. After a mean follow-up of 44 months, 25 patients (71.4 %) were seizure free (Engel class I), 3 (8.6 %) rarely had seizures (Engel class II), 5 (14.3 %) improved more than 75 % (Engel class III), and 2 (5.7 %) had no significant improvement (Engel class IV). Preoperatively, 12 of 33 patients (36.4 %) had visual field deficits. Postoperatively, 25 patients (75.8 %) had new or aggravated visual field deficits.
  
  
  CONCLUSIONS
  The management of OLE has been aided greatly by the availability of high-resolution diagnosis. Postoperative visual field deficits occur in a significant proportion of patients. Comprehensive intracranial EEG coverage of all occipital surfaces helps to define the epileptogenic area and preserve visual function, especially in cases of focal cortical dysplasia undetectable by MRI.
authors.affiliation: Department of Neurosurgery, Fuzhou General Hospital of Nanjing Command, PLA, North Road 156, West Second Ring, Fuzhou, 350025, China, pengfany@yeah.net.
authors.forename: Peng-Fan
authors.initials: PF
authors.lastname: Yang
authors.forename: Yan-Zeng
authors.initials: YZ
authors.lastname: Jia
authors.forename: Qiao
authors.initials: Q
authors.lastname: Lin
authors.forename: Zhen
authors.initials: Z
authors.lastname: Mei
authors.forename: Zi-Qian
authors.initials: ZQ
authors.lastname: Chen
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Zheng
authors.forename: Hui-Jian
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Jia-Sheng
authors.initials: JS
authors.lastname: Pei
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.forename: Zhong-Hui
authors.initials: ZH
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000150:complications / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D018303:Ganglioglioma / Q000150:complications / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000601:surgery; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011612:Psychosurgery; D016896:Treatment Outcome