title: Outcome of no resection after long-term subdural electroencephalography evaluation in children with epilepsy.
abstract: OBJECTIVE
  The aim of this study was to identify the reasons for and predictors of no resection of the epileptogenic zone in children with epilepsy who had undergone long-term invasive subdural grid electroencephalography (SDG-EEG) evaluation.
  
  
  METHODS
  The authors retrospectively reviewed the consecutive medical records of children (< 19 years of age) who had undergone SDG-EEG evaluation over a 7-year period (1997-2004). To determine the predictors of no resection, the authors obtained the clinical characteristics and imaging and EEG findings of children who had no resection after long-term invasive SDG-EEG evaluation and compared these data with those in a group of children who did undergo resection. They describe the indications for SDG-EEG evaluation and the reasons for no resection in these patients.
  
  
  RESULTS
  Of 66 children who underwent SDG-EEG evaluation, 9 (13.6%) did not undergo subsequent resection (no-resection group; 6 males). Of these 9 patients, 6 (66.7%) had normal neurological examinations and 5 (55.6%) had normal findings on brain MR imaging. Scalp video EEG localized epilepsy to the left hemisphere in 6 of the 9 patients and to the right hemisphere in 2; it was nonlocalizable in 1 of the 9 patients. Indications for SDG-EEG in the no-resection group were ictal onset zone (IOZ) localization (9 of 9 patients), motor cortex localization (5 of 9 patients), and language area localization (4 of 9 patients). Reasons for no resection after SDG-EEG evaluation were the lack of a well-defined IOZ in 5 of 9 patients (4 multifocal IOZs and 1 nonlocalizable IOZ) and anticipated new permanent postoperative neurological deficits in 7 of 9 patients (3 motor, 2 language, and 2 motor and language deficits). Comparison with the resection group (57 patients) demonstrated that postictal Todd paralysis in the dominant hand was the only variable seen more commonly (χ(2) = 4.781, p = 0.029) in the no-resection group (2 [22.2%] of 9 vs 2 [3.5%] of 57 patients). The no-resection group had a larger number of SDG electrode contacts (mean 126. 5 ± 26.98) as compared with the resection group (100.56 ± 25.52; p = 0.010). There were no significant differences in the demographic data, seizure characteristics, scalp and invasive EEG findings, and imaging variables between the resection and no-resection groups.
  
  
  CONCLUSIONS
  Children who did not undergo resection of the epileptogenic zone after SDG-EEG evaluation were likely to have normal neurological examinations without preexisting neurological deficits, a high probability of a new unacceptable permanent neurological deficit following resection, or multifocal or nonlocalizable IOZs. In comparison with the group that underwent resection after SDG-EEG, a history of Todd paralysis in the dominant hand and arm was the only predictor of no resection following SDG-EEG evaluation. Data in this study will help to better select pediatric patients for SDG-EEG and to counsel families prior to epilepsy surgery.
authors: Department of Pediatrics, Division of Pediatric Epilepsy, Rainbow Babies and Children's Hospital, Cleveland, Ohio, USA.
authors: Elia M
authors: EM
authors: Pestana Knight
authors: Tobias
authors: T
authors: Loddenkemper
authors: Deepak
authors: D
authors: Lachhwani
authors: Prakash
authors: P
authors: Kotagal
authors: Elaine
authors: E
authors: Wyllie
authors: William
authors: W
authors: Bingaman
authors: Ajay
authors: A
authors: Gupta
mesh_terms: D002648:Child; D002675:Child, Preschool; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation* / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D010243:Paralysis / Q000209:etiology; D018579:Patient Selection; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D013355:Subdural Space; D013995:Time; D016896:Treatment Outcome