title: Cerebral hemispherectomy in pediatric patients with epilepsy: comparison of three techniques by pathological substrate in 115 patients.
abstract: OBJECTIVE
  Cerebral hemispherectomy for intractable seizures has evolved over the past 50 years, and current operations focus less on brain resection and more on disconnection. In addition, cases involving cortical dysplasia and Rasmussen encephalitis are being identified and surgically treated in younger individuals. Few studies have been conducted to compare whether there are perioperative differences based on hemispherectomy technique and/or pathological substrate in pediatric patients with epilepsy.
  
  
  METHODS
  In this study the authors compared, stratified by disease, anatomical (37 cases) and Rasmussen functional hemispherectomy (32 cases) with a new modified lateral hemispherotomy (46 cases). Pathological processes included cortical dysplasia (55 cases), Rasmussen encephalitis (21 cases), infarction/ischemia (27 cases), and other/miscellaneous (12 cases). The authors found differences in perioperative clinical factors based on operative technique and/or pathological substrate. In terms of technique, the lateral hemispherotomy was associated with the least intraoperative blood loss, shortest intensive care unit stay, and lowest complication rate. The anatomical hemispherectomy was associated with the longest hospital stay, delayed oral food intake, highest postsurgery fevers, and the highest incidence of shunt requirement. The functional hemispherectomy was associated with the highest reoperation rate for recurrent seizures (25%). In terms of pathology, patients with cortical dysplasia were the youngest at surgery, suffered the greatest amount of blood loss, and required the longest operative/anesthesia times compared with the other pathologically defined groups. Postoperative seizure control (range 0.5-2 years) was not statistically different according to technique or disease process and was similar to that in cases of pediatric temporal lobe epilepsy.
  
  
  CONCLUSIONS
  The authors found differences in perioperative risks and hospital course but not postsurgery seizure control, which vary by hemispherectomy technique and/or disease process. The modified lateral hemispherotomy approach offers various advantages related to operative blood loss and reoperation compared with anatomical and functional hemispherectomies that are especially relevant in younger patients with cortical dysplasia and Rasmussen encephalitis with small and/or malformed ventricles.
authors.affiliation: Division of Neurosurgery, Department of Anesthesiology, The Brain Research Institute, The Mental Retardation Research Center, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors.forename: Shon W
authors.initials: SW
authors.lastname: Cook
authors.forename: Snow T
authors.initials: ST
authors.lastname: Nguyen
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Sue
authors.initials: S
authors.lastname: Yudovin
authors.forename: W Donald
authors.initials: WD
authors.lastname: Shields
authors.forename: Harry V
authors.initials: HV
authors.lastname: Vinters
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Van de Wiele
authors.forename: Rick E
authors.initials: RE
authors.lastname: Harrison
authors.forename: Gary W
authors.initials: GW
authors.lastname: Mathern
mesh_terms: D002540:Cerebral Cortex / Q000002:abnormalities / Q000473:pathology / Q000601:surgery; D002544:Cerebral Infarction / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004660:Encephalitis / Q000473:pathology / Q000601:surgery; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D038421:Hemispherectomy / Q000379:methods*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications / Q000175:diagnosis; D012189:Retrospective Studies; D012307:Risk Factors