title: Bilateral invasive electroencephalography in patients with tuberous sclerosis complex: a path to surgery?
abstract: OBJECTIVE
  Many children with epilepsy and tuberous sclerosis complex (TSC) have multiple tubers on MR imaging and poorly localized/lateralized video electroencephalography (EEG) findings. Given the long-term risks associated with frequent seizures and multiple antiepileptic drugs, along with improved success in identifying focal epileptogenic zones in patients with multifocal lesions, the authors used bilateral intracranial EEG to lateralize the epileptogenic zone in patients with nonlateralizable noninvasive preoperative evaluations.
  
  
  METHODS
  A retrospective analysis from January 1, 1998, to June 30, 2008, identified 62 children with TSC who were presented at a surgical conference. Of the 52 patients undergoing diagnostic or therapeutic procedures during the study period, 20 underwent bilateral intracranial EEG. The presurgical testing results, intracranial EEG findings, surgical interventions, and outcomes were reviewed.
  
  
  RESULTS
  Fourteen of 20 patients had intracranial EEG findings consistent with a resectable epileptogenic zone. One patient is awaiting further resection. Five patients had findings consistent with a nonresectable epileptogenic zone, and 1 of these patients underwent a callosotomy. Seven patients had Engel Class I outcomes, 1 was Class II, 3 were Class III, and 3 were Class IV (mean follow-up 25 months).
  
  
  CONCLUSIONS
  Bilateral intracranial EEG can identify potential resectable seizure foci in nonlateralizable epilepsy in TSC. Although 6 of 20 patients did not undergo resection (1 patient is pending future resection), significant improvements in seizures (Engel Class I or II) were noted in 8 patients. In the authors' experience, this invasive monitoring provided a safe method for identifying the ictal onset zone.
authors: Department of Neurology, New York University School of Medicine, New York, New York, USA. ccarlso2@gmail.com
authors: Chad
authors: C
authors: Carlson
authors: Federica
authors: F
authors: Teutonico
authors: Robert E
authors: RE
authors: Elliott
authors: Yaron A
authors: YA
authors: Moshel
authors: Josiane
authors: J
authors: LaJoie
authors: Daniel
authors: D
authors: Miles
authors: Orrin
authors: O
authors: Devinsky
authors: Howard L
authors: HL
authors: Weiner
mesh_terms: D000927:Anticonvulsants / Q000627:therapeutic use; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D004351:Drug Resistance; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000009:adverse effects / Q000379:methods*; D004827:Epilepsy / Q000601:surgery; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007223:Infant; D015225:Magnetoencephalography; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods*; D049268:Positron-Emission Tomography; D012640:Seizures / Q000209:etiology / Q000628:therapy; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D014402:Tuberous Sclerosis / Q000175:diagnosis* / Q000601:surgery*
chemical_list: D000927:Anticonvulsants