title: Epilepsy control following intracranial monitoring without resection in young children.
abstract: OBJECTIVE
  Intracranial monitoring (IM) is a key diagnostic procedure for select patients with treatment-resistant epilepsy (TRE). Seizure focus resection may improve seizure control in both lesional and nonlesional TRE. IM itself is not considered to have therapeutic potential. We describe a cohort of patients with improved seizure control following IM without resective surgery.
  
  
  METHODS
  Over 12.5 years, 161 children underwent 496 surgeries including intracranial monitoring. We retrospectively reviewed the patients' charts, operative reports, and radiologic scans, under an institutional review board-approved protocol.
  
  
  RESULTS
  Seventeen patients underwent only IM, without additional resective surgery, and seven had a dramatic improvement in their epilepsy; six of the seven patients are seizure-free (Engel class I), and one rarely has seizures (Engel class II). All seven patients had frequent seizures that led to IM: either daily (five patients) or 1-2 per week (two patients). The mean age (± standard deviation, SD) at seizure onset was 1.6 ± 1.3 years (range 0.5-4 years). Etiologies were tuberous sclerosis (3 patients), trauma (1 patient), and unknown (3 patients). Mean age at surgery (± SD) was 4.1 ± 2 years (range 1-7 years), and duration of epilepsy 2.5 ± 1.1 years (range 0.5-4 years). Duration of IM was 11.7 ± 5.6 days (5-19 days). Six patients had bilateral and one unilateral invasive electrodes. At last follow-up, four patients required fewer antiepileptic drugs (AEDs), one had the same medication but a higher dose, and two patients were taking additional AEDs. Follow-up was 30.6 ± 9.5 months (range 19-41 months).
  
  
  CONCLUSIONS
  Although uncommon, patients with TRE may improve after IM alone. The explanation for this observation remains unclear; however, perioperative medications including steroids, direct cortical manipulation, or other factors may influence the epileptogenic network.
authors.affiliation: Department of Neurosurgery, Division of Pediatric Neurosurgery, New York University School of Medicine, New York, New York, USA. jonaroth@gmail.com
authors.forename: Jonathan
authors.initials: J
authors.lastname: Roth
authors.forename: Adeolu
authors.initials: A
authors.lastname: Olasunkanmi
authors.forename: Tracy S
authors.initials: TS
authors.lastname: Ma
authors.forename: Chad
authors.initials: C
authors.lastname: Carlson
authors.forename: Orrin
authors.initials: O
authors.lastname: Devinsky
authors.forename: David H
authors.initials: DH
authors.lastname: Harter
authors.forename: Howard L
authors.initials: HL
authors.lastname: Weiner
mesh_terms: D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003399:Craniotomy; D004599:Electric Stimulation Therapy; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D012189:Retrospective Studies