title: Seizure outcomes after corpus callosotomy for drop attacks.
abstract: BACKGROUND
  Medically intractable epilepsy involving drop attacks can be difficult to manage and negatively affect quality of life. Most studies investigating the effect of corpus callosotomy (CC) on seizures have been limited, focusing on the pediatric population or drop seizures alone, with little attention to other factors influencing seizure outcome.
  
  
  OBJECTIVE
  To assess seizure outcomes after CC in adults and children.
  
  
  METHODS
  Retrospective analysis was performed on all patients who underwent CC (anterior two thirds, 1- or 2-stage complete) at our institution between 1990 and 2011. Change in frequency after CC was assessed for drop seizures and other seizure types. Multiple factors were evaluated for impact on seizure outcome.
  
  
  RESULTS
  Fifty patients met inclusion criteria. The median age was 1.5 years at seizure onset and 17 years at time of surgery. Anterior two-thirds CC was performed in 28 patients, 1-stage complete in 17, and 2-stage complete in 5. All 3 groups experienced a significant decrease in drop seizures (P < .001, P < .001, and P = .020, respectively), with 40% experiencing complete resolution, and 64% dropping at least 1 frequency category. Other seizure types significantly decreased in anterior two-thirds CC and 1-stage complete (P = .0035, P = .001, respectively). Younger age at surgery correlated with better seizure outcomes (P = .043).
  
  
  CONCLUSIONS
  CC for medically refractory generalizing epilepsy is effective for both drop seizures and other seizure types. CC should be considered soon after a patient has been deemed medically refractory because earlier age at surgery results in lower risk and better outcome.
authors.affiliation: Departments of *Neurosurgery; and ‡Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Regina S
authors.initials: RS
authors.lastname: Bower
authors.forename: Elaine
authors.initials: E
authors.lastname: Wirrell
authors.forename: Macaulay
authors.initials: M
authors.lastname: Nwojo
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Wetjen
authors.forename: W Richard
authors.initials: WR
authors.lastname: Marsh
authors.forename: Fredric B
authors.initials: FB
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000601:surgery*; D004830:Epilepsy, Tonic-Clonic / Q000150:complications / Q000601:surgery*; D005260:Female; D038421:Hemispherectomy; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology / Q000601:surgery*; D013575:Syncope / Q000209:etiology* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult