Delayed Response to Corpus Callosotomy

At present, the patient is free of drop attacks and has a reduced number of absences that interfere with her lifestyle. Since the procedure, she has not had any generalized tonic-clonic seizures at around 30 months post-surgery. [...]a recent meta-analysis suggested that corpus callosotomy may be significantly more effective than vagal nerve stimulation in achieving 50 and 75% reductions in atonic seizures associated with Lennox–Gastaut syndrome.6 There was no statistically significant difference in tonic, generalized tonic-clonic, complex partial and myoclonic seizures.6 Most studies have consistently reported a >75% reduction in drop attacks and a >56% rate of complete freedom from drop attacks.8 In addition, the procedure has shown a >50% reduction in generalized tonic-clonic seizures and complex partial seizures.7,8 In one study,3 corpus callosotomy demonstrated a >80% reduction in seizures when all seizure types were considered. José F. Téllez-Zenteno, Department of Medicine, Division of Neurology, Royal University Hospital, Saskatoon, Saskatchewan, S7N 0W8 Canada.