Abstracts

Corpus callosotomy is a treatment option for epilepsy patients who are not resective surgery candidate. EEG as predictor or outcome for corpus callosotomy cases has been studied exclusively among adult population., [italic]Patient selection: [/italic]A retrospective anlysis included all patients under 18 yrs who underwent corpus callosotomy from July 02 to April 06.
[italic]Data collection: [/italic]The demographic data, seizure characteristics and seizure outcome was obtained from the medical records, as well as direct phone interviews at least 6 month following the surgery. The EEG findings were reviewed by two authors (YDP and MM) blinded to the outcome.
[italic]Seizure and EEG patterns classification: [/italic]Seizure type was classified and recorded in to two main categories: Category A for drop attacks and tonic seizures; Category B for GTCS, atypical absence, adverse postures, CPS and myoclonus. Ictal EEG was classified into two different patterns: Type A for generalized desynchronization, spike and wave, and diffuse beta activity; and Type B for focal onset confined to one hemisphere or with secondary generalization.
[italic]Outcome evaluation: [/italic]Two seizure outcomes were defined by the reduction of seizure: Class I [underline][gt][/underline] 90% reduction, and Class II [lt] 90% or less.
[italic]Statistical Methods:[/italic] Chi-Square test run with SPSS 13 package., There were a total of 35 patients followed for 11mo (6-12mo). The average age at surgery and the average age of seizure onset were 7.4 years (range 1 [ndash] 17 yrs) and 2.36 yrs (range 0-10 yrs ) respectively. Sex ratio was 20:15 (M:F). In terms of seizure characteristic, 24 out of 35 (68%) patients belonged to category A while 11/35 (32%) to category B. When correlated with outcome of surgery, patients with Category A seizures showed a tendency to do better than Category B (Category A 85% (12/14) vs. Category B 15% (2/14), p-value 0.077). Ictal EEG pattern did not predict the outcome: Type A 47.6% (10/21) vs Type B 30.8% (4/13), p-value 0.272. Other demographic or pathology characteristics were not different between the two outcome groups., Our data suggest that ictal EEG pattern does not predict outcome following corpus callosotomy among the pediatric population unlike the published data on adult. However, consistent with previous reports, [quot]drop[quot] seizures tended to respond better to this surgical procedure than other seizure types in our population. Careful selection of candidate regarding seizure types, not necessarily ictal EEG patterns, are recommended for corpus callosotomy.,