Abstracts

In spite of multiple treatment modalities, the outcome has been known as very poor in Lennox-Gastaut syndrome patients. We have tried callosotomy in pediatric Lennox-Gastaut syndrome and Lennox-like syndrome patients and have got successful outcomes. But some patients showed no response. We analyzed the preoperative EEG, pathologic findings and extent of callosotomy in order to identify any relationship with the postoperative outcome of seizure., We retrospectively reviewed 26 patients (19 male patients; mean age at callosotomy, 6.8 years) who were managed as Lennox-Gastaut syndrome (n=22) and Lennox-like syndrome (n=4) at Asan Medical Center from Apr.1993 to Dec, 2005. All the patients had multiple seizure types and mental retardation. The EEG shows generalized spike and slow waves (GSSW) or general paroxysmal fast activities (GPFA) in patients of LGS and intermittent multi-focal spike discharges (IMSD) in patients with Lennox-like syndrome. All of them were refractory to antiepileptic drugs or ketogenic diet. Pre- and post-callosotomy seizure counts were obtained from monthly diary annotation by the family or caregivers at 1, 6 and 12 months., Seizure freedom over 1 year was noted in 6 patients of 26 patients (23.1%). Mean seizure reduction rate at 1, 6 and 12 months were 74.8 %, 62.2%, 58.4% respectively. The existence of family history of epilepsy, abnormal findings on brain MRI, past history of infantile spasms or febrile convulsions had no effect on seizure outcomes after callosotomy. In preoperative EEGs, 19 of 26 patients (73.1%) had generalized slow spike and wave discharges, and others have only GPFA or IMSD. Patients with GSSW discharges achieved significantly better post-operative seizure outcomes at 1 month follow-up (p[lt]0.05). But no outcome difference was observed between these groups at 6 and 12 months[apos] outcomes. The patients with total callosotomy showed better seizure reduction than patients with partial callosotomy, but the difference did not reach statistical significance (P[gt]0.05)., Though we had got relatively successful outcomes after callosotomy in LGS and Lennox-like syndrome patients, we could not find any predictive indicator for better final surgical outcomes. The existence of GSSW in preoperative EEG may predict immediate postoperative outcomes only. Further studies should be required to know the predictive factors for post-callosotomy outcomes in LGS patients.,