Abstracts

Tuberous Sclerosis Complex (TSC) is associated with medically refractory epilepsy. Epilepsy surgery, with the goal of resecting epileptogenic brain tissue for seizure relief, has become a viable therapeutic option in TSC. The purpose of the current study is to determine factors associated with seizure relief postoperatively in TSC patients utilizing multicenter data., A retrospective analysis of patients with TSC following surgery for relief of epilepsy was performed from multiple centers. Seventy subjects were analyzed. We studied patient characteristics (presence/absence of mental retardation, age at TSC diagnosis), electrophysiological characteristics (seizure onset age, ictal/interictal focality), seizure type (i.e., presence/absence of infantile spasms), tuber number, electrophysiological/neuroimaging concordance, surgical variables (age at surgery, surgical method, and number of stages), and postoperative residual dominant tuber as determined by neuroimaging. Data were analyzed for all 70 subjects as a whole and for subjects assessed two years or less postoperatively and more than 2 years postoperatively., 27/70 subjects were seizure free (Engel Class I). Subjects with ictal multifocality, mental retardation, and discordant EEG/MRI data were less likely to achieve seizure freedom. However, only associations between seizure freedom and age at seizure onset, history of infantile spasms, and interictal focality were significant at all postoperative durations. The mean age at seizure onset was 2 years in seizure free subjects compared to 7 months in those with persistent seizures. Only 5/32 subjects with a history of infantile spasms were seizure free postoperatively. Focal interictal discharges were seen in 85% of seizure free subjects versus 32% of subjects with persistent seizures. The number of tubers was significantly associated with poor outcome when measured less than 2 years postoperatively., In patients experiencing seizure freedom following surgery for epilepsy in TSC, ictal focality, normal development, and concordant electrophysiological and neuroimaging data are common findings. However, similar features can also be observed in subjects with postoperative seizures. The current study suggests that later age at seizure onset, no history of infantile spasms, interictal focality, and fewer cortical tubers may be determining factors in seizure freedom.,