Abstracts

Rationale: The objective of this study is to evaluate the importance of serial EEG studies in children with epilepsy associated with tuberous sclerosis complex (TSC). Methods: Thirty-eight children (M: 21, F: 17) diagnosed with TSC and have been through three or more EEG recordings between Jan 1991 and March 2009 were included. Among four patients undergone epilepsy surgery, two patients were excluded because the number of serial EEGs was less than three prior to surgery. Clinical data and EEG findings were obtained from medical records retrospectively. We tried to identify the correlation with seizure outcome and serial EEG findings. Results: The mean seizure onset of age was 12.8 months (from 4 days to 72 months) with mean follow up duration of 81.4 months. Initial seizure types were partial seizure in 17 (44.7%), infantile spasm in 16 (42.1%), and generalized seizure in 5 (13.1%). During serial EEG datas, eight patients (21.1%) showed consistent epileptogenic focus throughout more than three EEG recordings. Their seizures were well controlled with antiepileptic drugs. The other 30 patients (78.9%) revealed migrating multifocal foci. Generalized epileptiform discharges were observed more than once in 14 patients during the follow up period. Fourteen of 38 patients revealed epileptogenic foci from unilateral hemisphere and all of them (100 %) maintained seizure freedom with medical treatment. However, only 10 of 24 (41.6%) patients with epileptogenic foci from bilateral hemisphere achieved seizure freedom (p<0.05). The mean number of epileptogenic foci was 2.2 in patients with seizure free, which was 3.3 in patients with uncontrolled seizure. Conclusions: Twenty-one percents (8/38) of patients with TSC showed consistent interictal epileptiform activity during serial EEG recordings, and their seizures were well controlled with medical treatment. Patients with epileptiform foci from unilateral hemisphere during serial EEGs showed good outcomes.