Introduction: Tuberous Sclerosis Complex (TSC) is a major genetic cause of epilepsy. The aim of this work was to characterize epilepsy in a large cohort of TSC patients.

Material and methods: The clinical data of 428 patients with definite TSC were analysed. Eighty patients were followed prospectively from early infancy, before the onset of epilepsy.

Results: Selected results are presented. Epilepsy was present in 366 (85%) patients. Mean follow-up in the prospective group was 4.5 year (range:3 months - 13 years) and in this group 73% of patients had epilepsy. Drug resistant seizures were observed in 61% in the whole cohort of epileptic patients and in 42% of epileptic patients in the prospective group. Infantile spasms were present in 38% of patients in whole cohort and in 17% of patients in the prospective group. In 47 patients, EEG data before the onset of epilepsy were available. In 223 patients mutational analysis was performed and revealed TSC1 mutation 22%, TSC2 mutation in 69%, and no mutation in 8.5% of patients. Epilepsy was more severe and earlier in patients with TSC2 mutation.

Vigabatrin was effective in 53.3% of cases. In 12 patients with drug resistant seizures everolimus treatment for SEGA was introduced and in 6 (50%) resulted in significant improvement of epilepsy control.

Conclusions: Early diagnosis and treatment improves outcome of epilepsy in TSC. Vigabatrin was effective as a first line drug for focal seizures and infantile spasms in TSC. mTOR inhibitor was effective in some patients with drug-resistant epilepsy.