Lamotrigine therapy of epilepsy in tuberous sclerosis

Lamotrigine (LTG), a newer antiepileptic drug (AED), has activity against both partial-onset and generalized seizures. Its reported benefits for behavior, and its effectiveness in Lennox-Gastaut syndrome and other forms of refractory epilepsy, make it a logical choice for treatment of epilepsy in tuberous sclerosis complex (TSC). We present our experience with LTG therapy of epilepsy in 57 patients with TSC.

Patients fulfilled the diagnostic criteria for clinically definite TSC. LTG was initiated and increased until improvement in seizure frequency was noted, intolerable side effects occurred, or maximal doses were reached. Seizure frequency and behavioral changes were recorded during LTG therapy and compared with those prior to the introduction of LTG.

Twenty-four (42%) were seizure free, and 21 (37%) had a >50% reduction in seizure frequency. Eighteen (32%) had subjectively improved behavior and/or alertness with daily activities. Thirty-eight (67%) had no change in this regard, whereas one (2%) became worse. Responders were more likely to not have a history of infantile spasms, and to have experienced only partial seizures (p < 0.05). Otherwise no phenotypic correlations with response were apparent.

Among patients with TSC and epilepsy, LTG was effective and well tolerated, including as initial monotherapy. Improved alertness and behavior were apparent in many patients. The incidence of side effects is similar to that reported for other pediatric populations with symptomatic partial epilepsy. The usefulness of LTG in TSC may relate to an underlying defect of glutamatergic neurotransmission in partial epilepsy.