Abstracts

Rationale: To assess the efficacy and tolerability of adjunctive lacosamide as add-on therapy in a sample of patients with refractory partial-onset seizures predominantly accompanied by intellectual disability. Methods: Fifty-five consecutive patients (23 women, 32 men, aged 8-59 years) with uncontrolled partial-onset seizures received lacosamide (50-500mg/day, mean: 363mg/day) for at least 6 months in addition to 1-2 antiepileptic drugs. More than two thirds of the patients had at least mental retardation. Analysis of efficacy was based on reduction in seizure frequency (>/=50% and 100% responder rates) and percentage of patients using lacosamide at the end of the study. Analysis of safety was based on occurrence of adverse events. Results: Responder rate (>/=50%) was 44% for lacosamide. Seizure freedom during treatment period was achieved in no patient. Retention rate was 80 % for 3 months and 71 % for 6 months. Adverse CNS events (particularly dizziness, ataxia, nausea) were reported by 21 patients, most were of mild to moderate intensity. All adverse events occurred under moderate to high dose co-medication (OXC >/= 1800mg/d, CBZ > 1500mg, LTG SK > 12µg/ml). Adverse cardiac events occurred in two patients (1 st degree av-block / bradycardia with 1st degree av-block respectively) without any clinical signs. Conclusions: Adjunctive lacosamide was well tolerated and provided effective seizure control over 12 weeks in a special sample of patients with difficult-to-control epilepsy predominantly accompanied by intellectual disability. Cardiac monitoring should be considered only in patients at risk (older patients, co-medication with CBZ). Further controlled studies are needed to prove effectiveness of lacosamide in difficult-to-treat patients with chronic epilepsy and intellectual ability.