The effect of lacosamide monotherapy on sleep architecture in patients with epilepsy: a preliminary evidence

Lacosamide (LCM) is a third-generation antiseizure medication (ASM), and its effect on sleep architecture was supported by a few studies in patients with drug-resistant epilepsy in which LCM was used as an add-on treatment. To gather knowledge on ASMs effects on sleep, this study aimed at evaluating the effects of LCM monotherapy on sleep in patients with focal epilepsy. Ten patients diagnosed with epilepsy (mean age 58.00 ± 14.77, 60.0% female, mean monthly seizure frequency 1.20 ± 2.48) starting LCM as monotherapy were included. Sleep architecture was assessed through polysomnography at baseline and at the 6-month follow-up visit. A significant decrease was observed in seizure frequency (p = 0.004), being all patients seizure-free at follow-up. At baseline, eight patients had poor sleep efficiency (< 85%). Sleep efficiency increased at follow-up, with only three patients having an index < 85% (p = 0.022). From baseline to follow-up, a significant decrease was observed in sleep latency (p = 0.022) and wakefulness after sleep onset (p = 0.047). Moreover, a significant decrease was observed in the percentage of stage 1 (Md = 6.70 vs Md = 3.85, p = 0.005) and stage 3 (Md = 27.70 vs Md = 22.35, p = 0.01) of Non-REM sleep. This study suggests that LCM monotherapy may positively impact sleep architecture in patients with epilepsy. The sleep efficiency improvement and the decrease of sleep latency and wakefulness after sleep onset observed at follow-up highlight better sleep stability and continuity in patients treated with LCM. Notably, all patients were seizure-free at follow-up, and seizure freedom may also concur to sleep structure improvement.