Effects of eslicarbazepine as add-on therapy on sleep architecture in temporal lobe epilepsy: results from "Esleep" study.

Rationale: Studies looking at the effect of antiseizure medications (ASMs) on the sleep microstructure of subjects with epilepsy are scarce. This study aims to evaluate the impact of eslicarbazepine (ESL) as add-on therapy on the sleep microstructure in temporal lobe epilepsy (TLE).

Methods: Twelve patients affected by TLE were recruited to undergo overnight polysomnography and a subjective evaluation of nocturnal sleep utilizing the Pittsburgh Sleep Quality Index (PSQI) and daytime somnolence through the Epworth Sleepiness Scale (ESS) before and after three months of treatment with ESL as add-on therapy. Ten healthy controls (HC) matched for age, sex and BMI were recruited. Scoring and analysis of sleep macrostructure and cyclic alternating pattern (CAP) parameters were performed.

Results: Ten patients completed the study. The comparison between patients in basal condition (T0) and HC showed a significant lower sleep efficiency (p = 0.049), REM percentage (p = 0.002), higher REM latency (p = 0.02), N2 (p = 0.001) and WASO (p = 0.01). Regarding CAP, patients at T0 showed higher CAP rate in N1 (p = 0.01), lower A1 (%) (p = 0.03), higher A3 (%) (p = 0.01), higher mean duration of A (p = 0.02) and A3 (p = 0.006), A3 index (p = 0.02) than HC. ESL did not induce any significant changes in nocturnal macrostructural polysomnographic variables and PSQI scores. Furthermore, the ESS score showed no modification after treatment. Lower CAP rate in N3 (p = 0.02), phase A2 index (p = 0.02) average number of CAP cycle per sequences and mean duration of CAP sequences (both p = 0.02) was evident after ESL. A trend toward significance was evident for the decrease of CAP rate in N1 (p = 0.09) and N2 (p = 0.09), and for the increase of B phase mean duration (p = 0.07).

Conclusion: We found significant improvement in sleep continuity as measured by CAP after ESL. These findings suggest that ESL may positively modulate sleep fragmentation in patients with TLE, and hence enhance sleep quality. Our results suggest a favourable sleep profile with the use of ESL.