Abstracts

Rationale: Apart from their anti-seizure effect, AEDs may have an impact on mood and quality of life (QOL). Relatively little is known about the effect of lacosamide (LCM) on mood and QOL. Methods: Prospective, controlled, single-blind study. All patients had localization-related epilepsy. The LCM group included patients initiating adjunctive LCM treatment for clinical indications. Controls were patients on at least two AEDs with anticipated stable dosing. Patients completed assessments at enrollment and 12 - 16 weeks later. Assessments included Profile of Mood States (POMS), QOLIE-89, Montreal Cognitive Assessment (MoCA), and the A-B Neurotoxicity Scale. Seizure frequency was self-reported. Adherence to LCM was electronically monitored with the Medication Event Monitoring System (MEMS). Patients also completed the Morisky 4-item scale of medication adherence, and rated their ability to take AEDs as prescribed. Data analyses included t-tests and Chi-square to examine between group differences, and the Generalized Estimating Equation (GEE) to examine the effects of LCM on mood and QOL. Results: 18 of 23 LCM patients and 31 of 37 control patients completed the study and were included in the final analyses. These patients (n=49; 21 men; mean age 43, range 18-85) were predominantly African-American or Caribbean (98%); 24.5% did not complete high school. Adherence to LCM over the study period, as measured by MEMS, was 73% (SD=23.4). On the Morisky scale, LCM patients reported 80.5% (SD=26.5) adherence, and their self-ratings reflected "good" adherence over the past month. Univariate analyses revealed no significant between group differences in age (p=0.20), AED load (p=0.55), side-effects (A-B Neurotoxicity Scale; p=0.37), MoCA mental status (p=0.44), seizure freedom (p=0.19), or age of seizure onset (p=0.813). The GEE analysis, with seizure freedom as a factor (0 or ≥1 seizure) revealed significant association between seizure freedom and both POMS Total Mood Distress (TMD, p<.01) and QOLIE-89 total score (p<0.01). After controlling for seizure freedom, there was a significant Group x Time interaction for POMS (p=.036). Post hoc analyses revealed a significant drop in TMD in LCM patients (estimated marginal mean at baseline=49.37, at follow-up=29.71; p=0.02). Based on previously reported benchmarks, clinically significant decrease in mood distress on the POMS occurred in 7 (38%) LCM patients. There was no significant Group x Time interaction for QOL (p=0.07), possibly due to small sample size. Finally, correlation between POMS TMD and Emotional-Wellbeing on the QOLIE-89, a known measure of mood, was significant (r=-0.783; p=0.01). Conclusions: These findings suggest a significant decrease in negative mood states in patients who remained on LCM compared to control patients. While the effect of LCM on the overall QOL did not reach significance, this may be due to small sample size. These findings suggest that LCM may have a favorable behavioral profile.