We evaluated the efficacy and side effect profile of ESL treatment in epilepsy patients at our center.

In this retrospective observational study, patients with pharmacologically intractable epilepsy treated with ESL at Boston Children’s Hospital between 6/2014 and 6/2018 were included. Variables including demographics, ESL administration information, ESL adverse effects and tolerability, and seizure frequency (SF) were obtained from medical records with a standard data acquisition tool, patients were evaluated at first and last follow-up (f/u). Response to treatment was defined as greater than 50% seizure reduction (SR).

 38 patients receiving ESL treatment were reviewed and 32 were included. 13 patients were females, and median age was 17 (10.8-20.7, range 6.5-36) yrs. Median f/u durations were 2 months (IQR; 2-3.3) and 12 months (IQR: 5.5-28) at first and last f/u, respectively.  At the last f/u, 11 (34%) patients had a SR of >50%, 10 (32 %) patient had < 50% SR, and 11 (34%) patients discontinued ESL due to adverse effects (6, 18.5 %) or lack of efficacy (9, 27.8%). 3 out of 11 responders became seizure free. SF was significantly decreased at the first f/u [median, IQR; 45(3-120) vs. 8(2-86), p=0.03] and last f/u [median, IQR; 45(3-120) vs. 8(2-125), p=0.05] as compared to baseline. Responders of ESL treatment showed significantly greater SR at last f/u (p=0.003) with less adverse effects (p=0.033) as compared to non-responders. 10 patients developed adverse effects, the most common being sleep problems (5;15%), dizziness (3;10%), irritability (2; 6%), nausea (2; 6%), and hyponatremia (2; 6%). 

ESL was overall well tolerated, with a good response rate in patients with pharmacologically intractable epilepsy.