Abstracts

Rationale: Levetiracetam (LEV) is one of the most commonly used newer anti-epileptic drugs. Previous studies have shown that LEV suppresses generalized discharges in idiopathic generalized epilepsy, and there has been one published report of the suppression of interictal epileptiform discharges (IEDs) in patients with frequent focal discharges. However, we are not aware of any published studies examining the effect of LEV on IEDs during inpatient video-EEG monitoring. Methods: We reviewed the records of patients with definite epilepsy who underwent video-EEG recording at Columbia Comprehensive Epilepsy Center between January and April 2010. Patients were included if they were: (a) withdrawn from LEV to provoke a seizure; (b) started on LEV; or (c) had a significant change in LEV dosage during monitoring. Clipped samples were made of each patient's daily 24-hour video-EEG files (5 minutes of every hour). These clipped files were reviewed by two blinded readers (CWB, RGE). All IEDs were identified and counted, and mean IED density (IEDs/hour) was calculated for each 24 hour period. IED density while each patient was taking LEV was compared to IED density while each patient was not taking LEV, or taking a reduced dosage. Results: We identified 10 patients with epilepsy who had significant changes in LEV dosage during video-EEG monitoring. Two patients had idiopathic generalized epilepsy, and 8 patients had localization-related epilepsy (five with temporal lobe epilepsy, two with frontal lobe epilepsy, and one with multifocal epilepsy). 4 patients had LEV tapered and then restarted, 2 patients had LEV discontinued, and 2 patients had LEV introduced during recording. The remaining two patients had significant changes in LEV dosage, but never completely stopped the medication. In the 8 patients where spike density off LEV could be compared to spike density on LEV 5/8 had a 16-92% decrease in IED density while taking LEV and in one patient, LEV appeared to completely suppress IEDs. In two patients where LEV was never completely stopped, an increase in LEV dosage resulted in almost complete suppression of IEDs. In one patient (with multifocal epilepsy) the introduction of LEV appeared to increase spike density, and in one patient, LEV did not change spike density. Conclusions: Levetiracetam suppressed interictal epileptiform discharges in the majority of patients during inpatient video-EEG monitoring, including almost complete suppression of discharges in 3/10 patients. Levetiracetam has potential to significantly alter the yield of interictal EEG recordings in patients with epilepsy.