Levetiracetam in children, adolescents and young adults with intractable epilepsy: efficacy, tolerability and effect on electroencephalogram--a pilot study.

Levetiracetam has been authorized for use in Israel as an add-on therapy for intractable epilepsy since May 2006. The aim of the present study was to document its effectiveness for this indication in children, adolescents, and young adults. The medical files of 78 patients aged 0.5-39 years (mean, 14.2 years) treated at our center for intractable epilepsy were reviewed. All received levetiracetam as add-on therapy following a failure to respond to at least 3 anti-epileptic drugs. Fifty-two patients (67%) had partial epilepsy and the remainder had primary generalized epilepsy. The epilepsy was symptomatic in 57%, cryptogenic in 27%, and idiopathic in 15%. Average age at first seizure was 4.1 years. In 45% of patients, the number of seizures was reduced by half with levetiracetam treatment; 11.5% of the cohort achieved complete remission. There was a statistically significant correlation between clinical seizure control and improvement in the electroencephalography findings (p = 0.0012). The drug was well tolerated, with a retention rate of 69% after one year. The most common adverse effects were irritability and impulsiveness, in 26.9% of patients. Severe behavioral side effects (psychosis, confusion) were experienced by 6.4%. In conclusion, levetiracetam is an effective and tolerable add-on agent for use in most epileptic children, adolescents, and young adults who fail to respond to at least 3 antiepileptic drugs and should be the treatment of choice in this setting. Despite the relatively high rate of behavioral side effects in this study, the retention rate at one year was high.