Abstracts

Rationale: Levetiracetam (LEV) is a wide spectrum antiepileptic agent that has been approved as adjunctive treatment of partial and generalized onset seizures, including generalized tonic-clonic and myoclonic seizures. Its availability in intravenous form facilitates initiation of treatment and replacement therapy. We sought to evaluate the effect of intravenous LEV on EEG findings in patients with idiopathic generalized epilepsy (IGE) and correlate the effect with long term LEV therapy. Methods: We reviewed the records of 22 consecutive patients with IGE who were were admitted to the Epilepsy Monitoring Unit for evaluation of refractory epilepsy and who received intravenous LEV either as initiation or replacement therapy. We reviewed patient demographics, seizure history and classification based on ILAE criteria, previous AED usage, EEG findings prior to and following intravenous LEV and long term seizure control in patients discharged on LEV. We evaluated EEG findings in detail: Bursts of generalized spike-wave (SW) activity were described and their frequency measured (usually hourly) prior to and following administration of intravenous LEV. We also evaluated the timing of EEG changes in relation to administration of LEV. Results: There were 15 females and 7 males with a mean age of 21 years. 13 patients had myoclonic seizures, 15 had generalized tonic clonic seizures and 8 had absence seizures. Two patients were exluded from analysis because of focal features in their seizures and ictal EEG findings. Ten patients had ictal recordings (5 myoclonic, 5 generalized tonic clonic and 3 absence seizures). Nineteen patients had bursts of generalized SW discharges. Following administration of intravenous LEV, 14 patients (74%) had no further burst and 5 had greater than 90% reduction in bursts for the remainder of the monitoring period (14-24 hours). The 2 patients excluded due to focal features had very frequent bursts prior to intravenous LEV and none afterwards. Long term follow up (6-12 months) was available on 9 patients. 5 patients have remained seizure free. One patients with both myoclonic and generalized tonic clonic seizures has only occasional myoclonic seizures. Two patients failed monotherapy with LEV but have been seizure free on combination therapy (1 on LEV and lamotrigine, 1 on LEV and phenytoin). Two patients (1 with myoclonic, 1 with myoclonic and absence seizures) failed therapy and were switched to an alternative medication. Conclusions: Intravenous LEV significantly reduced EEG abnormalities in patients with IGE, abolishing bursts of generalized SW within 1 hour of administration in 74% of patients monitored with continuous video-EEG. The effect is often predictive of a favorable long term response to oral LEV.