Abstracts

Seizures may worsen in many patients with primary generalized epilepsies (PGE) when given traditional antiepileptic drugs (AEDs). We report on our experience with oxcarbazepine (OXC), a new AED in patients with PGE We retrospectively reviewed outpatient charts of epilepsy patients from January 2000 to September 2003. Patients with PGE converted to OXC monotherapy or who had OXC added as part of their polytherapy regimen were identified and the data was analyzed. Available data for patient demographics, seizure severity, side effects, dose of AEDs, concomitant medications, failed AEDs, sodium levels, OXC plasma levels and EEG findings recorded at the time of first visit and each subsequent visit was reviewed. Out of 424 charts, 31 patients with PGE were identified, 20 females and 11 males (age range 14 - 71 years). The median age of onset of seizures was 12 years. Eleven patients had a positive family history of seizures, 13 had no family history and no data were available for 7. All patients showed EEG abnormality of generalized bursts of 3 Hz spike and wave which were predominant in the frontal regions.
Sixteen patients had generalized tonic-clonic (GTC) seizures, 7 had absence seizures and GTC seizures, and 8 had absence seizures, myoclonic jerks and GTC seizures. Most patients had failed at least 2 - 5 antiepileptic drugs. Therapeutic OXC doses ranged from 900-3000mg/day.
Of the 16 patients with GTC seizures, 11 (69%) became seizure free, 1 (6%) had a decrease in seizure frequency and 4 (25%) had no change in seizure frequency. Of 7 patients with absence seizures and GTC seizures, 3 (43%) became seizure free, 2 (29%) had persistent absence seizures, 2 (29%) had no change in seizure frequency. Of 8 patients with absence seizures, myoclonic jerks and GTC seizures, 4(50%) became seizure free, 2(25%) had persistence of few absence seizures and 2(25%) had persistence of some myoclonic jerks.
Of the 11 patients converted to OXC monotherapy, 8 (73%) patients became seizure free for [ge]6 months, 2 (18%) experienced a decrease in seizure severity, and 1 (1%) had no change in seizure severity. Twenty patients received OXC as adjunctive therapy, with regimens including valproic acid, lamotrigine, zonisamide, gabapentin, topiramate and carbamazapine. Ten (50%) patients became seizure free after addition of OXC, 6 (30%) had a decrease in the severity of their seizures, and 4 (20%) with no change in seizure severity.
Twelve (39%) patients had no adverse effects and 19 (61%) patients who experienced adverse effects did not discontinue OXC treatment. The most common side effects([gt]15%) were fatigue, sedation and nausea. Oxcarbazepine appears to have a role in patients PGE and should be considered as monotherapy or adjunctive therapy for patients with PGE who have failed to respond to other AEDs. In this small cohort of 31 patients with PGE, there was no precipitation of absence seizures or myoclonic jerks (Supported by Unrestricted grant from Novartis pharmaceutical corporation)