Abstracts

RATIONALE: The objective of this study was to evaluate any EEG changes that would occur once patients are changed from their baseline antiepileptic medications (AEDs) to Oxcarbazepine (OXC). Specifically, the changes in the number of sharp waves and spike waves as well as clinical seizure episodes were measured.
METHODS: Thirty-one patients ( male=15, female=16, age range 17 to 54 years old) with known partial seizures were admitted to Robert Wood Johnson Hospital to undergo evaluation for either continued breakthrough seizures and/or excessive medication related side effects from May 2000 to April 2002. The patients underwent Video EEG Monitering study for 48-72 hrs while they were taken off their baseline AED or had the dose reduced while OXC was either started or its dose raised. The baseline AEDs included Carbamazepine (CBZ, dose range 400-1800 mg/d), Phenytoin (PHT, 300-600 mg/d)), Phenobarbital (PB, 90-370 mg/d), and Valproic Acid (VPA, 1500-3000 mg/d). The dose range for OXC was 450 to 3000 mg/d. The Video EEG study was evaluated each day to appreciate any changes in the number of focal spikes or sharp waves.
RESULTS: There were twenty patients that had focal sharp waves and nine patients with focal spikes. Two patients had a mixture of sharp and spike waves on the eeg. Of these findings, ninteen eeg studies had sharps or spikes localizing to the left frontal and/or temporal head region. Five of the patterns showed the abnormality in the right frontal and/or temporal head region. There was one patient with slowing in the right frontal area follwed by generalized spikes with subsequent clinical seizure. Four patients had bifrontal and/or bitemporal sharps and spikes. One patient had multifocal spikes localizing to the right hemisphere and one other patient had bitemporal and bicentral abnormality.
Twenty-two (71%) of the patients had an improvement of their focal pathology on the eeg. Of these, 13 patterns (59%) involved improvement in the sharp waves and 9 (41%) improved in their spikes. One patient had the slowing follwed by genelized discharges and a seizure; however, after the switch to OXC, there were no further clinical episodes. A total of seven patients (22%) showed no improvement on the eeg. One patient[ssquote]s eeg worsened in the number of spikes since the total number went from 61 to 77 after the switch. The most dramatic change was seen in a patient who had 1017 spike waves on CBZ and VPA. This patient[ssquote]s CBZ was discontinued on admission and VPA was reduced by 60%. The OXC dose by discharge was 2700 mg/d. By discharge, the number of spikes lessened to 625.
CONCLUSIONS: Although the goal in treating our patients with epilepsy is to have them seizure free with a good quality of life, we believe that the improvement in the eeg pattern is also importat since it can guide treatment. In our retrospective analysis, we found that the eeg does indeed improve when patients change from the most commonly used AEDs to OXC. This is a positive improvement which can actually have a positive impact on their lifestyle and ultimately seizure control.