Abstracts

The recently completed VA Cooperative study, Treatment of Seizures in the Elderly Population, studied 593 older patients with newly diagnosed seizures in a three arm clinical trial comparing carbamazepine, gabapentin and lamotrigine. The primary outcome measure was retention in the trial for 12 months, a measure of efficacy and tolerability. Differences among the groups were significant, with gabapentin and lamotrigine demonstrating better retention than carbamazepine. The principle factor accounting for this result was tolerability. A secondary outcome measure, proportion of patients remaining seizure-free during the trial, showed no significant differences. We sought to determine whether seizure frequency before enrollment was a determinant of the liklihood of seizure freedom. We divided the patient cohort into two groups: those with 0-1 seizure during the 3 months preceding enrollment in the trial, and those with [gt] 1 seizure during the same period. For each of the two groups we determined the percentage of patients in each arm who were seizure free at 3, 6 and 12 months. In the 0-1 seizure group before enrollment, 80.43% were seizure free at 3 months, 80.36% at 6 months, and 73.74% at 12 months. There were no significant differences among the 3 treatment arms. In the [gt] 1 seizure group 54.17% were seizure free at 3 months, 47.51% at 6 months, and 41.81% at 12 months. Again, there were no significant differences among the 3 arms. Seizure frequency when seizures are newly diagnosed in the elderly appears to be a predictor of the probability of becoming and remaining seizure-free after treatment has been started. If a patient with lower seizure frequency is seizure-free at 3 months after being treated, it is likely that he/she will remain so for one year. Those with higher seizure frequencies are less likely to remain seizure-free for one year, and this becomes evident at 3 months. The particular antiepileptic drugs in this trial have little bearing on the liklihood of achieving seizure-freedom. (Supported by Department of Veterans Affairs
Antiepileptic drugs and their placebos were provided by Pfizer and Glaxo)