Abstracts

In a recent evaluation of 246 well-defined refractory adult epilepsy patients identified at the University of Pennsylvania Epilepsy Center, we found an approximately 5% per year six-month terminal remission rate. We wished to determine what treatment changes or additions lead to remission in our patients. From the 3224 charts at the University of Pennsylvania Epilepsy Center, we identified 246 patients followed from 2000 who met the following criteria: 1) were having at least one seizure per month and 2) had failed at least two antiepileptic drugs (AEDs) at the index date. Records were reviewed to identify current and previous drug therapy, and therapeutic interventions that occurred over the 3 yearobservation period. Changes in therapeutic strategy (surgery, drug addition/removal or dose change) and alterations within three-months of onset of seizure freedom were identified. Overall, 38 of the 246 patients (15.5%) attained six-month terminal remission. Of the 21 patients referred for surgery, 11 attained six-month terminal remission, one after subsequent drug addition. None of the 27 patients with Lennox-Gastaut syndrome (LGS) attained terminal remission, despite an average of 9 drug changes/person. Six month terminal remission in the remaining 198 patients occurred in 13.6%. New antiepileptic drugs were added 320 times, and removed 274 times. Forty-four patients had no addition or removal of medication over the period of observation. The following drugs were added most frequently: levetiracetam: 146; zonisamide: 51, lamotrigine: 24, oxcarbazepine: 21, topiramate: 19. Addition of levetiracetam was associated with the attainment of terminal remission in 14 patients, lamotrigine in 4, and zonisamide in 1. In four patients a combination of levetiracetam plus either zonisamide, valproic acid, topiramate, or lamotrigine were added prior to remission. In four patients, there had not been a change in antiepileptic drug at any time in the three years prior to development of seizure freedom although 3 had dosage changes. In the three months prior to remission, a new antiepileptic drug had been initiated in 14 patients, a dose change was made in 7, and no change in regimen or dose was made in 6. Levetiracetam was the most frequently newly prescribed drug over this three-year period, since its launch occurred proximate to the index date. Assessment of the rate of remission related to rate of initiation of specific drugs yielded the following results: levetiracetam: 18/146 (12.3%), lamotrigine 5/24 (20.8%,) topiramate 1/19 (5.3%), valproic acid 1/9 (11.1%), zonisamide 2/51 (3.92%). The small number of cases for some of the drugs precludes definitive interpretation. Further prospective studies are recommended.