Abstracts

Refractory status epilepticus (RSE), defined as status failing to respond to standard treatment regimens, may develop in more than 20% of status cases. Treatment of RSE is a major challenge, as standard therapies are ineffective by definition. After observing several instances of successful control of RSE with felbamate (FBM), we retrospectively reviewed our experience with FBM treatment in RSE. We reviewed medical records for demographic data, epilepsy history, etiology of status, type of status, duration of status before starting FBM, treatments tried and failed, concomitant antiepileptic drugs (AEDs) used with FBM, and FBM dose used. We also recorded outpatient follow-up data with respect to seizure control and functional status. The follow-up duration was at least 1 year (mean 4.2 years). There were 5 patients with RSE successfully treated with FBM. Their ages ranged from 24-72 years (mean 36.5). All patients initially had generalized convulsive status epilepticus. The presumed etiologies were probable encephalitis (2 patients), probable mitochondrial disease, frontal lobectomy for chronic epilepsy, and ischemic stroke. Prior to using FBM, patients had failed 4 to 7 AEDs (average 6.2), including general anesthetics (pentobarbital, propofol, or midazolam). FBM was started 7 to 29 days after onset of status, at a dose ranging from 1200-3600 mg per day. The dose was escalated to 4800 mg per day in one patient. It was always used concomitantly with other AEDs, most commonly phenobarbital (4 patients), valproate (2 patients), phenytoin (2 patients). All patients survived with moderate disability in 3 and return to baseline functional status in 2 patients. However, all but one patient continued to have seizures on long-term follow-up. All patients were able to stop FBM after status was controlled. FBM can be an effective treatment for RSE, possibly because it has multiple mechanisms of action. It should be considered early in the management of RSE, particularly with recurrence of status epilepticus following withdrawal of general anesthesia. In this setting FBM use can be short-term, thereby reducing the concern over idiosyncratic toxicity, which is not known to occur before 23 days of treatment.