Abstracts

Rationale: Topiramate (TPM) is not widely recognized as an efficacious drug in refractory status epilepticus (RSE). Our experience with use of TPM as an adjunctive antiepileptic drug (AED) in RSE has been positive. We sought to define characteristics and outcome data of our RSE patient population treated with TPM over the past seven years. Methods: Retrospective analysis of patients identified as having RSE between 2003 and 2009 was performed via chart review. After exclusions (use of TPM at the onset of RSE, any AEDs other than continuous IV anesthetics or benzodiazepines used after TPM initiated, incomplete patient data), 23 patients were identified as having been treated with TPM for RSE. Data collected on each patient included age, gender, history of prior seizure disorder, acute medical management, number of days spent in RSE before and after administration of TPM, and final disposition of the patient. Descriptive data were summarized and analyzed using SPSS for patient characteristics and outcome variables. Results: Of the 23 patients in RSE, 9 (39.1%) were male, and 10 (43.5%) had a history of seizures. Roughly one half (52%) had non-structural etiologies vs. 30.4% with structural etiologies; 17.4% were idiopathic. Median time spent in RSE was seven days and 14/23 (60.8%) were in RSE 48 hours or less prior to use of TPM. All had failed a typical initial treatment regimen including a combination of benzodiazepines, propofol, and either phenytoin or loading doses of their home AEDs. In 11 (47.8%) patients, cessation of RSE occurred within three days of initiating TPM. In 20/23 (87%) patients, cessation of RSE was documented within one week. A majority (17/23 or 73.9%) received TPM dosing of 100 mg every four or six hours; four of these patients were given an initial single loading dose prior to the scheduled dosing. Disposition to home was documented in 4/23 (17.4%) patients, to in-patient rehabilitation in 2/23 (8.7%), and to either skilled nursing or long-term acute care facilities in 12/23 (52.2%). Five patients (21.7%) died in our group: in four patients, care was withdrawn because of prolonged medical complications; one patient had respiratory arrest following extubation. Termination of RSE was documented in these five patients prior to their death. Conclusions: To our knowledge, this is the largest reported group of patients who were successfully treated with TPM for RSE. Previous reports have established mortality rates as high as 26% in SE (DeLorenzo, 1996) and >30% in RSE (Towne et al., 2003). Mortality in our group treated with TPM was 21.7%. Of the five patients who expired in our study, the immediate cause of death was not RSE; each of these patients had documented cessation of their seizures prior to death. Few data are available regarding medications that may be efficacious in RSE; our study suggests that TPM has potential efficacy in this patient group, possibly due to its multiple mechanisms of action.