Abstracts

Rationale: Status epilepticus (SE) and repetitive seizures (RS) are commonly reported sequelae after brain injury occurring in up to 34% of patients depending on cause and comorbidity. Although the treatment of SE and RS has been standardized to include an escalating approach of benzodiazepines, phenytoin and valproic acid, up to 30% of SE/RS patients remain refractory to initial treatment. The purpose of this study was to evaluate the effectiveness of lacosamide (LCM), a recently approved slow sodium channel blocking agent, as de novo therapy in terminating refractory SE/RS, an approach that has only been studied in small case series throughout the literature. Methods: We retrospectively reviewed all pharmacy dispensing records at Weill Cornell Medical College, a tertiary academic referral center, for LCM usage between 2009 and 2011. Only patients with the diagnosis of SE/RS and concurrent video EEG monitoring (n=67) were selected and of those, 41 patients were excluded because of LCM therapy prior to SE/RS occurrence. The remaining 26 patients were analyzed with respect to clinical presentation, EEG findings as well as LCM dosing and effectiveness (i.e., EEG-proven termination of SE/RS). Successful LCM therapy was defined when: 1) LCM was the only anticonvulsant actively titrated immediately prior to seizure resolution; 2) epileptiform activities on vEEG remained suppressed for at least 24 hours in patients without evidence of burst suppression; and 3) lack of seizure recurrence for at least 48 hours after all sedatives were weaned. All diagnostic criteria were applied by 2 independent examiners. Results: Of the 26 patients, 19 (73%) received the diagnosis of nonconvulsive SE (NCSE) and 7 (27%) nonconvulsive RS (NCRS) refractory to standard SE treatment approach. The median age of all patients was 68 (range 6 to 90) years and (15) 58% were female. The most common admission diagnoses leading to the seizures were brain tumor in 11 patients (42%), intracerebral hemorrhage 7 (27%), ischemic stroke 2 (8%), cardiac arrest 2 (8%), toxic metabolic encephalopathy 2 (8%), cortical dysplasia 1 (4%) and static encephalopathy 1 (4%). Median LCM initiation (first) dose was of 200mg while the 24-hour total dose ranged from 70 to 600 mg with a median dose of 300mg. The most commonly employed LCM maintenance dose was 400 mg every 24 hours in 11 (42%) patients. In 11 (42%) patients LCM led to seizure termination; in 3 (12%) seizures were terminated but not within our time interval criteria; in 1 seizure frequency decreased significantly; and 11 patients experienced no observable treatment benefit. Side effects included P-R interval increase in 1and mild increase of liver enzymes in 10 who were also concomitantly on other medications. Conclusions: In this retrospective case series of refractory SE/RS adjuvant LCM led to seizure termination in 42% (11 of 26 patients) within 24 hours and to seizure improvements in an additional 15% (4 patients). These results point to a potential usefulness of LCM in refractory SE/RS; a prospectively study seems warranted.