Abstracts

Rationale: Lacosamide is a new anticonvulsant. There have been anecdotal reports and small case series of its use in status epilepticus and in non-convulsive status epilepticus. Here, we report 4 cases of rapid response of non-convulsive status epilepticus (NCSE) refractory to other anticonvulsants to administration of low dose oral or intravenous lacosamide. Methods: 4 patients in non-convulsive status epilepticus refractory to ? 2 other anticonvulsants were treated with lacosamide. 3/4 patients underwent continuous video EEG monitoring before and after lacosamide initiation. The 4th patient had regular EEG prior to treatment initiation; continuous EEG was started 12 hours after lacosamide initiation. Results: Patients: 4 patients were treated, 3 women, one man, aged 40-82. 2 patients had long-standing cryptogenic localization-related epilepsy, without a clear trigger for the NCSE. 2 patients had new onset seizures presenting with NCSE. One had an old CVA, the other had a new hemorrhage from a previously asymptomatic cavernous hemangioma. Presentations included frequent spells of zoning out and paranoid psychosis (n=1); frequent spells of dysphasia and unresponsiveness (n=2); and fluctuating mental status with recurrent transient confusion (n=1). NCSE had been present for ?2 days in all cases. EEG showed frequent (?1/hour) temporal electrographic seizures in all 4 cases, +/- spread to the whole hemisphere, 2 right temporal, 2 left temporal. In the patients with pre-existing seizures, previous AEDs included levetiracetam and topiramate,and levetiracetam and clonazepam; NCSE persisted in spite of increased levetiracetam dose. In the de novo cases, both patients had failed to respond to lorazepam and levetiracetam and one patient failed to responded to a third AED, phenytoin. Response to lacosamide: NCSE stopped rapidly after low doses of oral (n=2) or i.v. (n=2) lacosamide: Case # 1: Lacosamide was administered orally at 12 hourly interval in escalating 50-100-150 mg doses. Seizure frequency declined from 1/hour to 3/12 hours after the second dose and stopped after the third dose. Case # 2: Lacosamide was administered orally at 12 hourly interval in sequential doses of 50-100-150-150-200-200 mg. Seizure frequency declined from 1/hour to 4/24 hours after the 4th dose and stopped after the 6th dose. Patient was drowsy. Lacosamide dose was reduced to 150 mg bid. Seizure recurred. Levetiracetam dose was reduced from 2g to 1.5 g/day and lacosamide dose was increased back to 200 mg q 12 hourly. Patient became seizure free without side effects. Cases # 3 & 4,with new onset seizures/NCSE. Seizures stopped after the first 100 mg i.v. dose in one case and after two doses of 50-100 mg given 12 hours apart in the other case. Mild transient fatigue and somnolence were experienced in 2/4 patients, with no other side effects. Conclusions: Medically refractory non-convulsive status epilepticus in LRE may respond rapidly to low dose of oral or intravenous lacosamide.A larger study is suggested to corroborate these findings.