De novo convulsive status epilepticus in patients with multiple sclerosis treated with dalfampridine.

BACKGROUND: Dalfampridine extended release (DAL) is a broad-spectrum voltage-gated potassium channel blocker that is indicated in multiple sclerosis to improve the nerve conduction of demyelinated axons. Seizures are a known side effect of DAL, which is contraindicated in patients with a history of epilepsy.

OBJECTIVE: Three cases of multiple sclerosis (MS) with de novo convulsive status epilepticus (CSE) probably related to dalfampridine administration are described.

METHODS: No patients had a history of seizures or renal impairment. Biological tests were normal. A brain magnetic resonance imaging (MRI) showed diffuse cortical and subcortical atrophy without active inflammatory lesions.

RESULTS: All three patients presented with CSE that was attributed to DAL and so was discontinued.

CONCLUSION: These case reports illustrate that, aside from seizures, de novo CSE is a potential complication of MS patients treated with DAL.