(Kiosk 1) Lacosamide Toxicity Impacting Rehabilitation in Moyamoya Disease: A Case Report

Case Diagnosis: A 50-year-old female with past medical history of Moyamoya disease and recurrent strokes

Case Description or Program Description: Initial hospitalization was provided after elective right encephaloduroarteriomyosynagiosus due to worsening right-sided cerebral vascular stenosis. Her hospitalization was complicated by right temporal subdural hematoma requiring craniotomy and generalized seizures. She was discharged to inpatient rehabilitation on levetiracetam 1500mg twice daily and lacosamide 200mg twice daily. During her rehabilitation program, she began to have episodes of dysphagia with difficulty managing her secretions. During one episode, the patient appeared in acute distress. In addition to dysphagia, the patient was somnolent, hypertensive, tachycardic, diaphoretic, vomiting, and hypotonic. The patient was oriented and conscious but complained of dizziness. There were no new neurological deficits or clinical indicators of seizure activity.

Setting: Inpatient rehabilitation unit

Assessment/Results: Initial CT brain without contrast did not show any new changes. She was transferred back to acute care neurology. Vascular imaging showed stenosis of the right PCA concerning for posterior circulation hypoperfusion however there was no correlation of blood pressure with the patient’s symptoms. The patient underwent multiple EEG studies which showed epileptogenic potential without epileptic discharges. Lacosamide was increased to 300mg twice daily but paradoxically worsened the frequency of episodes, which included a fall with head trauma. Lacosamide levels were obtained 10 days after the initial episode which determined her level 24.7 mcg/mL, with therapeutic range up to 15 mcg/mL. After discontinuation of lacosamide, her symptoms improved and she returned to her baseline mental status.

Discussion (relevance): Lacosamide is a sodium channel blocker metabolized by the liver. It is often used as adjunctive therapy for seizure disorders. The most common adverse effects of lacosamide include headache, nausea, vomiting, diplopia, dizziness, fatigue, and sedation.

Conclusions: Lacosamide is a frequently prescribed medication for patients with epilepsy. It is important to be aware of its side effect profile as this could impact rehabilitation.