Increased adverse events associated with antiepileptic drugs in anti-leucine-rich glioma-inactivated protein 1 encephalitis.

Anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis is a rare autoimmune condition presenting mainly as altered mental state, cognitive dysfunction, and seizure. Antiepileptic drugs (AEDs) are usually initiated to control seizures despite their limited efficacy; however, accumulating clinical experience suggests a high incidence of adverse reactions to AEDs in anti-LGI1 encephalitis. We reviewed the medical records of patients who were diagnosed with anti-LGI1 encephalitis to analyze the adverse effects of AEDs in these patients. Among the 20 patients who were treated with AEDs, 10 (50%) changed their AEDs due to adverse cutaneous drug reaction. Eight of them presented with maculopapular eruption, one with drug rash with eosinophilia and systemic symptoms syndrome, and one with eczema. Causative agents mostly consisted of aromatic AEDs. Oxcarbazepine was discontinued in two additional patients due to hyponatremia. Six patients (30%) discontinued their dose of levetiracetam because of psychiatric manifestations including irritability/aggressive behavior (four patients), insomnia (one patient), and depressive mood (one patient). Clinicians should consider adverse cutaneous drug reaction, psychiatric adverse events, and hyponatremia when selecting AEDs for the treatment of anti-LGI1 encephalitis.