Limbic encephalitis associated with leucine-rich glioma-inactivated 1 antibodies

Abstract

We describe the case of a patient with confirmed limbic encephalitis associated with leucine-rich glioma-inactivated 1 (LGI1) antibodies. A 59-year-old man presented to the Department of Neurology with bizarre behavior, memory loss, cognitive impairment, visual hallucinations, and myoclonus and facio-brachial dystonic seizures. A brain magnetic resonance imaging (MRI) revealed no hippocampal lesions. Blood tests showed hyponatremia. An electroencephalogram showed disorganization and slowing of background activity. Antiepileptic drugs were ineffective. The patient exhibited considerable improvement following immunotherapy. The diagnosis of limbic encephalitis associated with LGI1 antibodies should be considered in patients with clinical manifestations mimicking psychiatric disorders and in cases of refractory epilepsy especially with faciobrachial dystonic seizures. There is frequently hyponatremia, and cerebral MRI may be normal. Full recovery can be expected with early diagnosis and prompt treatment.