Anti-LGI1 Antibody Encephalitis

ABSTRACT

Leucine rich glioma inactivated (LGI1) encephalitis is an uncommon neurological disorder rarely encountered in clinical practice.However, it is a potentially fatal autoimmune syndrome that can decrease the level of consciousness, possibly progressing to coma.Additionally, unless diagnosed and promptly treated, it can cause permanent cognitive impairment. Since LGI1 encephalitis can initially present with psychiatric symptoms, there can be delays in reaching a proper diagnosis. This report describes a case of a 47-yearold woman with LGI1 antibodies-associated limbic encephalitis who initially presented with psychosis. Her blood tests were normal and no MRI and EEG abnormalities were found. Cerebrospinal fluid analysis was negative for other possible infectious causes. Three months after admission, she was found to be LGI1 antibody positive. LGI1 encephalitis should be suspected in patients with symptoms such as memory loss, confusion, seizures, and psychiatric symptoms. Prompt diagnosis and treatment of LGI1 encephalitis are warranted because prognosis becomes worse when such actions are delayed.