Anti-leucine-rich Glioma Inactivated-1 Encephalitis Associated with Essential Thrombocythemia

Abstract

Anti-leucine-rich glioma inactivated-1 (anti-LGI1) encephalitis is a subgroup of autoimmune encephalitis. We herein report the case of a 60-year-old man who presented with typical symptoms, including short-term memory loss, mental abnormalities, hyponatremia and seizures characterized by faciobrachial dystonic seizures and who was diagnosed with anti-LGI1 encephalitis. At the same time, he was diagnosed with essential thrombocythemia. A significant improvement was obtained by treatment with corticosteroid, immunoglobulin, mycophenolate mofetil, and hydroxyurea. Autoimmune diseases are associated with a significantly increased risk of developing myeloproliferative neoplasms, which may explain the coexistence of anti-LGI1 encephalitis and essential thrombocythema in this patient; however, but more cases and studies are needed to determine whether there is any correlation between these conditions. A 60-year-old man with an 18-month history of shortterm memory loss, convulsions, mental abnormalities, as well as speech confusion and hallucination, which had persisted for 20 days, was referred to our hospital in November 2016. He had visited two hospitals previously and oxcarbazepine (600 mg/day) and lamotrigine (200 mg/day) had been prescribed to control his seizures. The frequency of the patient's seizures increased, even when he was taking his medications. Twenty days prior to hospitalization, the patient developed agitation, anxiety, speech confusion, irritability, inability to recognize his family members, visuo-spatial disorientation, phonism, and visual hallucination.A physical examination disclosed apathy, short memory