Anti-leucine-rich Glioma-inactivated 1 Encephalitis Manifesting as Frequent Ictal Pouting and Subtle Memory Disturbance

Intern Med. 2024 Sep 27. doi: 10.2169/internalmedicine.4025-24. Online ahead of print.

Abstract

Anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis is a treatable form of limbic encephalitis, marked by frequent focal seizures and cognitive decline (particularly memory disturbance); however, it can be difficult to diagnose in patients with subtle cognitive decline. Ictal pouting, a rare seizure feature, has not yet been reported in anti-LGI1 encephalitis. A 73-year-old man with anti-LGI1 encephalitis presented with subacute onset of frequent ictal pouting without apparent cognitive decline. Steroid treatment alone resolved seizures and improved subtle visual memory. Middle-aged and older patients experiencing subacute-onset frequent focal seizures should be thoroughly evaluated for memory disturbances to determine the need for anti-LGI1 antibody measurement.

Keywords: Anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis; cognitive decline; ictal pouting; memory disturbance.