Long-term Outcomes of Patients with Anti–Leucine-Rich Glioma-Inactivated 1 Encephalitis

Abstract Background: This report aims to provide a detailed description of the clinical manifestation, immunotherapy, and long-term outcomes of 117 Chinese patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis. Methods: We retrospectively selected 117 patients diagnosed with anti-LGI1 encephalitis from the databases of multiple clinical centers from September 2014 to December 2019. The clinical features, ancillary test results, and details of long-term outcomes were analyzed.Results: Among the 117 anti-LGI1 encephalitis patients, 81 (69%) were male and 36 (31%) were female; the median onset age was 51 years (range: 30-77 years). The median time from symptom onset until diagnosis was 8.7 weeks (range: 2-49 weeks). The main features evaluated in our cohort were seizures, cognitive impairment, and mental and behavioral abnormalities. One hundred and nine patients were treated with immunotherapy, After 3-5 days of treatment, the clinical symptoms were somewhat alleviated in all the patients, and their memory, mental ability, and behavior improved. The median follow-up time was 33 months (range: 6-59 months). A total of 19 (16%) patients experienced a relapse; the median duration from onset to the first relapse was 5 (0.3-27) months. There were no mortalities during the follow-up period.Conclusions: The outcome of patients with anti-LGI1 encephalitis is mostly favorable, although some patients continue to suffer from cognitive dysfunction. Early recognition is of great significance for the treatment of anti-LGI1 encephalitis. Prompt adequate immunotherapy has positive implications for the improvement of clinical symptoms of anti-LGI1 encephalitis. Long-term follow-up is important for the assessment of LGI1 antibody-mediated encephalitis.