This study focuses on a rare brain disease called anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis. In this condition, the body's immune system mistakenly attacks a protein in the brain, which can cause problems with memory, thinking, behavior, and seizures. While most patients get better with initial treatments, some continue to have long-term symptoms or experience a return of the disease (called a "relapse") months or years later. The goal of this study is to understand how often these relapses and long-term problems happen and to identify which patients are most at risk.

The investigators will look back at the medical records of patients diagnosed with anti-LGI1 encephalitis at five major hospitals in Eastern China. The information about their symptoms, the treatments they received and how they recovered over time are obtained. Then, the investigators will analyze this information to find out what factors are linked to having a relapse or a poor long-term recovery.

By understanding the risks for relapse and poor outcomes, doctors can better identify which patients need closer monitoring and more long-term treatment strategies. The results of this study will help create better guidelines for managing patients with this disease after their initial recovery, aiming to improve their quality of life in the long run.