Long-term Functional Outcomes and Relapse of Anti-NMDA Receptor Encephalitis: A Cohort Study in Western China

OBJECTIVE: To study the factors associated with relapse and functional outcomes in patients with anti-NMDA receptor encephalitis in Western China. METHODS: The Outcome of the anti-NMDA receptor Encephalitis Study in Western China was initiated in October 2011 to collect prospective observational data from consecutively enrolled patients with anti-NMDA receptor encephalitis. RESULTS: We consecutively enrolled 244 patients (median age: 26 years, range: 9–78 years; females: 128 [52.45%]) between October 2011 and September 2019. Fatality occurred in 17 (6.96%) patients, and tumors were found in 38 (15.57%) patients. The median follow-up duration was 40 (6–96) months. Of these patients, 84.8% showed clinical improvements within 4 weeks after immunotherapy, with a median modified Rankin Scale of 2 (interquartile range [IQR]: 2–3), and 80.7% (median: 1, IQR: 0–2) and 85.7% (median: 0, IQR: 0–1) had substantial recovery (i.e., mild or no residual symptoms) at 12 and 24 months, respectively. The overall prognosis was still improving at 42 months after onset. Disturbance of consciousness during the first month was the only independent predictor (OR: 2.91, 95% CI: 1.27–6.65; p = 0.01) of a poor functional neurologic outcome. Overall, 15.9% of the patients had one or multiple relapses, with 82.0% experiencing the first relapse within 24 months and 76.9% experiencing relapses that were less severe than the initial episodes. Relapse-related risk factors included the female sex and delayed treatment (p < 0.05). CONCLUSIONS: Most patients achieved favorable long-term functional outcomes. Some patients experienced one or multiple relapses, especially female patients. Timely immunotherapy at onset may reduce the risk of relapse.