Clinical characteristics and long-term prognosis of relapsing anti-N-methyl-d-aspartate receptor encephalitis: a retrospective, multicenter, self-controlled study

To analyze the clinical profile and long-term prognosis of relapsing anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis.

This is a retrospective, multicenter, self-controlled study of 10 patients with relapsing anti-NMDAR encephalitis. Relapse was defined as new psychiatric or neurologic syndrome unexplainable by other causes that improved after immunotherapy.

The main symptoms at first onset and relapse included psychiatric symptoms, cognitive impairment, speech dysfunction, seizures, consciousness disturbance, movement disorders, central hypoventilation, and autonomic dysfunction. There were significantly fewer seizures and consciousness disturbances at relapse. At the first onset, the antibody positivity rate was significantly higher in the cerebrospinal fluid (CSF) than in the serum, and abnormal electroencephalograms results were noted in all patients. The relapse rate was 12.2%. After first-onset discharge, the duration of medication intake was 3.10 ± 2.69 months; the relapse time was 18.3 ± 16.5 months. The Modified Rankin Scale (MRS) score at relapse was significantly lower than that at the first onset. The MRS scores at relapse and first onset after immunotherapy were significantly lower than those before immunotherapy. At follow-up, the average duration of antiepileptic drug (AED) intake was < 1 year; the relapse rate was low.

Patients have fewer symptoms and better quality of life at relapse than at the first onset. Active immunotherapy can significantly improve the quality of life during first onset and relapse. Encephalitis antibody testing in the CSF is preferred at first onset and relapse. Increasing antibody titers suggest clinical relapse. Prematurely stopping immunotherapy may lead to relapse, but prolonged AED intake is unnecessary.