Characteristics of clinical relapses and patient-oriented long-term outcomes of patients with anti-N-methyl-D-aspartate receptor encephalitis

Objective: The main syndrome of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is well-characterized, however, the difference in main symptoms between the initial episode and relapses and patient-oriented long-term outcomes has not been previously described.

Methods: To investigate the difference in syndrome symptoms between episodes and patient-oriented outcomes, we administered a structured questionnaire survey for the patients with anti-NMDARE or their family members. From the answers, we analyzed the frequency of main symptoms (e.g., prodromes, abnormal behaviors, memory deficit, speech disorders, involuntary movements, hypo-ventilation) between episodes and patient-oriented outcomes that included the recovery rate for return to previous work or school.

Results: Fifty-six patients were enrolled, and 14 (25%) showed clinical relapse. Details of symptoms at relapse were obtained from 11 patients. Prodrome (27% vs. 96%, p < 0.001), decreased level of consciousness (55% vs. 88%, p = 0.021), seizures (36% vs. 77%, p = 0.012), and involuntary movements (27% vs. 84%, p < 0.001) were significantly less frequent at relapse than initial episode. Although 80% (35/44) of the patients achieved favorable long-term outcomes (modified Rankin Scale score, 0-2), only 61% (27/44) returned to their previous work or school life.

Conclusion: Anti-NMDARE can relapse with milder and more limited symptoms than those of initial episode, and some patients did not return to their previous activities even after achieving a neurologically favorable outcome.