Anti-NMDA receptor encephalitis and MOG-associated demyelination – a case report with long-term follow-up and a systematic review

BACKGROUND: Overlap syndromes of anti-NMDA receptor encephalitis and MOG-mediated demyelination have been reported. In this case we provide a long-term longitudinal follow-up of clinical and imaging characteristics as well as of antibody dynamics. CASE PRESENTATION: We report a 32-year-old male patient who presented with psychosis, decreased consciousness and movement disorders and was tested positive for anti-NMDA receptor antibodies. Forty-four months after symptom onset and diagnosis of autoimmune encephalitis, he suffered from relapse. At this time, the patient developed anti-MOG and anti-Caspr2 antibodies. Treatment with plasmapheresis, steroids and rituximab eventually led to substantial clinical and radiological improvement. Anti-Caspr2 antibodies persisted, anti-NMDA receptor antibodies decreased, while anti-MOG antibodies turned negative again. CONCLUSION: We provide long-term longitudinal follow-up of a patient with anti-NMDA receptor encephalitis who developed triple antibody positivity at the time of relapse. Antibody dynamics were associated with clinical disease course. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-022-02974-x.