Clinical and imaging features and treatment response of anti-NMDAR encephalitis combined with MOGAD

Background: To investigate the clinical, imaging features, immunotherapy of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) combined with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Methods: A total of 124 patients with NMDARE and 86 patients with MOGAD were screened from an ongoing prospective cohort study (Clinical and Imaging Patterns of Neuroinflammation Diseases in China, CLUE). Ten NMDARE combined with MOGAD patients, were finally enrolled in this study. Clinical and imaging data and follow-up results characteristics were collected and analyzed. Results: In these 10 patients with NMDARE combined with MOGAD, 7 patients (70 %) showed recurrent courses. In all 26 episodes, 14 episodes (53.8 %) showed encephalitis-related symptoms, 6 episodes (23.1 %) showed demyelination-related symptoms, 6 episodes (23.1 %) showed both. The median CSF leukocytes were 13/mu L (range 1-413) and the median protein was 0.43 g/L (range 0.22-0.70). MRI lesions were found involving the optic nerve (2/10), spinal cord (3/10), deep gray matter (3/10), cortex (6/10), subcortex (7/10), brainstem (5/ 10) and cerebellum (4/10). Leptomeningeal enhancement was found in 3 patients. All patients received high- dose intravenous methylprednisolone and immunoglobulin therapy during attacks. Seven patients received rituximab (RTX). The median annualized recurrence rate (ARR) reduced significantly following RTX treatments (z =-2.201, p = 0.028), and achieved good outcomes at the last follow-up visit (modified Rankin scale score <= 2). Conclusion: NMDARE combined with MOGAD represents a unique characteristic of autoantibody-mediated encephalitis. Coexistence of NMDAR and MOG antibody may indicate high recurrence risk. RTX may be a relatively efficient therapeutic option.