Pediatric Relapsing Anti-NMDAR Encephalitis Crossing with Tumefactive Demyelinating Lesion

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalopathy characterized by neuropsychiatric symptoms, autonomic instability, and abnormal movements. Most children who undergo tumor removal and receive appropriate immunosuppressants have substantial neurological improvement. We report a 14-year-old girl with relapsing anti-NMDAR encephalitis who presented with paroxysmal tingling and weakness of the right lower limb. Despite long-term prophylaxis with immunotherapy (azathioprine), tumefactive demyelinating lesion and multifocal subcortical white matter lesions were identified on magnetic resonance imaging, which improved after high doses of steroid therapy. There may be overlap between the clinical manifestations of anti-NMDAR encephalitis and acquired demyelination syndromes in children.