[NMDA receptor encephalitis in the course of recurrent CNS demyelinating disorders: a case report]

We present the case of a 31-year-old woman who developed N-methyl-d-aspartate (NMDA) receptor encephalitis during the course of relapsing and remitting multiple brain lesions. The patient developed a tingling sensation in the left upper and lower extremities, and was first admitted to our hospital at age 27. She was tentatively diagnosed with multiple sclerosis on the basis of multiple lesions with Gd-enhancement in the brainstem, and 2 separate clinical relapses by age 28. At age 31, she developed a headache and pyrexia, followed by confusion and abnormal behavior. Her symptoms acutely progressed to stupor, and subsequently, she developed oral dyskinesia and athetosis-like involuntary movement of the left arm. The stupor state continued over 2 months. However, she had completely recovered by 3 months after the onset of psychiatric symptoms. Her serum and CSF samples tested positive for anti-NMDA receptor antibodies, and she was diagnosed with NMDA receptor encephalitis. Her serum was negative for anti-AQP4 antibody, but showed weak positivity for antinuclear antibody. Between ages 32 and 34, she experienced 2 clinical relapses, including right-hand clumsiness, confusion, aphasia, and dysphagia. FLAIR images showed a high-intensity area in the brain stem, thalamus, and subcortical white matter. No tumors were found throughout the course. A clinical entity of NMDA receptor encephalitis can include various neurologic disorders, such as the development of recurrent demyelinating brain lesions. Further investigation is required to clarify the pathophysiological role of anti-NMDA receptor antibody in our patient.