[A case of recurrence after more than 20 years from transverse myelitis suspected to be neuromyelitis optica spectrum disorder].

This patient was a 78-year-old woman. In year X-23, she presented with gait disturbance and sensory impairment below the chest level and was diagnosed with and treated for acute transverse myelitis. The neurological symptoms recurred in year X-22, and she was treated under suspicion of opticospinal multiple sclerosis (OSMS). Subsequently, she did not experience a relapse of neurological symptoms; however, she developed left facial paralysis, abnormal sensations in both upper limbs, and muscle weakness in the left lower limb in year X. MRI revealed lesions extending from the medulla oblongata to the C6 level, and serum testing was positive for anti-AQP4 antibodies, leading to a diagnosis of neuromyelitis optica spectrum disorder. This case was considered clinically significant as an example of neuromyelitis optica spectrum disorder recurrence after a long period.