Late-onset neuromyelitis optica spectrum disorder mimicking stroke in an elderly Chinese man: Case report.

Context: Few cases of neuromyelitis optica spectrum disorder (NMOSD) with an onset older than 75 years old have been reported.Finding: Herein, we report an 81-year-old Chinese male initially suspected of acute stroke but was ultimately diagnosed with NMOSD.Conclusion: Even in the elderly, a diagnosis of NMOSD should be considered for patients with myelitis, especially those with longitudinally extensive spinal cord involvement. Testing for aquaporin 4 antibody in this scenario is recommended for further confirmation. Once diagnosed, careful consideration of treatment options and close monitoring of side effects are important to improve prognosis in elderly patients.