An Autopsy Confirmed Neuromyelitis Optica Spectrum Disorder with Extensive Brain White Matter Lesion and Optic Neuritis but Intact Spinal Cord, Clinically Mimicking a Secondary Progressive Multiple Sclerosis-like Course

A 57-year-old woman presented with optic neuritis with repeated clinical symptoms of focal demyelination of the cerebral white matter and brain stem for 14 years. At the end of the patient's course, the clinical signs mimicked secondary progressive multiple sclerosis, but whether it was caused by interferon administration or neuromyelitis optica spectrum disorders (NMOSD) - or a combination of both or others - was unclear. Histopathological findings indicated the etiology to be NMOSD, with no apparent plaque in spinal cord specimens. This case suggests that an accurate clinical diagnosis requires serum anti-aquaporin 4 antibody measurements as well as an autopsy examination.