Very-Late-Onset Neuromyelitis Optica Spectrum Disorder in a Patient with Breast Cancer and Parkinson Disease.

Anti-aquaporin-4 (anti-AQP-4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disorder resulting in severe, recurrent optic neuritis, transverse myelitis, brain stem syndrome, and other types of neurological involvement. Its median age of onset has been reported to be around 40 years. We report herein a case of very-late-onset NMOSD (76 years of age) and try to promote its awareness as a type of neurological deterioration in elder patients. A 76-year-old woman suffering from Parkinson disease was admitted to our hospital because of consciousness disturbance. Cranial magnetic resonance imaging revealed the presence of fluid-attenuated inversion recovery high-signal-intensity lesions in the right peri- and intralateral ventricle. Part of this lesion and the meninges showed gadolinium enhancement. Physical examination revealed the presence of a tumor in the right breast, which was later diagnosed as invasive ductal carcinoma. In addition, laboratory examinations led to the detection of anti-AQP-4 antibodies in her serum; consequently, the patient was diagnosed as having NMOSD. She received initial pulsed steroid therapy, followed by right mastectomy. Although the patient's consciousness improved significantly, she developed abrupt-onset bilateral leg weakness and multiple longitudinal spinal cord lesions. Additional steroid therapy ameliorated the patient's leg weakness and reduced the swelling of the spinal cord.