Very late-onset neuromyelitis optica, a report of two cases.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating autoimmune disease that affects the optic nerves, spinal cord and brain stem. It generally affects women between 30 and 40 years of age and has as a marker the anti-aquaporin-4 (AQP4) antibody. We describe two Caucasian patients, a woman and a man aged 72 and 76 years, respectively, who presented with optic neuritis as the initial manifestation of NMOSD, with positive AQP4 antibodies. Very late-onset NMOSD (over 70 years of age) is very rare and, according to small published series, in these patients, generally non-Caucasian, spinal cord involvement predominates and they have a worse prognosis. We consider that our cases illustrate the importance of including this entity in the differential diagnosis of atypical optic neuropathies even in advanced age, given the severity of this disease, which requires early and aggressive treatment.