Formes atypiques de neuro-myélite optique

Neuromyelitis optica (NMO) classically affects the spinal cord and the optic nerves. We describe here two atypical cases of neuromyelitis optica. The first is a 61-year-old woman who presented two episodes of transverse myelitis without visual involvement. The second was a 26-year-old woman who developed a classical form of neuromyelitis optica with extensive myelitis and optic neuritis but brain MRI showed many lesions in the periventricular white matter suggestive of multiple sclerosis. In both cases, NMO-IgG antibodies were positive in the sera. Discovery of anti-AQP4 has enlarged the spectrum of this disorder; nowadays it includes limited variants of neuromyelitis optica (either recurrent myelitis or isolated optic neuritis) and cases of neuromyelitis optica with abnormalities on the brain MRI.