[Devic's neuromyelitis optica: diagnosis after 10 years of bilateral severe relapsing optic neuritis]

Neuromyelitis optica, also known as Devic's disease, is a severe idiopathic inflammatory demyelinating disease of the central nervous system that preferentially affects the optic nerve and spinal cord. Neuromyelitis optica has long been thought of as a variant of multiple sclerosis; however, clinical, laboratory, immunological, and pathological characteristics that distinguish it from multiple sclerosis have now been recognized.

A young man presented isolated severe bilateral relapsing optic neuritis. After having evolved over 10 years, the appearance of multiple sclerosis-like lesions on the brain led to the diagnosis of multiple sclerosis. Acute myelitis and the presence of NMO-IgG antibodies in the serum finally led to the diagnosis of neuromyelitis optica.

This case is an illustration of the new criteria in the diagnosis of NMO, underscoring the importance of the positive serum NMO-Ig G antibody to distinguish multiple sclerosis from NMO. It also emphasizes that asymptomatic brain lesions are common in NMO on brain MRIs and symptomatic brain lesions do not exclude its diagnosis.