Neuromyelitis optica (Devic's syndrome) is an uncommon, idiopathic, demyelinating syndrome of the central nervous system that preferentially affects the optic nerves and spinal cord. It frequently is misdiagnosed as severe
multiple sclerosis, but usually is readily distinguished from
multiple sclerosis in fully developed cases because of its severity, typical magnetic resonance imaging (MRI) findings (normal brain MRI; longitudinally extensive lesions on spinal cord MRI), and cerebrospinal fluid analysis (polymorphonuclear
pleocytosis and absence of oligoclonal banding). A serum
autoantibody marker, NMO-
IgG, is highly specific for the disorder. Most patients have relapsing disease, and natural history studies confirm early and severe disability. We treat acute
myelitis and
optic neuritis exacerbations with parenteral
corticosteroids and use rescue
plasmapheresis for severe, refractory attacks.
Immunomodulatory drugs used for typical
multiple sclerosis seem ineffective for
relapse prevention. We recommend systemic immunosuppression, usually with
azathioprine and oral
corticosteroids, for most patients. Fulminant disease and breakthrough disease may respond to other forms of humoral
immunotherapy such as
rituximab.