MYTH: Neuromyelitis optica (NMO) and multiple sclerosis (MS) are demyelinating diseases that affect the brain.
FACT: Because both NMO and MS are inflammatory illnesses that affect the myelin sheaths on nerves and the immune system, they're often confused with one another.1 A rare central nervous system disease, NMO differs from MS in that it usually spares the brain and tends to solely strike the optic nerve and spinal cord. NMO causes optic neuritis and transverse myelitis, as well as sensory disturbances and loss of bowel and bladder control. Patients may have a single, severe attack or relapsing attacks followed by months or years of remission. The disease is more common in women and typically affects adults in their 30s and 40s.
MYTH: No definitive blood test can diagnose NMO.
FACT: The antibody NMO-IgG, which isn't found in patients with MS, is found in about 70% of patients with NMO.2 Diagnosis of NMO requires two of the following three supportive criteria: presence of NMO-IgG; a normal brain magnetic resonance imaging (MRI) scan or one showing nonspecific white matter lesions; and a spinal cord MRI showing a lesion extending over three vertebrae.
MYTH: NMO never affects the brain.
FACT: About 10% of patients with NMO have brain lesions, typically an extensive subcortical white matter lesion affecting the hypothalamus, brainstem, or periependymal region.
MYTH: Treatment for NMO is the same as for MS.
FACT: The immunomodulatory drugs used to treat MS, aren't effective for patients with NMO. Instead, corticosteroids and immunosuppressants are given to stop an attack and keep the disease in remission.1,2 Plasmapheresis also may be used to remove circulating antibodies thought to be responsible for the disease.
1. Wingerchuck D, Weinshenker B. Neuro-myelitis optica. Curr Treat Options Neurol. 2008;10(1):55-66. [Context Link]
2. National Institute of Neurological Disorders and Stroke. NINDS neuromyelitis optica information page. http://www.ninds.nih.gov/disorders/neuromyelitis_optica/neuromyelitis_optica.htm. [Context Link]