Neuromyelitis optica is a demyelinating disorder that affects only the eyes and spinal cord.
Neuromyelitis optica causes acute optic neuritis, sometimes bilateral, plus demyelination of the cervical or thoracic spinal cord. It was previously considered to be a variant of multiple sclerosis (MS—see Multiple Sclerosis (MS)) but is now recognized as a different disorder.
Symptoms include visual loss, paraparesis or quadriparesis, and incontinence.
Diagnosis usually includes brain and spinal cord MRI and visual evoked potentials. Neuromyelitis optica is distinguished from MS because it affects several contiguous spinal segments of the spinal cord, whereas MS typically affects a single segment. Also, unlike in MS cerebral white matter lesions are uncommon in neuromyelitis optica. Blood tests to measure an IgG antibody specific for neuromyelitis optica (aquaporin-4 antibody [also known as NMO-IgG]) may be done to differentiate it from MS.
There is no cure. However, treatment can prevent, slow, or decrease the severity of exacerbations. Methylprednisolone and azathioprine are often used together. Plasma exchange may help people who do not respond to corticosteroids. Rituximab, an anti–B-cell antibody, reduces IgG production and appears to stabilize the disease.
Treatment of symptoms is similar to that for MS (see Symptom control). Baclofen or tizanidine may relieve muscle spasms.
Last full review/revision March 2014 by Brian R. Apatoff, MD, PhD
Content last modified March 2014