Neuromyelitis optica, sometimes called NMO, is a rare yet severe inflammatory process of the central nervous system. The condition mainly affects the spinal cord and the optic nerves, or the nerves that carry signals from the eyes to the brain. As a result, the disease can cause paralysis and blindness.
With neuromyelitis optica, your immune system attacks a substance in your body called myelin—think of it as the insulation around your nerves. Specifically, the myelin cells in the spinal cord and optic nerves are attacked. Usually, people with NMO have flare-ups of the disease that may strike months or years apart. Between these flare-ups, people may have some recovery.
Neuromyelitis optica most often strikes during childhood or when adults are in their 40s. NMO is especially common in young women, but men can develop it, too. Experts used to think that NMO was a type of multiple sclerosis. They now think it may be a different condition. The conditions do have some similar symptoms, but these are usually more severe in neuromyelitis optica. Vision problems with multiple sclerosis usually affect one eye at a time, but NMO may affect both eyes at the same time.
Neuromyelitis optica comes in two forms:
Relapsing form, which has periodic flare-ups, with some recovery in between. This is the more common kind, and women are far more likely to have this form than men.
Monophasic form, which involves a single attack that lasts a month or two. Men and women get this type equally.
These are possible symptoms of NMO:
Pain in the eyes
Loss of vision
Weakness or numbness in the arms and legs
Paralysis of the arms and legs
Difficulty controlling the bladder or bowels
Uncontrollable vomiting and hiccups
Doctors may do a variety of tests if they suspect neuromyelitis optica:
MRI scan of your brain and spinal cord
Samples of your blood and spinal fluid to check for signs of the disease
Tests to check on how well your optic nerves are working
Experts don't consider this condition curable. But doctors can prescribe medicines or other treatments to reduce the effects of the disease and relieve symptoms. These may include:
Corticosteroid drugs to halt the immune system's effect on your nerves
A process called plasmapheresis, which removes proteins from the blood that may be playing a role in the condition
Other treatments to address symptoms such as pain and loss of bowel and bladder control
You may also need help from health care providers to cope with blindness and paralysis.
It's not known whether you can prevent the disease. Certain treatments may help prevent future attacks. You may also need medical care to treat or prevent complications of NMO. These include an inability to breathe, blood clots, and urinary tract infections.
Disability from NMO may become worse over time. Most people with NMO develop weakness in their arms and legs. Others may have more severe symptoms. Many people with NMO need to start using a ventilator, which is a machine that helps them breathe. They may also need to work with an occupational therapist or social worker to address their disabilities.