What is Neuromyelitis Optica?
Neuromyelitis optica (NMO) is a disease in which immune system cells and antibodies attack and destroy myelin cells in the optic nerves and spinal cord for unknown reasons. Myelin is the protective coating that surrounds nerve fibers in the central nervous system.
Most people have a relapsing-remitting form of NMO, which is characterized by acute episodes of inflammation followed by months or years of remission. The disease can also occur as a single episode that never recurs again, but this form is less common.
Symptoms of Neuromyelitis Optica
There are two main symptoms of neuromyelitis optica:
- Optic neuritis can cause pain in the eye and vision loss.
- Transverse myelitis can cause weakness, numbness, and sometimes paralysis in the arms and legs, loss of sensation, and loss of bladder and bowel control.
A small number of people may experience vomiting before the onset of eye and spinal cord problems.
Treatments for Neuromyelitis Optica
There is no cure for NMO. Treatment for acute NMO attacks is designed to reduce inflammation in your central nervous system, limiting damage, reducing symptoms, and hastening remission. Treatment may include:
- Intravenous high-dose corticosteroids (steroid treatment)
- Plasma exchange (the removal of antibodies from your blood)
- Immunosuppressive agents (medications that reduce the activity of your immune system)
How common is neuromyelitis optica?
NMO affects approximately 4,000 people in the United States and 500,000 worldwide.
Who gets neuromyelitis optica?
Neuromyelitis optica affects both children and adults, but it appears most often during childhood and between the ages of 40 and 50. The relapsing-remitting form of NMO is much more common in women, but the single-episode form of the disease affects men and women equally.
How is neuromyelitis optica diagnosed?
Early diagnosis is important because episodes of NMO can have devastating, irreversible effects. The process of diagnosing this disease may include the following:
- Medical history
- Neurological exam to test your mobility, muscle strength, coordination, sensation, memory, cognitive ability, speech, and vision
- MRI scan of your brain, optic nerves, and spinal cord
- Lumbar puncture to examine your spinal cord fluid
- Ophthalmology (eye and vision) tests
- Blood tests
- Evoked potentials tests to measure the response of your nerves to stimulation