Neuromyelitis Optica

What is Neuromyelitis Optica?

Another name for Neuromyelitis Optica is Devic disease (DD).  It is a chronic disorder of the nerve tissue.  There are two types of neuromyelitis optica.

  • One type is the monophasic type where both the spinal cord and the optic nerves (one or both) are attached over a short time (from days to weeks) but once it subsides, they do not reoccur.
  • The other type, which is more common, has repeat attacks and periods of remission in between. The remission periods can last for weeks, months, or even years.

What are the Symptoms of Neuromyelitis Optica?

The most common symptoms of neuromyelitis optic are myelitis or optic neuritis. Optic neuritis is when the optic nerve becomes inflamed and the eye has pain and loses acuity. It can occur in both eyes but it usually only occurs in one.  An upper respiratory infection might come first.

Transverse myelitis or an inflammation of the spinal cord is the other main symptom of neuromyelitis optica.  This affects sensory and autonomic functions and motor functions.  Pain is common and paralysis has been known to occur.  Loss of control of the bowels and bladder are another side effect.  Other signs can include sensory loss, back pain, stiff neck, and headaches.

Neuromyelitis Optica Causes

In many instances, doctors are not sure of the exact cause of neuromyelitis optica. Still, studies of nerves affected by neuromyelitis optica have improved medical understanding of how the disease operates. In neuromyelitis optica, particular immune proteins known as autoantibodies adhere to other specialized proteins called “water channel proteins” within the spinal cord and the optical nerve. At this point, autoantibodies signal the body’s immune cells to attack, damaging myelin and breaking down healthy nerves and tissues.

Researchers have also noted a significant link between neuromyelitis optica and an individual or familial record of autoimmune conditions. According to research, 50% of those with neuromyelitis optica also deal with the effects of other autoimmune conditions along with their family members or aside from their family members. Also, there have been some cases of the occurrence of neuromyelitis optica associated with infections such as varicella, HIV, chlamydia, syphilis, cytomegalovirus, and the Epstein Barr virus. However, the precise nature of this connection is murky and some infections may also trigger neuromyelitis optica in those predisposed to the condition.

How is Neuromyelitis Optica Treated?

Treatment for neuromyelitis optica usually focuses on dealing with the symptoms of the attack.  At the time, there is no specific type of treatment that has been successful in treating it in the long term, although some immunosuppressive drugs have been used to attempt this and some doctors believe they are useful.  Azathioprine, corticosteroids, mofetil, andmycophenolate are the drugs used most often. Some studies have also show rituximab to be helpful.

Intravenous corticosteroids have been helpful in easing the symptoms of acute attacks as has plasma exchange. Plasma exchange involves removing blood from the body, separating the plasma cells from the blood, mixing blood with a replacement solution, and then returning it to the body.

Low doses of carbamazepine have helped to control sudden tonic spasms that are common with those who have permanent motor deficits.

Neuromyelitis Optica Prevention

Technically there is no actual cure for neuromyelitis optica today, but therapies to treat attacks as they happen, to prevent relapses, and to reduce symptoms do exist. Treatment and prevention of NMO and other NMO spectrum disorders can be divided into two discrete objectives: one focused on controlling the inflammatory damage caused by acute attacks, and the other focused on the maintenance treatment in order to avoid relapses. The former is achieved plasmapheresis and using high-dose intravenous corticosteroids, while the latter is focused on using low-dose corticosteroids as well as nonspecific immunosuppressants. These substances can include cyclosporine, azathioprine, mycophenolate mofetil, tacrolimus, and mitoxantrone. Newer therapy strategies have emerged utilizing monoclonal antibodies such as eculizumab (an anti-C5 monoclonal antibody) and rituximab (an anti-CD20 monoclonal antibody), to prevent an NMO relapse.