Acute transverse myelitis is inflammation that affects the spinal cord across its entire width (transversely) and thus blocks transmission of nerve impulses traveling up or down the spinal cord.
In the United States, acute transverse myelitis is estimated to occur in about 1,400 people each year. Also, about 33,000 people are thought to have some type of disability due to the disorder. The entire width of one or more areas of the spinal cord, usually in the chest (thoracic area), becomes inflamed.
What triggers acute transverse myelitis is unknown, but it may result from an autoimmune reaction—when the immune system misinterprets the body's tissues as foreign and produces antibodies that attack and damage tissues. In the case of acute transverse myelitis, the tissues damaged are in the spinal cord. The disorder may develop during the following:
It sometimes develops after mild viral infections or a vaccination.
Usually, symptoms begin suddenly with pain in the back and a bandlike tightness around the affected area of the body (such as the chest or abdomen). Within hours to a few days, tingling, numbness, and muscle weakness develop in the feet and move upward. Urinating becomes difficult, although some people feel an urgent need to urinate (urgency). Symptoms may worsen over several more days and may become severe, resulting in paralysis, loss of sensation, retention of urine, and loss of bladder and bowel control.
The degree of disability depends on the location (level) of the inflammation in the spinal cord and the severity of the inflammation.
Symptoms suggest the diagnosis. But doctors must distinguish acute transverse myelitis from other disorders that cause similar symptoms, such as Guillain-Barré syndrome, spinal cord compression, or blockage of the blood supply to the spinal cord.
Magnetic resonance imaging (MRI) is done first. If MRI does not detect spinal cord compression, a spinal tap (lumbar puncture) is done to obtain a sample of cerebrospinal cord fluid (see How a Spinal Tap Is Done). If acute transverse myelitis is present, the number of certain white blood cells and the protein level in the cerebrospinal fluid is increased. If the disorder is advanced, MRI typically shows swelling of the spinal cord due to inflammation.
Tests, such as a chest x-ray and blood tests, are also done to look for causes. Doctors also ask people about use of drugs.
Occasionally, the disorder recurs in people with multiple sclerosis or lupus. Multiple sclerosis eventually develops in about 10 to 20% of people who have transverse myelitis with no identified cause.
Generally, the more quickly the disorder progresses, the worse the outlook. Severe pain suggests worse inflammation. The outcome is split evenly:
If transverse myelitis is caused by another disorder, that disorder is treated.
If the cause cannot be identified, high doses of corticosteroids such as prednisone are often given to suppress the immune system, which may be involved in acute transverse myelitis.
Plasma exchange—removal of a large amount of plasma (the liquid part of blood—see Sidebar 2: Controlling Diseases by Purifying the Blood) plus plasma transfusions—may also be done. The goal is to remove from the blood any antibodies that are attacking and damaging the spinal cord. However, whether these treatments are useful is unclear.
Symptoms are treated.
Last full review/revision October 2014 by Michael Rubin, MDCM