Transverse myelitis is a rare disease of the central nervous system involving inflammation in the spinal cord. Transverse’ refers to the inflammation being across the width of the spinal cord and ‘myelitis’ refers to the specific part of the spinal cord affected.
What is Spinal Cord? The spinal cord carries messages (nerve impulses) from the brain to the body and from the body to the brain. It is made up of different types of cells. The cells responsible for transmitting messages are called neurons. Neurons have long extensions called axons which carry the messages up and down the spinal cord. Axons are arranged in bundles called tracts. Some of the tracts carry motor function messages which stimulate muscles to produce movement and some of them carry sensory messages which control sensations such as touch, pain and temperature. To increase the speed at which the messages travel, most axons are surrounded by a whitish fatty substance called myelin which forms a protective covering (sheath) around them. Myelin is produced by specialised cells called oligodendrocytes.
Transverse myelitis is a disease causing injury to the spinal cord with varying degrees of weakness, sensory alterations, and autonomic dysfunction (the part of the nervous system that controls involuntary activity, such as the heart, breathing, the digestive system, and reflexes). The inflammation causes swelling which can block messages (nerve impulses) travelling along the spinal cord. The inflammation can also damage or destroy the myelin sheath surrounding the axons in the spinal cord, probably by damaging the specialised cells which produce myelin (the oligodendrocytes). Messages (nerve impulses) cannot be transmitted properly as myelin is stripped off the axons causing scarring.
The inflammation most commonly occurs in the thoracic section of the spinal cord (the middle section below the neck and above the stomach). The damage affects this area but it can also affect the areas of the spinal cord below the thoracic section: the lumbar section (lower back) and the sacrum (between the hips). Most people with transverse myelitis experience weakness and a change in sensation (unusual feelings) in the lower half of the body and have problems with their bowel and bladder.
Transverse myelitis may be caused by viral infections, spinal cord injuries, immune disorders (including systemic lupus erythematosus, Sjogren’s syndrome, sarcoidosis and multiple sclerosis) or insufficient blood flow through the blood vessels in the spinal cord. It may occur as a complication of such disorders as optic neuromyelitis, multiple sclerosis, smallpox, and measles, or as a complication of chickenpox or rabies vaccinations. Transverse myelitis may be caused by viral infections, spinal cord injuries, immune disorders (including systemic lupus erythematosus, Sjogren’s syndrome, sarcoidosis and multiple sclerosis) or insufficient blood flow through the blood vessels in the spinal cord. It may occur as a complication of such disorders as optic neuromyelitis, multiple sclerosis, smallpox, and measles, or as a complication of chickenpox or rabies vaccinations.
Who gets TM?
Transverse myelitis occurs in adults and children, in both genders, and in all races. Females have a higher risk of transverse myelitis than males. No genetic pattern is known. Transverse myelitis is not related to family history. A peak in incidence rates (the number of new cases per year) appears to occur between\ ages 10 and 19 years and 30 and 39 years. Although only a few studies have examined incidence rates, it is estimated that about 1,400 new cases of transverse myelitis are diagnosed each year in the United States, and approximately 33,000 Americans have some type of disability resulting from the disorder.
Causes
Immune System – Although a cause cannot be established in cases of idiopathic transverse myelitis, the inflammation is thought to be the result of the immune system mistakenly attacking the spinal cord. This is called an autoimmune reaction.
Virus and Infection – Transverse myelitis often develops at the same time as, or soon after, a viral or bacterial infection. The cases of transverse myelitis are also believed to be the result of an autoimmune reaction. Rather than the viral or bacterial infection itself directly causing the inflammation, it is thought that the immune system is stimulated to fight the infection and, mistakenly, also attacks the spinal cord. Viruses that can infect the spinal cord directly are herpes viruses, including the one that causes shingles and chickenpox (zoster) and West Nile virus. Other viruses may trigger an autoimmune reaction without directly infecting the spinal cord.
Vaccinations – Transverse myelitis can also develop after vaccinations, although this is very rare. Again, it is thought that the immune system is triggered to respond to the vaccination and mistakenly attacks the spinal cord.
Multiple sclerosis is a disorder in which the immune system destroys myelin surrounding nerves in the spinal cord and brain. Transverse myelitis can be the first sign of multiple sclerosis or represent a relapse. Transverse myelitis as a sign of multiple sclerosis usually manifests on only one side of your body.
Neuromyelitis optica (Devic’s disease) is a condition that causes inflammation and loss of myelin around the spinal cord and the nerve in the eye that transmits information to thebrain. Transverse myelitis associated with neuromyelitis optica usually affects both sides of the body.
Because some affected individuals also have autoimmune diseases such as systemic lupus erythematosus, Sjogren’s syndrome, and sarcoidosis, some scientists suggest that transverse myelitis may also be an autoimmune disorder. In addition, some cancers may trigger an abnormal immune response that may lead to transverse myelitis.
Symptoms
There are four classic symptoms of transverse myelitis (TM). Patients may have only one symptom, or a combination of the following –
- Weakness of the legs and/or arms – Some patients report stumbling, dragging one foot or notice that both legs seem heavier than normal. Depending on the level of involvement within the spinal cord, coordination or strength in the hands and arms may also be affected.
- Sensory alteration – Patients who are experiencing altered sensitivity usually report numbness, tingling, coldness or burning. Up to 80% of patients experience heightened sensitivity to touch. Some even report that wearing clothes or a light touch with a finger causes significant pain.
- Pain – Up to half of those with TM report pain as the first symptom of the disorder. It can be localized to the back, or appear as sharp, shooting pain that radiates down the legs, arms or around the torso. Loss of the ability to experience pain or temperature sensitivity is one of the most common sensory changes.
- Bowel and bladder dysfunction – Some patients report bowel or bladder dysfunction as their first symptom of TM. This may mean an increased frequency or urge to urinate or defecate, incontinence, difficulty voiding, and sensation of incomplete evacuation or constipation.
Treatment
- Intravenous Steroids – Although there are no clinical trials that support a unique approach to treat patients experiencing TM, it is well recognized as a standard of care that patients suspected to have acute myelitis receive high-dose intravenous methyl-prednisolone for 3-5 days, unless there are compelling reasons not to. The decision to offer continued steroids or add a new treatment is often based on the clinical course and MRI appearance at the end of 5 days of steroids.
- Plasma Exchange (PLEX) – This is often used for those patients with moderate to aggressive forms of TM who don’t show much improvement after being treated with intravenous and oral steroids. Again, there has not been a clinical trial that proves PLEX effectiveness in TM but retrospective studies of patients with TM treated with IV steroids followed by PLEX showed a beneficial outcome. PLEX also has been shown to be effective in some patients with other autoimmune or inflammatory central nervous system disorders. Patients particularly benefit from early treatment, and will typically be started on PLEX within days of starting steroids. Particular benefit has been shown if started within the acute or subacute stage of the myelitis or in those patients who exhibit active inflammation on MRI. However, because of the risks implied by this procedure this intervention is determined by the treating physician on a case-by-case basis.
- Antiviral medication – Some people who have a viral infection of the spinal cord may be treated with antiviral medication.
- Pain medication – Chronic pain is a common complication of transverse myelitis. Medications that may lessen muscle pain include common pain relievers, including acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve).
- Cyclophosphamide – It is a chemotherapy drug that is often used to treat lymphomas or leukemia, is sometimes used. Patients receiving this treatment are carefully monitored for potential complications that may arise from immunosuppression.
Alternative Treatment