What is the definition of Transverse Myelitis?
Transverse myelitis is a neurological disorder caused by inflammation of the spinal cord, which carries nerve signals from the brain to the rest of the body. The segment of the spinal cord that has inflammation or damage determines the symptoms a person has. Generally, inflammation at one segment causes symptoms at that level and below that level. Most commonly, the upper spinal cord is affected, causing impaired leg movement, and problems controlling the bowel and bladder. The onset of symptoms may be acute (sudden, developing over hours or days) or subacute (developing over weeks). The cause of transverse myelitis may be unknown (idiopathic) or it may be associated with a wide variety of underlying health problems, including infections, immune system disorders, and other inflammatory disorders. Tests that may be used to diagnose transverse myelitis include MRI to look for compression or inflammation of the spinal cord, and a lumbar puncture (spinal tap) to look for evidence of inflammation in the fluid surrounding the spinal cord (cerebrospinal fluid). Treatment options may include intravenous steroids, pain medicines, plasmapheresis (also called plasma exchange), intravenous immunoglobulin (IVIG), and cyclophosphamide. Some people have full or partial recovery from symptoms, while others do not recover any lost function in the affected parts of the body. Most people recover at least partially, although recovery can take up to 2 or 3 years. In general however, if there is no improvement within the first 6 months, a significant recovery is not likely.
What are the causes for Transverse Myelitis?
Researchers are uncertain of the exact causes of transverse myelitis. The inflammation that causes such extensive damage to nerve fibers of the spinal cord may occur in isolation or in the setting of another illness. When it occurs without apparent underlying cause, it is referred to as idiopathic. Transverse myelitis is idiopathic in about 60% of cases. Recents studies have discovered circulating antibodies to the proteins aquaporin-4 and anti-myelin oligodendrocyte which may be the definite cause in some individuals with transverse myelitis. Antibodies are proteins produced by cells of the immune system that bind to bacteria, viruses, and foreign chemicals to prevent them from harming the body. In autoimmune disorders, antibodies incorrectly bind to normal body proteins. Aquaporin-4 is a key protein that carries water through the cell membrane of neural cells. The myelin oligodendrocyte glycoprotein sits on the outer layer of myelin.
The following illnesses or agents have been associated with transverse myelitis:
Infectious agents. Transverse myelitis often develops following viral infections. Infectious agents suspected of causing transverse myelitis include varicella zoster (the virus that causes chickenpox and shingles), herpes simplex, cytomegalovirus, Epstein-Barr, influenza, echovirus, human immunodeficiency virus (HIV), hepatitis A, measles, and rubella. Bacterial skin infections, middle-ear infections (otitis media), syphilis, Lyme disease, and Mycoplasma pneumoniae (bacterial pneumonia) have also been associated with the condition. In some cases, the infectious agent may directly invade the spinal cord and produce symptoms of transverse myelitis. In other post-infectious cases of transverse myelitis, immune system mechanisms, rather than active viral or bacterial infections, appear to play an important role in causing damage to spinal nerves. Although researchers have not yet identified the precise mechanisms of spinal cord injury in these cases, stimulation of the immune system in response to infection indicates that an autoimmune reaction may be responsible.
Autoimmune diseases. Transverse myelitis occasionally develops in people who have other autoimmune diseases. These may include systemic lupus erythematosus, Sjogren’s syndrome, and sarcoidosis.In autoimmune diseases, the immune system, which normally protects the body from foreign organisms, mistakenly attacks the body’s own tissue, causing inflammation and, in some cases, damage to myelin within the spinal cord.
Underlying demyelinating disease of the central nervous system. In some people, transverse myelitis represents the first symptom of multiple sclerosis (MS) or neuromyelitis optica (NMO). A form of transverse myelitis called "partial" myelitis (as it affects only a portion of the cross-sectional area of the spinal cord) is more characteristic of MS. This type of transverse myelitis usually affects only one side of the body.
Neuromyelitis optica typically causes both transverse myelitis and optic neuritis (inflammation of the optic nerve that results in vision loss), but not necessarily at the same time. All patients with transverse myelitis should be evaluated for MS or NMO because patients with these diagnoses may require different treatments, especially therapies to prevent future attacks.
Vaccinations. Rarely, transverse myelitis may develop following certain vaccinations (hepatitis B, measles-mumps-rubella, and diptheria-tetanus). Although it's unclear how transverse myelitis and vaccinations are related, an immune response is suggested.
Cancers. Myelitis related to cancer is uncommon. However, some cancers may trigger an abnormal immune response that may lead to transverse myelitis.
What are the symptoms for Transverse Myelitis?
Transverse myelitis may be either acute (developing over hours to several days) or subacute (developing over 1 to 2 weeks). Initial symptoms usually include localized lower back pain, sudden paresthesias (abnormal sensations such as burning, tickling, pricking, or tingling) in the legs, sensory loss, and paraparesis (partial paralysis of the legs). Paraparesis often progresses to paraplegia (paralysis of the legs and lower part of the trunk). Urinary bladder and bowel dysfunction is common. Many patients also report experiencing muscle spasms, a general feeling of discomfort, headache, fever, and loss of appetite. Depending on which segment of the spinal cord is involved, some patients may experience respiratory problems as well.
From this wide array of symptoms, four classic features of transverse myelitis emerge:
Weakness of the legs and arms: Most people with transverse myelitis will experience weakness of varying degrees in their legs; some also experience it in their arms. Initially, people with this condition may notice that they are stumbling, dragging one foot or 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.
Pain: Up to half of those with transverse myelitis report pain as the first symptom of the disorder. The pain can be localized to the back, or appear as sharp, shooting pain that radiates down the legs, arms or around the torso.
Sensory alteration: Loss of the ability to experience pain or temperature sensitivity is one of the most common sensory changes. Patients who are experiencing altered sensitivity usually report numbness, tingling, coldness or burning. Up to 80 percent of people with transverse myelitis experience heightened sensitivity to touch. Some even report that wearing clothes or a light touch with a finger causes significant pain. Many also experience heightened sensitivity to changes in temperature or to extreme heat or cold.
Bowel and bladder dysfunction: Some people with transverse myelitis report bowel or bladder dysfunction as their first symptom. This may mean an increased frequency or urge to urinate or have a bowel movement, incontinence, difficulty voiding, sensation of incomplete evacuation or constipation.
What are the current treatments for Transverse Myelitis?
As with many disorders of the spinal cord, no effective cure currently exists for people with transverse myelitis. Treatments are designed to manage and alleviate symptoms and largely depend upon the severity of neurological involvement. Therapy generally begins when the patient first experiences symptoms. Physicians often prescribe corticosteroid therapy during the first few weeks of illness to decrease inflammation. Although no clinical trials have investigated whether corticosteroids alter the course of transverse myelitis, these drugs often are prescribed to reduce immune system activity because of the suspected autoimmune mechanisms involved in the disorder. Corticosteroid medications that might be prescribed may include methylprednisone or dexamethasone.
Chronic pain is a common complication of transverse myelitis. Nonsteroidal anti-inflammatory drugs — such as aspirin, ibuprofen (Advil, Motrin, others) and naproxen (Aleve, Naprosyn, others) — can help reduce inflammation and relieve pain. Bed rest is often recommended during the initial days and weeks after onset of the disorder.
Based on patient response and test results, additional therapeutic options may be added. Plasma exchange therapy is often used for those with moderate to severe transverse myelitis who don’t show much improvement after being treated with intravenous steroids. This therapy involves removing the straw-colored fluid in which blood cells are suspended (plasma) and replacing the plasma loss with special fluids. It's not certain how this therapy helps people with transverse myelitis, but it may be that plasma exchange removes antibodies that are involved in inflammation.
Some patients respond very well to intravenous cyclophosphamide (a drug often used for lymphomas or leukemia). It is very important that an experienced oncology team be involved in the administration of this drug, and patients should be monitored carefully. Ongoing treatment with chemical agents that modify immune response (such as azathioprine, methotrexate, mycophenolate or oral cyclophosphamide) can be considered for the small subset of patients that experience recurrent transverse myelitis.
Individuals with permanent physical disabilities may benefit from physical therapy, occupational therapy and vocational therapy.
What is the outlook (prognosis) for Transverse Myelitis?
Recovery from the effects of transverse myelitis usually begins within 2 to 12 weeks after symptoms begin and may continue for up to 2 years or more. However, if there is no improvement within the first 3 to 6 months, significant recovery is unlikely. About one-third of people affected with transverse myelitis experience good or near-complete recovery from their symptoms. For example, they regain the ability to walk and experience few or no long-term urinary or bowel problems, and recover from paresthesias. Another one-third have partial recovery and may continue to have a spastic gait, sensory dysfunction, and urinary urgency or incontinence. The remaining one-third continue to have severe mobility problems and require assistance for the functions of daily living. Unfortunately, it often is not possible to make predictions about individual cases. However, research has shown that a rapid onset of symptoms generally results in poorer recovery outcomes.
Most people with transverse myelitis experience only one episode. In rare cases, the episodes happen again (relapses). Some people recover completely or almost completely, then experience a relapse. Others begin to recover, and then their symptoms get worse before recovery continues. In all cases of relapse, physicians will likely investigate possible underlying causes such as multiple sclerosis or systemic lupus erythematosus since most people who experience relapse have an underlying disorder.
How is Transverse Myelitis diagnosed?
Physicians diagnose transverse myelitis by taking a medical history and performing a thorough neurological examination. A test known as magnetic resonance imaging (MRI) may be performed to identify any inflammation around the spinal cord. Physicians also may perform myelography, which involves injecting a dye into the sac that surrounds the spinal cord. The patient is then tilted up and down to let the dye flow around and outline the spinal cord while X-rays are taken.
Blood tests may also be performed to rule out various disorders such as systemic lupus erythematosus, HIV infection, and vitamin B12 deficiency. In some patients with transverse myelitis, the cerebrospinal fluid that bathes the spinal cord and brain contains more protein than usual and an increased number of leukocytes (white blood cells), indicating possible infection. A spinal tap (lumbar puncture) may be performed to obtain fluid to study these factors.