Transverse myelitis

Definition

Transverse myelitis is an inflammation of the full width of the spinal cord that disrupts communication to the muscles, resulting in pain , weakness, and muscle paralysis.

Description

The symptoms of transverse myelitis are due to damage and/or destruction of the myelin sheath, the fatty white covering of nerve fibers that serves both to insulate the nerve fibers and to speed nervous conduction along them. Areas of missing myelin and areas of scarring along the affected nerves result in slowed or disrupted nervous conduction and muscle dysfunction.

Transverse myelitis may have a gradual onset or a remarkably quick onset. Symptoms of transverse myelitis may reach their peak within 24 hours of onset for some patients (considered the hyperacute form of the condition). Other patients experience a more gradual increase in symptom severity, with peak deficits occurring days (acute form of transverse myelitis) to weeks (subacute form of transverse myelitis) after the initial symptoms first presented. Patients with the quicker onset form and who experience more severe initial symptoms tend to have more complications and a greater likelihood of permanent disability.

Transverse myelitis often occurs in people who are recovering from a recent viral illness, including chickenpox, herpes simplex, cytomegalovirus, Epstein-Barr, influenza, and measles. When this association is present, the condition often follows the more sudden hyperacute course.

Demographics

In the United States, there are only about 4.6 cases of transverse myelitis per million people per year. In the Unites States, about 1,400 people a year develop transverse myelitis; about 33,000 people in the United States have disabilities due to transverse myelitis. Individuals of all ages can be affected; reports have been made of patients ranging from the age of six months to 88 years. The peak ages appear to be 10-19 years and 30-39 years.

About 30-60% of all cases of transverse myelitis occur in individuals who have just recovered (within the previous 8 weeks) from a relatively minor viral infection. Recent vaccination is another risk factor for transverse myelitis. Other individuals at higher risk for transverse myelitis include patients with preexisting autoimmune diseases (such as multiple sclerosis , systemic lupus erythematosus, or Devic's disease); patients with recent histories of infections such as Lyme disease , tuberculosis, or syphilis; and intravenous drug abusers who inject heroine and/or amphetamines.

Causes and symptoms

Although the specific mechanism of transverse myelitis has not been delineated, the basic cause is thought to be an autoimmune response. Under normal conditions, the immune system reacts to the presence of a viral or bacterial illness by producing a variety of immune cells designed to attack the invading viruses or bacteria. Unfortunately, in the case of transverse myelitis, the immune cells mistake the body's own tissues as foreign, and attack those tissues as well. These errant immune cells are called autoantibodies; that is, antibodies that actually attack the body's own tissues.

Symptoms of transverse myelitis can develop over several hours, days, or weeks. The types of symptoms and their severity are dependent on the area of the spinal cord affected. When the transverse myelitis occurs in the neck, the arms and legs will be affected; when the transverse myelitis occurs lower in the back, only the legs will be affected.

Symptoms of transverse myelitis often begin with back pain , headache , achy muscles, flu-like symptoms, and stiff neck. Over hours or days, symptoms expand to include loss of sensation, numbness, dysesthesia (sensations of burning, lightning flashes of pain, prickly pinpoints), muscle weakness, partial or complete paralysis, and impaired bladder and bowel function. Symptoms of weakness and then paralysis usually begin in the feet, ascending over time to the legs, and then to the trunk and arms when the lesion is in the neck. Symptoms are bilateral, meaning that they affect both sides of the body simultaneously. Over time, muscles become increasingly tight and spastic, further limiting mobility. When the muscles of respiration are affected, breathing can be compromised.

Diagnosis

Diagnosis involves meeting specific symptom criteria, as well as demonstrating spinal cord involvement with MRI scanning and examination of cerebrospinal fluid. Symptom criteria include the evolution of symptoms peaking over four hours to 21 days, with symptoms clearly traceable to spinal cord dysfunction, and including muscle weakness or paralysis and sensory defects such as numbness occurring on both sides of the body. The presence of a spinal cord tumor or another condition that is exerting pressure on the spinal cord, vitamin B12 deficiency, or a history of radiation therapy to or cyclophosphamide injection into the spinal cord excludes the possibility of a diagnosis of transverse myelitis.

Treatment team

The mainstay of the treatment team for patients with transverse myelitis will be a neurologist . A rheumatologist, specializing in autoimmune illness, may also be consulted. In order to regain maximum function, a physiatrist (a physician specializing in rehabilitation medicine) may be required, as well as the services of both physical and occupational therapists.

Treatment

Treatment is aimed at calming the immune response that caused the spinal cord injury in the first place. To this end, high doses of intravenous and then oral steroids are the first-line treatments for transverse myelitis. In severe cases of transverse myelitis, the very potent immunosupressant cyclophosphamide may be administered. In patients with moderately severe transverse myelitis unimproved by five to seven days of steroid treatment, a procedure called plasma exchange may be utilized. This procedure involves removing blood from the patient, and separating it into the blood cells and the plasma (fluid). The blood cells are then mixed into a synthetic plasma replacement solution and returned to the patient. Because the immune cells are in the plasma, this effectively removes the damaging immune cells from the body, hopefully quelling the myelin destruction.

Treatments to reverse the process involved in transverse myelitis should be attempted for about six months from the onset of the condition. After that point, treatment efforts should be shifted to effective rehabilitation.

Pain and other dysesthesias (uncomfortable sensations, such as burning, pins-and-needles, or electric shock sensations) are treated with a variety of medications, such as gabapentin , carbamazepine , nortriptyline, or tramadol. Another treatment for pain and dysesthesias is transcutaneous electrical nerve stimulation, called TENS therapy. This involves the use of a device that stimulates the painful area with a small electrical pulse, which seems to disrupt the painful sensation.

Because constipation and urinary retention are frequent problems in the patient with transverse myelitis, medications may be necessary to treat these problems. Oxybutinin, hyoscyamine, tolterodine, and propantheline can treat some of the bladder problems common to transverse myelitis patients. When urinary retention is an issue, sacral nerve stimulation may help the patient avoid repeated bladder catheterizations. Dulcolax, senekot, and bisacodyl can help improve constipation.

Tight, spastic muscles may improve with baclofen, tizanidine, or diazepam . When these medications are given orally, they sometimes result in untenable side effects.

Recovery and rehabilitation

Rehabilitation has both short-and long-term components. Even in the earliest stages of the condition, passive exercises should be performed. Passive exercises involve a physical therapist putting a particular muscle group or joint through range of motion and strengthening exercise , even when the patient cannot assist in its movement. During the recovery phase, the patient should be given progressive exercises to improve strength and range of motion, and to attempt to regain mobility. Physical therapists can also be helpful with pain management, using such techniques as heat and/or cold application, nerve stimulation, ultrasound, and massage. Physical therapy may also be helpful to retrain muscles necessary for improved bladder and bowel control and relief of constipation and urinary retention. Occupational therapists can help the patient relearn old skills for accomplishing the activities of daily living, or strategize new techniques that take into account the patient's disabilities.

Braces or assistive devices such as walkers, wheelchairs, crutches, or canes may be necessary during rehabilitation or permanently.

Prognosis

The area on the spinal cord affected by transverse myelitis will determine the individual's level of functioning. The higher-up the lesion, the greater the disability. High cervical lesions will require complete care; as lesions drop lower and lower in the cervical, thoracic, or lumbar region, the chance to participate in self-care or even to ambulate increases.

Recovery from transverse myelitis seems to follow the law of thirds: about a third of all patients make a full recovery from their level of functioning at the condition's peak, a third make a partial recovery, and a third make no recovery at all. Most patients make a good or even a complete recovery within one to three months of the onset of their symptoms. Patients who have not begun to improve by month three after symptom onset usually will not accomplish a complete recovery from their disability. Factors that do not bode well include abrupt onset of symptoms, prominent pain upon onset, and severe disability and deficit at the peak of the condition.

Resources

BOOKS

Aminoff, Michael J. "Inflammatory disorders affecting the spinal cord." In Cecil Textbook of Internal Medicine, edited by Lee Goldman, et al. Philadelphia: W. B. Saunders Company, 2000.

Schneider, Deborah Ross. "Transverse Myelitis." In Essentials of Physical Medicine and Rehabilitation, 1st ed., edited by Walter R. Frontera. Philadelphia: Hanley and Belfus, 2002.

PERIODICALS

Transverse Myelitis Consortium Working Group. "Proposed diagnostic criteria and nosology of acute transverse myelitis." In Neurology 59, no. 4 (27 August 2002): 499–505

WEBSITES

National Institute of Neurological Disorders and Stroke (NINDS). NINDS Transverse Myelitis Information Page. July 1, 2001 (June 10, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/transversemyelitis_doc.htm>.

ORGANIZATIONS

Transverse Myelitis Association. 1787 Sutter Parkway, Powell, OH 43065. (614) 766-1806. [email protected]. <http://www.myelitis.org/index.html>.

The Johns Hopkins Transverse Myelitis Center. 600 N. Wolfe Street, Baltimore, MD 21287. (410) 502-7099; Fax: (410) 502-6736. [email protected]. <http://www.hopkinsmedicine.org/jhtmc/>.

Rosalyn Carson-DeWitt, MD

Transverse myelitis

Description

Transverse myelitis (TM) is an inflammation or infection of the spinal cord in which the effect of the lesion spans the width of the entire spinal cord at a given level. The spinal cord consists of four regions: the cervical (neck), followed by the thoracic (chest), the lumbar (lower back) and the sacral (lowest back). TM can occur in any of these regions. The disease is uncommon, but not rare, as it occurs in one to five persons per million population in any given year in the United States. It is equally diagnosed in both adults and children. TM may occur by itself or in conjunction with other illnesses such as viral or bacterial infectious diseases, autoimmune diseases such as multiple sclerosis, vascular illnesses such as thrombosis, and cancer.

The symptoms of TM depend on the level of spinal cord lesion with sensation usually diminished below the spinal cord level affected. Some patients experience tingling sensations or numbness in the legs with bladder control also being disturbed. The condition is usually diagnosed following magnetic resonance imaging (MRI) or computed tomography (CT) with "spinal taps" (lumbar punctures) taken for additional analysis. Recovery depends on the general health status of the patient and is usually considered unlikely if no improvement is observed within three months.

Causes

The exact cause of TM is unknown but research results point to autoimmune deficiencies, meaning that the patient's own immune system abnormally attacks the spinal cord, resulting in inflammation and tissue damage.

There is also evidence suggesting that TM occurs as a result of spinal cord compression by tumors or as a result of direct spinal cord invasion by infectious agents, especially the human immunodeficiency virus (HIV) and the human T-lymphotropic virus type I (HTLV-1).

TM is also listed among the spinal cord disorders occurring in patients diagnosed with AIDS.

Treatments

There is no specific treatment for transverse myelitis. Treatment of the illness is largely symptomatic, meaning that it depends on the specific symptoms of the patient. The region in which the spinal cord has been infected is critical but a course of intravenous steroids is generally prescribed at the onset of treatment.

Treatment of the bladder function impairment resulting from TM include drugs, external catheters for men and padding for women, with surgery recommended in certain cases. A common TM side effect is difficulty with stool evacuation and this condition can be treated by diets that include stool softeners and fiber.

As a result of TM, muscle groups below the affected level may become spastic. Treatment of spasticity usually involves prescriptions of drugs such as Baclofen (Lioresal), which stops reflex activity, and Dantrolene sodium (Dantrium) which acts directly on muscle. A new very well-tolerated drug, Tizanidine, has also recently been introduced in the United States. Muscle pain is generally treated with analgesics such as acetaminophen (Tylenol) or ibuprofen (Naprosyn, Aleve, Motrin). Nerve disorders might be treated with anticonvulsant drugs such as carbamazepine , phenytoin or gabapentin (Tegretol, Dilantin, Neurontin).

Alternative and complementary therapies

Individuals with TM may experience serious difficulty with common tasks such as dressing, bathing and eating. Complementary TM therapies may accordingly include a course of physical therapy so as to help patients recover mobility. This can be achieved with special exercises, canes, walkers and custom-designed braces.

After the acute phase, people with TM start the rehabilitation process. During this period, the focus of care is shifted from designing an effective TM treatment to learning to cope with a serious disease. TM patients must learn to cope with the loss of abilities which healthy people take for granted and this process is necessarily harder if TM is associated with AIDS or another serious autoimmune disease. Resources that may help this required adjustment are psychological assistance from counselors, relatives and friends, and making contact with TM support groups. The Transverse Myelitis Association may also be contacted: 3548 Tahoma Pl. West, Tacoma, WA 98466-2141 ([email protected]; www.myelitis.org) Phone:253-565-8156.

See Also Imaging studies; Lumbar puncture

Resources

BOOKS

Beers, M.H., and R. Berkow, eds. The Merck Manual of Diag nosis and Therapy, 17th ed. Whitehouse Station, NJ:Merck Research Laboratories, 1999.

ORGANIZATIONS

Transverse Myelitis Association. 3548 Tahoma Pl. West, Tacoma, WA 98466-2141. (253) 565-8156. <http://www.myelitis.org>.

National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health. NIH Neurological Institute. P.O. Box 5801, Bethesda, MD 20824. (800) 352-9424. <http://www.ninds.nih.gov>.

Monique Laberge, Ph.D.

KEY TERMS

Autoimmune disease

—An illness which occurs when the body tissues are attacked by its own immune system. The immune system is a complex defense mechanism of the body whose primary function is to seek out and destroy invaders of the body, especially infections.

Catheter

—A tubular, flexible instrument used to withdraw fluids from a body cavity, especially urine from the bladder.

Infectious disease

—A disease caused by a virus or a bacterium. Examples of viruses causing an infectious disease are: HIV-1 virus, herpes simplex, cytomegalovirus, Epstein-Barr virus, leukemia virus. Examples of bacterial infectious diseases are: syphilis and tuberculosis.

Spinal cord

—Elongated part of the central nervous system of vertebrates that lies in the vertebral canal and from which the spinal nerves emerge.

Spinal cord compression

—A condition resulting from pressure being applied on the spinal cord, as from a tumor or spinal fracture. Depending on the location of the pressure, symptoms may include pain, numbness, tingling and prickling sensations as well as lock of sensory or motor functions.

Spinal tap

—A diagnostic procedure by which a needle is introduced into the lower spine to collect cerebrospinal fluid for diagnostic testing.

Transverse Myelitis

Definition

Transverse myelitis (TM) is an uncommon neurological syndrome caused by inflammation (a protective response which includes swelling, pain, heat, and redness) of the spinal cord, characterized by weakness, back pain, and bowel and bladder problems. It affects one to five persons per million.

Description

TM affects the entire thickness of the spinal cord, producing both sensory and movement problems. It is believed to be linked to the immune system, which may be prompted to attack the body's own spinal cord. Striking rapidly without warning, its effects can be devastating.

Causes and symptoms

Transverse myelitis has many different causes, often triggered by a variety of viral and bacterial infections (especially those associated with a rash such as measles or chickenpox ). Once the infection subsides, the inflammation in the cord begins. About a third of patients experience a flu-like illness with fever about the time they develop symptoms of TM. Sometimes, there appears to be a direct invasion of, and injury to, the spinal cord by an infectious agent (such as herpes zoster or the AIDS virus).

TM can also accompany a variety of diseases that break down tissue that surrounds and insulates the nerves (demyelinating diseases), such as multiple sclerosis (MS).

Some toxic substances, such as carbon monoxide, lead, or arsenic, can cause a type of myelitis characterized by inflammation followed by hemorrhage or bleeding that destroys the entire circumference of the spinal cord. Other types of myelitis can be caused by poliovirus; herpes zoster; rabies, smallpox or polio vaccination; or parasitic and fungal infections.

Many experts believe that TM can occur without any apparent cause, probably as the result of an autoimmune process. This means that a person's immune system attacks the spinal cord, causing inflammation and tissue damage.

Regardless of the cause of the myelitis, onset of symptoms is sudden and rapid. Problems with movement and sensation appear within one or two days after inflammation begins. Symptoms include soft (flaccid) paralysis of the legs, with pain in the lower legs or back, followed by loss of feeling and sphincter (muscles which close an opening, as in the anus) control. The earliest symptom may be a girdle-like sensation around the trunk.

The extent of damage occuring will depend on how much of the spinal cord is affected, but TM rarely involves the arms. Severe spinal cord damage also can lead to shock.

Diagnosis

A doctor will suspect transverse myelitis in any patient with a rapid onset of paralysis. Medical history, physical examination, brain and spinal cord scans, myelogram, spinal tap, and blood tests are used to rule out other neurological causes of symptoms, such as a tumor. If none of these tests suggest a cause for the symptoms, the patient is presumed to have transverse myelitis.

Treatment

There is no effective treatment for transverse myelitis, but any underlying infection must be treated. After this, the focus of care shifts from diagnosis and treatment to learning how to live with the effects of the syndrome. Patients are helped to cope psychologically with new limitations, and are given physical rehabilitation.

Physical adaptations include learning to cope with bowel and bladder control, sexuality, inability to control muscles (spasticity), mobility, pain, and activities of daily living (such as dressing).

As nerve impulses from the spinal cord are often scrambled and misinterpreted by the brain as pain, painkillers are given to ease discomfort. Antidepressants or anticonvulsants may also help.

Prognosis

The prognosis depends on how much of the cord was damaged. Some people recover completely, while others have lasting problems and need help in learning how to cope with activities of daily living. People who develop spastic reflexes early in the course of the condition are more likely to recover than those who do not. If spinal cord tissue death (necrosis) occurs, the chance of a complete recovery is poor. Most recovery occurs within the first three months. A certain percentage of patients with TM will go on to develop multiple sclerosis.

Resources

ORGANIZATIONS

Transverse Myelitis Association. 1787 Sutter Parkway, Powell, OH 43065-8806. (614) 766-1806. 〈http://www.myelitis.org〉.

KEY TERMS

Demyelinating disorders— A group of diseases characterized by the breakdown of myelin, the fatty sheath surrounding and insulating nerve fibers. This breakdown interferes with nerve function, and can result in paralysis. Multiple sclerosis is a demyelinating disorder.

Myelogram— An x-ray examination of the brain and spinal cord with the aid of a contrast dye, to look for tumors or spinal cord injury.