multiple sclerosis
ABBR: MS
A chronic disease of the central nervous system (CNS) in which there is destruction of myelin within several regions of the brain and spinal cord at different times. This results in temporary, repetitive, or sustained disruptions in nerve impulse conduction, causing symptoms such as muscular weakness, loss of coordination, numbness, visual disturbances, loss of control of bowel, bladder, and sexual functions. The clinical picture in MS depends upon the extent of demyelination. SYN: insular sclerosis.
Incidence: Multiple sclerosis is a relatively common disorder: more than 400,000 Americans are affected, of whom the majority (about 390,000) are adults. Multiple sclerosis usually begins between ages 20 and 40; women are three times likelier than men to contract the disease, and European Americans are more likely to be affected than African Americans or Asian Americans.
Causes: The cause of the disease is unknown although much evidence suggests that T lymphocytes that injure nerve cells and nerve sheaths play an important role, i.e., that the disease has an autoimmune basis. Considerable evidence links MS to low levels of vitamin D, a history of smoking, Epstein-Barr virus infection, or genetic susceptibility. MS occurs most commonly at higher latitudes, and is rare in the tropics.
Symptoms and Signs: Nearly a quarter of all patients with MS initially develop visual disturbances or blindness. Other consequences of the disease include sudden or progressive weakness in one or more limbs, muscular spasticity, nystagmus, fatigue, tremor, gait instability, recurrent urinary tract infections (caused by bladder dysfunction), incontinence, and alterations in mood, including euphoria, irritability, and depression.
SEE: retrobulbar neuritis.
Four main categories of MS are currently recognized. The benign variant is marked by several episodes of nervous system dysfunction, followed by complete recovery. The primary progressive variant is marked by rapid loss of neurological functions that do not resolve, causing severe functional impairments that worsen over time. More common than either of these types of MS are the two relapsing-remitting variants. In patients with these disorders, neurological deficits develop and then improve either completely or partially. In patients who achieve only partial restoration of neurological function, secondary progression of the disease may result in a gradual accumulation of visual, motor, or sensory disabilities.
Diagnosis: Diagnosis is usually based on the patient’s history and brain imaging. In a person who has two or more neurological symptoms separated in time, and two different areas of the brain with enhancing lesions appearing at two different times, the diagnosis is established. Lumbar puncture may also be performed to assess patients for oligoclonal band s (immunoglobulins released into the cerebrospinal fluid due to inflammation).
Treatment: Acute treatment consists of giving high-dose corticosteroids. For patients who don’t respond, plasma exchange, or induction chemotherapy with cytoxan, may be necessary.
Maintenance therapy is then given to decrease the likelihood of new neurological symptoms and new brain lesions. This may consist of injectable agents, such as beta interferons, glatimer acetate (given subcutaneously), oral drugs (such as the sphingosine 1-phosphate (S1P) receptor modulator fingolimod, or dimethyl fumarate), or monoclonal antibody therapies (such as ocrelizumab).
Impact on Health: About half of all patients with MS become unable to work within 10 to 15 years of the first onset of symptoms. Within 25 years of the first symptoms, half of these patients cannot walk.
Patient Care: The health care professional provides support to patients with MS and their families. The patient is advised to avoid fatigue, overexertion, exposure to extreme heat or cold, and stressful situations, and is encouraged to follow a regular plan of daily activity and exercise based on levels of tolerance. The patient is taught about symptoms that may occur during exacerbations of the disease and the need to adapt the plan of care to changing needs and about the administration of prescribed medications. Physical and occupational therapy help the patient to maintain muscle tone and joint mobility, decrease spasticity, improve balance and coordination, and increase morale. Massages, relaxing baths, yoga, and tai chi may prove helpful. A nutritious, well-balanced diet with adequate roughage and fluids is recommended. Bladder and bowel training programs, self-catheterization, and the use of condom catheters may be required. Independence is encouraged by assisting the patient to develop new methods for activities of daily living (ADL) performance and optimal functioning. Both the patient and family are encouraged to promote safety in the home and the work environment. For support and information, the patient and family should be referred to the National Multiple Sclerosis Society. Telephone: 800-FIGHT-MS; Website: www.nmss.org