Multiple sclerosis is a disorder of the brain and spinal cord (central nervous system) caused by progressive damage to the outer covering of nerve cells (myelin). This results in decreased nerve functioning, which can lead to a variety of symptoms.
Causes, incidence, and risk factors
The cause of MS is unknown. The disease involves repeated episodes of inflammation of nervous tissue in any area of the central nervous system (brain and spinal cord). These episodes occur when the body’s own immune cells attack the nervous system.
The location of the inflamed areas varies from person to person and from episode to episode. The inflammation destroys the covering of the nerve cells (myelin sheath) in that area, leaving multiple areas of scar tissue (sclerosis). This results in slowing or blocking of the transmission of nerve impulses in that area, leading to the symptoms of MS.
Symptoms vary because the location and extent of each attack varies. There is usually a stepwise progression of the disorder, with episodes that last days, weeks, or months alternating with times of reduced or no symptoms (remission). Recurrence (relapse) is common although non-stop progression without periods of remission may also occur.
The exact cause of the inflammation associated with MS is unknown. Geographic studies indicate there may be an environmental factor involved. MS is more likely to occur in northern Europe, the northern United States, southern Australia, and New Zealand than in other areas.
The “intertropical belt” seems to have much lower rates of this condition. There seems to be a genetic link to the disease, with some families more likely to be affected than others and certain genetic markers are more common in people with MS than in the general population.
An increase in the number of immune cells in the body of a person with MS indicates that there may be a type of immune response that triggers the disorder. The most frequent theories about the cause of Multiple sclerosis include a virus-type organism, an abnormality of the genes responsible for control of the immune system, or a combination of both factors.
Multiple sclerosis (MS) affects approximately 1 out of 1,000 people. More women are affected than men. The disorder most commonly begins between ages 20 and 40, but can strike at any age. Risks include a family history of MS and living in a geographical area with a higher incidence rate for MS.
- weakness of one or more extremities
- paralysis of one or more extremities
- tremor of one or more extremities
- muscle spasticity (uncontrollable spasm of muscle groups)
- muscle atrophy
- movement, dysfunctional - slowly progressive; beginning in the legs
- numbness or abnormal sensation in any area
- facial pain
- extremity pain
- loss of vision - usually affects one eye at a time
- double vision
- eye discomfort
- uncontrollable rapid eye movements
- eye symptoms worsen on movement of the eyes
- decreased coordination
- loss of balance
- decreased ability to control small or intricate movements
- walking/gait abnormalities
- muscle spasms (especially in the legs)
- urinary hesitancy, difficult to begin urinating
- strong urge to urinate (urinary urgency)
- frequent need to urinate (urinary frequency)
- incontinence (leakage of urine, loss of control over urination)
- decreased memory
- decreased spontaneity
- decreased judgment
- loss of ability to think abstractly
- loss of ability to generalize
- decreased attention span
- slurred speech
- difficulty speaking or understanding speech
- fatigue, tired easily
Additional symptoms that may be associated with this disease:
- hearing loss
- positive Babinski’s reflex
Note: Symptoms may vary with each attack. They may last days to months, then reduce or disappear, then recur periodically. With each recurrence, the symptoms are different as new areas are affected. Fever can trigger or worsen attacks, as can hot baths, sun exposure, and stress.
Signs and tests
Symptoms of MS may mimic many other neurologic disorders. Diagnosis is made by ruling out other conditions.
A history of at least two attacks separated by a period of reduced or no symptoms may indicate one pattern of attack/remission seen in MS (known as relapsing remitting pattern). If there are observable decreases in any functions of the central nervous system (such as abnormal reflexes), the diagnosis of MS may be suspected.
Examination by the health care provider may show focal neurologic deficits (localized decreases in function). This may include decreased or abnormal sensation, decreased ability to move a part of the body, speech or vision changes, or other loss of neurologic functions. The type of neurologic deficits usually indicates the location of the damage to the nerves.
Eye examination may show abnormal pupil responses, changes in the visual fields or eye movements, nystagmus (rapid eye movements) triggered by movement of the eye, decreased visual acuity, or abnormal findings on a fundoscopy (an examination of the internal structures of the eye).
Tests that indicate or confirm Multiple sclerosis include:
- head MRI scan that shows scarring or a new lesion
- spine MRI scan that shows scarring or a new lesion
- lumbar puncture (spinal tap)
- CSF oligoclonal banding
- CSF IgG index
There is no known cure for Multiple sclerosis at this time. However, there are promising therapies that may delay progression of the disease. Treatment is aimed at controlling symptoms and maintaining function to give the maximum quality of life.
Patients with a relapsing-remitting course are placed on immune modulating therapy that requires injection under the skin or in the muscle once or several times a week. This may be in the form of interferon (such as Avonex or Betaseron) or another medicine called glatiramer acetate (Copaxone). They are all similar in their effectiveness and the decision on which to use depends on concerns about particular side effects.
Other than protective therapies, steroids are given to decrease the severity of attacks when they occur. These shut the immune system down to stop cells from causing inflammation. Other medicines such as lioresal (Baclofen), tizanidine (Zanaflex), or one of the benzodiazepines may be used to reduce muscle spasticity. Cholinergic medications may be helpful to reduce urinary problems. Antidepressant medications can also help with mood or behavior symptoms. Amantadine may be given for fatigue.
Physical therapy, speech therapy, occupational therapy, and support groups may also be useful. These can help improve the person’s outlook, reduce Depression, maximize function, and improve coping skills. A planned exercise program early in the course of the disorder can help with maintaining muscle tone.
A healthy lifestyle is encouraged, including good general nutrition. Adequate rest and relaxation can help maintain energy levels. Attempts should be made to avoid fatigue, stress, temperature extremes, and illness to reduce factors that may trigger an MS attack.
For additional information, see Multiple sclerosis resources.
The outcome is variable and unpredictable. Although the disorder is chronic and incurable, life expectancy can be normal or nearly so. Most people with MS continue to walk and function at work with minimal disability for 20 or more years.
The factors felt to best predict a relatively benign course are female gender, young age at onset (less than 30 years), infrequent attacks, a relapsing-remitting pattern, and low burden of disease on imaging studies.
The amount of disability and discomfort varies with the severity and frequency of attacks and the part of the central nervous system affected by each attack. Commonly, there is initially a return to normal or near-normal function between attacks. As the disorder progresses, there is progressive loss of function with less improvement between attacks.
- progressive disability
- Urinary tract infections
- side effects of medications used to treat the disorder
Calling your health care provider
Call your health care provider if you develop any symptoms of MS, as he or she is the only one who can distinguish Multiple sclerosis from other serious disorders such as Stroke or infection.
Call your health care provider if symptoms progressively worsen despite treatment.
Call your health care provider if the condition deteriorates to the point where home care is no longer possible.
by Mamikon Bozoyan, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.