Monday, May 11, 2009

World MS Day is May 27th

Who Gets MS?

Multiple Sclerosis, or MS, is a chronic and often disabling autoimmune condition that strikes the central nervous system. Although men can get MS, it most often strikes women who are in the prime of life, typically those from 20 to 50 years of age.

Genetics and the environment are both thought to play a role in the development of MS. A familial tendency has been demonstrated, with persons of Northern European heritage being more likely to develop MS. Even living farther from the equator (and therefore being exposed to less sunlight) is a theory. (And it's a compelling one--I sure didn't see much MS in the desert Southwest, while I was astonished at the number of MS patients here in Central Illinois. Of course, few of my patients in the desert were of Northern European heritage . . .)

Having a tendency towards this autoimmune condition is only one part of the puzzle, however. Ultimately, there must be some "last straw" that triggers the immune system to damage the body that it is supposed to protect. (Theories about "the last straw" that triggers autoimmune responses often vaguely suggest that some type of viral infection may be to blame.)

Central Nervous System is Affected by MS

We've already established that Multiple Sclerosis affects the central nervous system. The brain and spinal cord are the major players in this system. They send out signals that communicate with the rest of the body to control every function--even ones we aren't consciously aware of.

Neurons are specialized cells that transmit information from the brain and spinal cord to the rest of the body. Most neurons have a protective, insulating covering which is called myelin. In MS, the immune system damages the myelin covering (often called the myelin sheath), causing the portion of the nerve cell underneath it to become exposed to injury and permanent damage.

(I always like to paint a picture in my mind to help me "see" physiological concepts as a simple analogy. In this case, think about roller skating across a smooth, flat varnished floor all the way from point A to point B. Easy right? Now imagine roller skating across that same surface--except now between point A and point B, a segment of the varnished floor has been stripped away, leaving rough gravel in your path. That kind of gives you an idea of how the "message" a nerve is transmitted becomes halted in its course when the myelin sheath is disrupted along a nerve path.)

Clinical Stages of MS

Symptoms of MS vary from one person to the next and may be as mild as numbness and tingling in the limbs, or as severe as paralysis or loss of eyesight. The progression of the disease and its severity are likewise impossible to predict with certainty. Several distinct clinical stages of MS have been recognized and are useful in guiding treatment decisions.

  • Relapsing-remitting: Symptoms come and go. During periods of relapse, inflammation of the myelin sheath causes MS symptoms that ultimately resolve (they may resolve completely or their may be some residual symptoms that persist).
  • Secondary progressive: There may still be some periods of remission, but this phase shows a steady progress of nerve degeneration and physical deterioration. The nervous system has been damaged enough so that there isn't the ability to bounce back as with relapsing-remitting MS.
  • Progressive relapsing: This is the least common type of MS. In this case, the symptoms progress from the very beginning without the benefit of remission. On the contrary, the progression of the symptoms are punctuated by periods of relapse in which the neurological function actually temporarily worsens.
  • Primary progressive: A gradual and continual progression of symptoms is the hallmark of this type of MS. The course of this type of MS doesn't include periods of relapse or remission.

Treatments for MS

Check out the National MS Society website for comprehensive information on treatments for MS. Like other autoimmune diseases, there is no cure yet for MS, but there are a number of treatment options and strategies designed to slow disease progression, treat relapses, manage and control symptoms, and improve physical function and enhance safety.

Recommended reading:

National Institute of Neurological Disorders and Stroke: Multiple Sclerosis

MS Overview from WebMD

MS tutorial from medlineplus

National MS Society

Mayo Clinic article about MS and remyelinization

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