January 29, 2001
Alzheimer's disease and other serious brain disorders that occur mainly in older people get constant attention. Multiple sclerosis (MS), the most common nerve disease in younger people, gets all too little.
But awareness of MS is becoming more important. MS starts with vague symptoms that often are ignored, dismissed as "just your imagination," or diagnosed as something else. Until a few years ago, it made little difference because doctors couldn't do much to help people with early MS.
That situation is changing, thanks to a new generation of so-called disease-modifying drugs. These medicines - Avonex, Betaseron, and Copaxone - offer hope of holding MS symptoms at bay, sparing patients from expensive medical complications and disability that often occur with MS.
A major study last year found that early drug treatment with Avonex reduced the risk of developing more advanced MS by almost 50 percent. Researchers who did the study suggested that patients have a magnetic resonance imaging (MRI) brain scan to see whether their symptoms are MS. Then patients and doctors should make a decision on drug therapy.
MS is a real-life medical mystery, on several counts.
Nobody knows exactly how many people have it. An estimated 250,000 to 350,000 people in the United States have been diagnosed. Cost to the economy: More than $2.5 billion annually. Thousands of other people have early or mild symptoms, but no diagnosis.
Mysteriously, MS is five times more common among people living in northern areas of the United States, Canada, and Europe. Age 15 is critical in deciding an individual's risk. A person moving from a high-risk northern area to a southern area before age 15 adopts the low risk of the new area. A person moving from the south to the north adopts the high risk. People moving after age 15 keep the risk of their original area.
Do people in the north encounter some agent in the environment that depends on cold winters? Is there some protective factor in the environment in low-risk areas? Do teenagers somehow catch a slow-acting virus that takes years to produce symptoms?
People with MS usually have their first symptoms between age 20 and 40. They often include blurred or double vision, red-green color distortion, or blindness in one eye. Among the other early symptoms are muscle weakness and difficulty with balance, coordination, and walking; numbness or "pins-and-needles" sensations; dizziness; speech disturbances; muscle spasms, and fatigue.
The symptoms occur because MS damages the fatty covering on nerve cells in the brain and spinal cord. Called myelin, it insulates nerve cells much like plastic insulation on an electric power cord.
With their myelin damaged, nerve cells can't properly transmit the messages that control muscle movement and other body functions.
Symptoms may occur in combinations, be mild or severe, and often develop over several days and then disappear. Heat from warm outdoor temperatures, hot baths or showers, or exercise often makes them worse.
The most common kind of MS is called relapsing-remitting multiple sclerosis because patients have periods of symptoms, or "relapses," followed by "remissions," or symptom-free periods.
Some patients have a mild form of MS in which symptoms never get worse. Many others, however, experience increasing loss of mobility and severe disability.
The National MS Society in 1998 recommended starting treatment with one of the three new drugs right after diagnosis. Yet the organization says that many patients are not getting early treatment. The main reasons: Doctors and patients often are unaware of the benefits, and patients may lack insurance coverage for the drugs, which can cost $10,000 annually.
People with MS symptoms should get a definite diagnosis, and talk with their doctors about the new drugs.
Michael Woods is
the Blade's science editor. Email him at email@example.com.