More MS news articles for Jan 2002

Multiple sclerosis rising among US women: report

NEW YORK, Jan 18 (Reuters Health) - The number of US women living with multiple sclerosis (MS) appears to have risen over the past two decades, according to researchers at the US Centers for Disease Control and Prevention (CDC).

National survey data indicate that among women, the number of MS cases increased 50% between 1982 and the mid-1990s--from 75 cases per 100,000 women to 113 per 100,000. No such trend occurred among men, who in general have lower rates of MS compared with women.

The reason is unclear, but the pattern among women may be due to an increased rate of new MS cases, better diagnosis, improved treatment that is allowing patients to live longer, or all of the above, the investigators report in the January issue of Neurology.

Dr. Curtis W. Noonan and his colleagues at the Atlanta, Georgia-based CDC analyzed US survey data to determine how many Americans were living with MS as of 1996. Various US studies, they note, have placed MS prevalence anywhere between 39 and 173 cases per 100,000 people.

Their findings indicate 85 MS cases per 100,000 people--or about 211,000 Americans.

One reason it is important to establish MS prevalence is so investigators can get a better handle on reports of "cluster" cases of the disease. Noonan's team notes that residents of several communities living near hazardous waste sites have expressed concern over what they see as a high number of MS cases in their area. Scientists periodically get reports of MS clusters, but no environmental toxin has yet been identified as a cause of the disease.

And to determine what a truly "high" prevalence is, health officials need to know roughly how many MS cases should be expected in a given population, the researchers point out. Before this study, the most recent national MS figures broken down by age and race/ethnicity were from 1976.

Noonan's team found that for both men and women, MS prevalence was highest among adults in their 40s and 50s, in agreement with what is known about MS. The disease was more common among white women compared with women of other races, and geographically, prevalence was lowest in the South--again in agreement with past research.

The rising prevalence among women has also been suggested in other studies, the authors note.

No one knows what causes MS, a disease that occurs when the protective myelin sheath surrounding nerve fibers in the brain and spine is slowly destroyed. This causes symptoms such as muscle weakness and stiffness, balance and coordination problems, numbness and vision disturbances.

Scientists believe that an abnormal immune system attack is behind the myelin destruction, but the trigger is unknown. One possibility is that genetics conspire with environmental factors such as viruses or toxins to trigger the aberrant immune response.

SOURCE: Neurology 2002;58:136-138.

Copyright © 2002 Reuters Limited