Making sense of multiple sclerosis
Although a once-promising MS drug has been pulled off the market, other therapies are under investigation.
Every week, about 200 Americans, most of them women, discover that they have multiple sclerosis (MS), a chronic, incurable neurological disease. For many, the bad news begins with a bout of subtle but scary symptoms, which can include tingling sensations, muscle weakness, and blurred or double vision. These symptoms usually wax and wane, reappearing unpredictably after months or even years. Some MS patients are only mildly affected; others eventually need a cane, wheelchair, or human assistance to get around. Aside from the physical challenges of the disease, uncertainty about its course often fosters depression and stress.
Early in 2005, the hopes of many MS patients (and their friends and families) were dashed when Tysabri — a drug shown to prevent relapses better than other currently available therapies — was linked to a very rare, often fatal brain disease. As a result, the manufacturers, Biogen Idec and Elan, suspended marketing. Now, researchers are trying to understand why Tysabri, which blocks certain immune cells from entering the brain, is so helpful to some and so dangerous to others. (Some experts believe it will eventually return to the market, with expanded warnings and restrictions.) Progress is also being made in understanding what causes the disease, predicting its course, and developing new therapies.