Study finds similarities in different forms
Thursday November 16 03:06 AM EST
By Edward Edelson
WEDNESDAY Nov. 15 (HealthScout) -- A European study adds another piece to one of the most puzzling of all diseases -- multiple sclerosis, which causes progressive deterioration of the nerves in the brain and spinal cord.
"We've been getting a number of interesting studies over the past year, and there is a feeling that there might perhaps be different subtypes of multiple sclerosis," says Dr. Patricia A. O'Looney, director of biomedical research for the National Multiple Sclerosis Society.
MS attacks the nervous system with an inflammation that damages myelin, the delicate substance that coats and protects nerve cells. Some axons -- nerve cells -- may also die. MS is the most common disease of the nervous system, affecting 250,000 to 300,000 Americans, with 10,000 new cases each year.
The disease usually begins in the early adult years, and can follow different courses in different patients. In some, there is steady, progressive damage to the nervous system. But in the great majority, about 85 percent of patients, the progression of the disease is halted by remissions, which are followed by relapses. But in some of these remission-relapse patients, the damage becomes progressive after 10 or 15 years, when remissions end.
The European study, reported in The New England Journal of Medicine by the European Database for Multiple Sclerosis Coordinating Center in Lyons, France, says that whatever form the disease takes, the results are the same: "Relapses do not significantly influence the progression of irreversible disability." That finding is based on the decade-long clinical experience of more than 1,800 patients.
"There have been many unanswered questions about the different courses that a person with MS might follow, how the relapse rate is related to nervous system degeneration and axon loss," O'Looney says. "This is additional information adding to the need to understand more about the relationship between inflammation, loss of myelin and loss of axons."
MS is an autoimmune disease, in which the immune system somehow attacks the body's own tissue. "The immune system appears to be turned on in genetically susceptible individuals," O'Looney says. But geography also plays a role. MS is rarely found in the tropics and is more common in temperate zones, such as the United States and Europe. And there is a long-standing suspicion that the underlying cause is an infection.
"Something triggers MS," O'Looney says. "That trigger is probably some sort of virus or bacterial agent. For 50 years we have been trying to identify what that agent may be, and the search goes on."
While that search goes on, one important objective is to determine the exact relationship between inflammation and the attack on the nervous system, says Dr. W. Ian McDonald of the Royal College of Physicians in London, author of an accompanying editorial. Right now, he says, the picture is "confusing."
"Acute relapse is essentially an inflammatory event," he says. "Until the relationship between inflammation and degeneration is clarified, it will be difficult to arrive at a coherent picture of the relationship between the pathology and the clinical evolution of the disease."
Treatment now is aimed essentially at interfering with the immune system attack on the nervous system with drugs such as interferon and corticosteroids. Learning more about the way that inflammation causes nerve damage can help develop new treatments, McDonald says.
What To Do
MS can be frustrating and disheartening, but the most important thing to do is talk to your doctor if you think you may have it. The sooner you are treated, the better off you will be.
To find out more about the disease, including symptoms, where to go
for help and much, much more, check out the National
Multiple Sclerosis Society or the MS