http://www.reutershealth.com/archive/2002/01/24/eline/links/20020124elin018.html

By Keith Mulvihill

NEW YORK, Jan 24 (Reuters Health) - Polish scientists report that they have detected very subtle brain changes in healthy relatives of patients with multiple sclerosis (MS), which the researchers say may predispose these individuals to developing MS themselves.

"In brains of relatives of MS patients, there are subtle molecular changes similar to those occurring in the brains of patients, which we were unaware of before," lead investigator Dr. Krzysztof Selmaj, of the Medical Academy of Lodz, told Reuters Health in an interview.

"We have known previously that relatives of MS patients have a moderately increased risk to get MS but the reason for that was unknown," he added. "Our results suggest that in brains of relatives there are changes which make them more susceptible to get MS."

No one knows what causes MS, which occurs when the body's immune system mistakenly attacks the protective myelin sheath surrounding nerve fibers in the brain and spine. Symptoms of MS include muscle weakness and stiffness, balance and coordination problems, numbness and vision disturbances.

Using a technique called magnetization transfer imaging (MTI), the researchers scanned the brains of 30 people who had a sibling, child or parent with MS. These scans were compared with brain scans of MS patients and healthy volunteers.

MTI is a new technique that measures the integrity of molecules in the brain, according to Selmaj. Using magnetics, it can pick up very subtle changes in the structure of the myelin sheath that cannot be seen with other brain scans, he explained.

Although half of the people in the study had relatives with familial MS and the other 15 had relatives with sporadic MS--meaning that there was no family history of the disease--the brains of people in both groups had the subtle brain changes, Selmaj and colleagues report in the February issue of the journal Neurology.

"MS is a very serious disease and it seems that the genetic component of it is more important than we thought earlier," he told Reuters Health.

Since relatives of MS patients have a higher risk of developing the disease, Selmaj's team hopes that the new findings will provide further information about what causes MS.

Scientists are not clear what triggers the abnormal immune system attack involved in MS. One possibility is that genetics interact with environmental factors such as viruses or toxins to trigger the aberrant immune response.

For the time being, Selmaj does not recommend that relatives of MS patients undergo brain scans to see if they have brain changes.

"Before that, we should find a firm answer to the question of how often these subtle changes will transfer to fully developed MS," he said.

SOURCE: Neurology 2002;58:317-320.
 

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