A new study conducted by researchers at Mayo Clinic showed considerable differences of tissue damage depending on the stage of multiple sclerosis. The researchers found out that plaques or the areas where the nervous system is inflamed or demyelinated seem to be predominantly active and show distinct heterogeneous patterns of myelin damage during the early relapsing stages of MS. However, smoldering or inactive plaques are seen more and characterized by uniform pattern of tissue damage on the latter chronic progressive stage of the said disease.
The observations that the said study showed may provide researchers with important information concerning the dynamic changes happening to plaques on various stages of the disease. Active plaques are those that are newly formed and with myelin undergoing continuous damage. Smoldering plaques may bring about a limited degree of myelin damage . Inactive plaques on the other hand show no further evidence of myelin breakdown.
The said study involved studying tissue fro autopsies of 143 individuals suffering from multiple sclerosis. The analyzed tissues showed over 2,479 plaques that were classified as either active, smoldering or inactive. The team of researchers found out that the tissue damage that occur changes over the duration of the disease. Early in the disease, numerous active plaques are usually identified. In the latter stages these active plaques as well as the diverse patterns of myelin damage patterns become less and less common.
According to Claudia Luccinetti M.D., a Mayo Clinic neurologist and author of the study, there may be a low likelihood of having any active plaques if the disease has gone beyond 20 years. What is found is a predominance of inactive and smoldering plaques that show a uniform pattern of tissue injury.
"We recognize that there’s not just one therapy that works for everyone with MS; patients already know this. We need to better understand why that might be, study it, model it in the laboratory, and then hopefully translate it into something that makes a difference in patients’ lives," adds Dr. Lucchinetti.