Cleveland clinic zeroes in on factors that block natural myelin repair. (News).

The human body is, generally, amazingly resilient. It has, even in old age, the capacity to heal a wide range of damage from injury or disease.

With this in mind, Cleveland Clinic investigators, headed by Drs. Ansi Chang and Bruce Trapp, searched for evidence of repair of nerve-insulating myelin in 48 "chronic" MS brain lesions (long-standing patches of myelin damage that show little sign of active immune attack). The lesions were taken from tissue donations of 10 individuals. The findings, published in the January 17, 2002 issue of The New England Journal of Medicine, provide strong evidence that the brain makes major attempts to repair itself.

The Cleveland Clinic investigators found an abundance of myelin-making cells, called oligodendrocytes, in 34 of the 48 lesions examined--no matter how old the person was or what type of MS she or he had had. Even more interesting, the appearance and condition of the oligodendrocytes suggested that the cells had tried but were unable to complete the final steps needed to replace myelin. The oligodendrocytes had sent their characteristic octopus-like arms down toward nerve fibers and showed signs of myelin production, but they failed to wrap new myelin around the fibers.

The investigators believe that nerve fibers within chronic lesions somehow create conditions unfavorable to myelin replacement. Additional research may lead to therapies that will push the myelin-making cells into the final stages of repair. These and many other approaches to repairing MS damage are under investigation.