For the vast majority of people, myelin repair occurs as a result of a series of natural processes. Specialized cells known as Schwann cells repair damage to myelin in both the central and peripheral nervous systems. There are not currently any medical treatments that can assist in myelin repair, although scientists have been conducting research for many years in order to discover potential treatments for patients who have demyelinating diseases.
In patients without demyelinating diseases, myelin repair occurs naturally in both the central and peripheral nervous system. Repair begins when a gene sends the body instructions to create the proteins that myelin is made up of. Once these proteins have been synthesized, Schwann cells coat nerve axons with them in order to repair damage on the myelin sheath.
Schwann cells maintain the myelin sheaths on all nerve cells. Over time, myelin naturally degenerates, but it is quickly repaired under normal circumstances. Schwann cells are able to repair normal wear and tear and even serious damage to the myelin sheaths, especially those in the peripheral nervous system. A completely severed peripheral nerve can sometimes regenerate after the myelin sheath is restored.
Medical myelin repair is focused on introducing replacement cells that repair myelin sheaths. It is not possible to repair these sheaths through other means. The number of nerves in the nervous system and the size of these nerves makes it impossible to repair them individually, so patients must, in one way or another, make these repairs themselves.
Stem cells are believed to be a possible way to medically stimulate myelin repair. Serious injuries of the central nervous system have been reversed in animals that were treated with the use of these cells. Stem cells can be taken from the nervous system of fetuses, bone marrow, and umbilical cord blood and are able to adapt to the needs of the host. A host lacking Schwann cells may generate new ones out of these stem cells. Though research on human patients is in it's infancy, scientists are hopeful that this type of treatment might result in a reversal of demyelinating diseases such as multiple sclerosis.
Another way medicine might assist with myelin repair is to alter the chemical messengers in a patient's body. In some patients with demyelinating diseases, the loss of myelin is caused when the body instructs cells, such as Schwann cells, to die off. Sending a patient chemical instructions to create more of these cells is one potential way to improve the patient's natural myelin repair.