Myelin is the fatty covering that insulates and protects nerve cells. It is critical to normal function of the central nervous system (CNS). By insulating and protecting nerve fibers, myelin allows the rapid conduction of electrical impulses in the brain and spinal cord. Those electrical impulses transmit messages to and from muscles, sensory organs and thought centers. When myelin is damaged, conduction of impulses along axons (the part of a nerve cell that sends messages) slows or stops altogether. The result is loss of function and the multiple symptoms experienced by people with demyelinating diseases. Without myelin, axons degenerate and die.
Depending on which nerves are affected, symptoms of demyelination may include loss of sensation, movement, intellectual function, balance problems, incontinence and loss of vision.
Some demyelinating diseases are inherited, others are caused by autoimmune reactions, infectious agents or unknown factors. Organophosphates, a class of chemicals which are the active ingredients in commercial insecticides such as sheep dip, weed-killers and flea treatment preparations for pets, etc., may also demyelinate nerves.
Demyelinating diseases of the central nervous system (CNS) include:
- Multiple Sclerosis (MS)
- Leukodystrophies
- Vitamin B12 Deficiency
- Acute Disseminated Encephalomyelitis
- Tranverse Myelitis
- Central Pontine Myelinolysis
- Tabes Dorsalis
- Devic’s Disease
- Progressive Multifocal Leukoencephalopathy
- Optic Neuritis
Demyelinating diseases of the peripheral nervous system include:
- Guillain-Barre Syndrome
- Anti-MAG Peripheral Neuropathy
- Charcot-Marie-Tooth Disease
- Copper Deficiency
Multiple studies are under way to repair or regenerate myelin in patients with demyelinating diseases, particularly MS. What is learned about myelin repair for MS may also provide insights into developing treatments for other neurological diseases and conditions such as Alzheimer’s, Parkinson’s, ALS, and spinal cord injuries. These treatments could lead to an improved quality of life for millions living with chronic, debilitating and eventually life-threatening diseases.