definition of demyelination
By Sally Robertson, BSc. The term demyelination refers to loss of the myelin sheath that surrounds and protects axons in the central nervous system. Demyelination occurs as the result of diseases that damage the myelin sheath or the cells that form it. Diseases that are characterized by this loss of myelin are referred to as demyelinating diseases. The myelin sheath covers and insulates axons, aiding the conduction of electrical signals between nerves.