Multiple Sclerosis (MS) Definition

Multiple Sclerosis (abbreviated MS and also called Disseminated Sclerosis or Encephalomyelitis Disseminata) is an autoimmune disease characterised by a malfunction of the immune system which attacks the central nervous system causing damage to the myelin sheath of neurons in a process called demyelination.

Myelin is a material that covers each fibre in the central nervous system and plays a crucial role in the transmission of messages from the brain to the rest of the body as it increases the speed at which those impulses propagate in the nervous fibres. By degrading the layer of myelin that surrounds the nerves the disease interferes with communication between the brain and other parts of the body, causing an irreversible deterioration of the nervous system. When myelin degrades transmission of signals along the system can be impaired and the nerve function affected or lost completely.

This disruption in the transmission of signals between the brain and the body is completely unpredictable and MS is a chronic progressive neurodegenerative condition, which can range from relatively benign to highly disabling.

The name Multiple Sclerosis refers to scars or lesions that the disease causes to the white matter of the brain and the spinal cord, which is mainly composed of myelin. MS lesions are a result of the demyelination process.