What is MS and what are the causes?

MS is the most common disabling disease of the central nervous system (the brain and spinal cord) affecting young adults. In MS, damage or scarring occurs to the myelin sheath – a layer of fatty protein that protects the nerves in the same way that insulating material protects an electric wire. This damage (called demyelination) disrupts the way in which messages, or nerve impulses, are carried to and from the brain and so it can interfere with a range of the body’s functions. The term 'multiple sclerosis' comes from 'sclerosis', which means scarring and 'multiple', which relates to the sites of the scarring, which can occur in different places throughout the brain and spinal cord. The symptoms experienced will depend on the position and extent of the scarring within the central nervous system and on how much damage has occurred. In the earlier stages of MS, the central nervous system can often compensate for areas of damage by repairing myelin or by re-routing messages around the problem area. This explains why episodes of symptoms (relapses) can be followed by weeks, months or even years when symptoms improve or disappear (remission). However, if the area of damage becomes too large, communication with that specific part of the central nervous system may become permanently blocked.

Almost 150 years after the condition was first recognised, the cause of MS remains a mystery. The theory that is widely held is that MS is an autoimmune disease. An autoimmune disease is one in which the immune system, which should only target invading germs, turns on the body’s own tissues. In the case of MS, the immune system attacks the nerve coverings in the central nervous system. The reason for this reaction is unknown but it is thought that the genetic make up of some people means that read more