The autoimmune system of the body maybe triggered by a viral infection which then causes multiple sclerosis
The immune system, which attacks foreign invaders like bacteria and viruses, mistakenly directs its defense cells like the white blood cells and antibodies against the body itself. In the case of Multiple Sclerosis (MS) the protein present in myelin or the insulating material of the nerves is attacked by the antibodies.
This leads to damage of the covering sheath – a process called ‘demyelination’ followed by damage to the nerve itself. When the nerve is damaged, that part of the body served by that nerve is disconnected from the rest of the brain and its functioning is affected. When the area heals, it does so with a scar-giving rise to ‘sclerosis’
1. Genetic - Twins of siblings suffering from MS, children of parents having MS are more likely to get the disease compared to children whose parents who do not suffer from MS.
Though MS is not a hereditary disease the tendency to develop MS is inherited.
2. Viral Infection - A viral infection can produce a protein that resembles myelin. The immune system does not distinguish between the protein of viral origin and the myelin of the nerve fibers and attacks the myelin. In some patients, MS has been known to occur after an attack by a virus called Epstein-Barr virus.
1. Heredity - People of North European and Caucasian origin seem to be more prone to getting the disease. It is commonly seen in Northern Europe, and North America, but is rare in the Australian Aborigines, the Inuit of Canada, and Maori tribes of New Zealand and in sub-Saharan Africa. The tendency to develop MS is inherited, but the disease may manifest only when environmental triggers are present.
2. Environmental Factors - Infection during a crucial period may lead to conditions conducive to developing MS even as late as a decade later. Interestingly people from tropics who move to temperate climates after the age of 15 years do not show an increased incidence of MS, but those who migrate before the age of 15 have the same risks as a person living in the temperate regions. Stressful life events increased the risk of developing new lesions by 1.6 times.
Lack of Vitamin D has also been suspected as a cause for the disease as it is rare in the tropics.
Triggers of an attack include viral flu or following pregnancy.
- Comparison between multiple sclerosis in India and the United States - A case-control study. Bansil S, Singhal BS, Ahuja G K et al. NEUROLOGY 1996; 46: 385-387
- Neurology India-vol 47, issue 1 pg12-7, 1999Syal p, Prabhakar S et al