Epidemiology of multiple sclerosis

Multiple sclerosis is a complex trait that appears to be determined by both genetic and environmental factors. It is a neurological disorder with a highly characteristics disease distribution.

It exhibits a changing incidence over time in an uneven geographic distribution. Multiple sclerosis affects about 350,000 people in the United States and about 1.1 million people throughout the world.

The most important risk factor for multiple sclerosis is being a woman, which is reflected in the increasing incidence of multiple sclerosis in women. There is a complex interaction between gender and inheritance of multiple sclerosis, leading to a parent-of-origin effect highly suspicious for an epigenetic of multiple sclerosis.

Multiple sclerosis is 20 to 40 times more common in first degree relatives and drops off rapidly with more distant relationships. The incidence of multiple sclerosis is not increased in adopted relatives of multiple sclerosis patients.

High risk areas of multiple sclerosis include northern and central Europe, Italy, northern United States, Canada, southeastern Australia, New Zealand, and parts of the former Soviet Union, with rates greater than30 per 100,000 populations.
Epidemiology of multiple sclerosis

Multiple sclerosis

Multiple sclerosis is an immune disorder affecting adults of all ages and the most common inflammatory disease of the central nervous system. It is unpredictable and can result either in only minor –physical impairment or in severe disability.

Multiple sclerosis is considered a demyelinating disease in that the myelin in the central nervous system is disseminated. Myelin, the insulator of nerves is attacked by the immune system because of improper recognition of self as intruder. The demyelinization may slow the nerve impulses, causing loss of muscle power or distortion of sensation, or may block them altogether.

Multiple sclerosis is caused by an interplay genetic and environmental factors. This incidence in the general population is about one in 800 but it is one in 50 for children of an affected parent, one in 20 for siblings of an affected person, and one in three for identical twins of multiple sclerosis patients.

Women are disproportionately affected outnumbering men nearly 2 to 1. The disease typically begins from age 20 to 50. However, individuals with disease onset after age 50 are not rare.

Early symptoms of multiple sclerosis may be mild and vague, and hence may be dismissed by affected individuals or their families. Such symptoms include blurred vision, tingling or numbness in the trunk or extremities, vertigo, intention tremor and clumsiness.
Multiple sclerosis