It is a disease of the central nervous system.The symptoms of this disease is myelin (fatty insulating sheathes protecting nerve fibres) becomes damaged and scarred. It affects a person's motor, sensory and even cognitive functions. The causes of Multiple sclerosis are genetic and environmental factors. The impact and symptoms of Multiple sclerosis depends on a person's ability to participate in everyday activities different from person to person.
There were 123 studies that met the inclusion criteria. The study estimates were highly heterogeneous, even within regions or countries. Quality was generally higher in the more recent studies, which also tended to use current diagnostic criteria. Prevalence and incidence estimates tended to be higher in the more recent studies and were higher in the Nordic countries and in northern regions of the British Isles.