You may have heard about the disease normally known as Multiple Sclerosis - but what is it and what causes it?

Multiple Sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system. First described by Jean-Martin Charcot in 1868, MS(formerly known as disseminated sclerosis) is more common in women than in men and typically affects - depending on country and actual population - between 2 and 150 people per 100,000. The disease usually has its onset in early adulthood.

The disease affects the 'white matter' of the brain. Cells in white matter - present in the brain and spinal cord - carry signals for processing to 'grey matter' areas and also between these areas and the rest of the body. MS affects the neurons in the white matter - specifically destroying the cells known as 'oligodendrocytes' that are cells responsible for creating the 'myelin sheath' - a fatty layer that assists the neurons in the carrying of electrical signals.