However, it does appear to be more common in white people living in Northern Europe, America and Australia, than in Africa and Asia. The disease is also more common in women than men, about three women have the disease for every two men. RRMS patients suffer from relapses or exacerbations, which are unpredictable occurrences of new symptoms or worsening of old symptoms punctuated by remissions. In MS, the immune system attacks myelin. This is a fat-like substance that surrounds all the nerve cells of the central nervous system.
Myelin insulates nerve cells and speeds up conduction of the small electric currents they produce.
These depend on the areas in the brain that are affected by loss of nerve function. Nevertheless, most patients, particularly early on in the disease, have only a few symptoms. The first two types of treatment reduce the symptoms but have no effect on the natural course of the disease, so that it continues to progress. The corticosteroids are potent anti-inflammatory agents, so can be used to reduce the inflammation in the central nervous system during a relapse, and to speed up recovery from that relapse. High doses of methylprednisolone given by injection into a vein seem to be most effective in treating relapses.