Multiple Sclerosis

5 Pages 1304 Words

Multiple Sclerosis is one of the most common diseases of the central nervous system affecting both young and old. MS is a chronic disease of the white matter of the central nervous system. More than 400,000 people in North America are affected. The disease usually starts between the ages of 20 and 40 years with an average age of around 30. MS tends to affect more women than men.
In people with MS, there are three processes going on that normally do not occur in healthy people. First, tiny patches of inflammation occur in the brain and spinal cord. Second, the protective myelin coating around the nerve fibers starts to deteriorate. Third, the nerve fibers themselves, called axons, may actually be damaged or destroyed. These processes are never the same in any two people, and when they occur, how quickly, and to what extent can vary a great deal.
The nervous system is nourished by blood vessels that carry oxygen and nutrients throughout the white matter. In MS, errant T cells, key components of the body’s immune system, somehow leak out of the blood vessels and cause swelling and damage in the surrounding white tissue. For reasons not clearly understood, the cells produce messengers that attack the myelin sheath of nerve fibers. When this "demyelination" happens, the transmission of information through electrical signals that travel along the nerve fibers is inhibited. Once the inflammation has subsided, special cells within the nervous system begin to repair the myelin that was damaged by the inflammation. This cycle of damage and recovery occurs over and over in the white matter, often unnoticed. When and to what extent problems become symptomatic depends on the location, the extent, and the severity of the inflammation. If the inflammation occurs repeatedly in the same place, the repair processes may not be able to "keep up," and permanent damage to the axons may occur. When the inflammation covers a large area, it can often...