Monday, September 11, 2006

What is Multiple Sclerosis?

Multiple Sclerosis is one of the most commonly diagnosed diseases of the central nervous system (the brain and spinal cord). Nerve fibers are surrounded by a protective sheath of myelin, a fatty substance – see? Fat indeed has positive attributes. In MS the myelin sheath is attacked by cells from the body’s own immune system. For reasons not yet known, these immune system cells leave the blood stream that feeds the central nervous system and travel into brain and spinal cord tissue. We call this “breaking the blood/brain barrier.” Not as glamorous as breaking the sound barrier but far more destructive when things go awry. This invasion produces inflammation, myelin destruction, and actual destruction of nerve axons. Axon damage can occur at an early stage of the disease, resulting in permanent damage since axons, unlike myelin, do not regenerate. At the sites of myelin and axon destruction, hardened scar tissues form. These are called plaques, lesions, or sclerosis – hence the name multiple sclerosis.

Imagine a breakdown of the insulation surrounding electrical wiring. Electrical current can be severed, resulting in its loss as it travels from its place of origin to its intended destination. In MS, as myelin and nerve cells are damaged or destroyed, the breaks or the lesions prevent the signals traveling the central nervous system from reaching their various destinations throughout the body. This signal loss results in a myriad of symptoms, ranging from pain and paralysis to cognitive impairment. Much more on symptoms later.