Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 103 What is MS? MS affects the central nervous system, which is comprised of the brain and spinal cord. In the CNS, nerve fibers (called axons) are protected by a fatty layer of insulation called myelin. Myelin allows nerve signals to travel properly. In MS, overactive immune cells cause inflammation, which damages the myelin. This results in a loss of myelin – called demyelination – and some degree of axonal damage. Wherever the myelin is destroyed, a damaged area of white matter known as a lesion (or plaque) will occur. Over time, hardened scar tissue develops at the lesion site. This hardened scar tissue, or sclerosis, may develop at multiple sites throughout the CNS, hence the name multiple sclerosis. This scarring disrupts the transmission of nerve signals that communicate a desired action from the brain, through the spinal cord, to various parts of the body. THEUNPREDICTABLEDISEASE Imagine this: you disconnect your cell phone from its charger as you get ready for a busy day. But even though it has been connected all night, you notice the battery is only partially charged. You look at the cord and notice a spot where the insulation has been stripped away and the wires inside are exposed. Because the path by which the current travels is damaged, not all of the electricity sent from the outlet reached its target, your phone. This analogy is helpful in understanding MS. Signals from the brain travel along nerves that are insulated with a substance called myelin. This insulation allows the signal to reach its destination without disruption. In MS, the insulation becomes damaged or lost, causing the nerve impulses traveling to and from the brain and spinal cord to be interrupted or distorted, producing the many symptoms associated with MS. Of course,the central nervous system is much more complex than a simple cord, and this damage can occur anywhere within it. For that reason, MS can cause a wide range of different symptoms, ranging from mild to life-altering. Of the more than 50 recognized symptoms, no one can predict which symptoms any one person with MS will experience. Additionally, most people are initially diagnosed with a relapsing form of the disease, in which symptoms can come and go. For these reasons, it is often said that the only thing predictable about MS is its unpredictability. This makes the condition challenging to diagnose and treat, and is especially challenging to live with each day.