Here is an excerpt from the article on MS. The entire supplement is available at the bottom of the page.

Multiple sclerosis (MS) is a disease  of the central nervous system. While the cause isn’t yet known, it’s believed to be an autoimmune disease, which means that in MS the immune system attacks healthy tissue in the body—in this case, the myelin that surrounds and protects the nerves. The damaged myelin forms the scar tissue (sclerosis) that gives the disease its name. When any part of the myelin sheath or nerve fiber is damaged or destroyed, nerve impulses traveling to and from the brain and spinal cord are distorted or interrupted, producing the variety of symptoms that can occur. Most commonly, these include fatigue, loss of mobility, bladder and bowel dysfunction, vision problems, dizziness and vertigo, sexual dysfunction, numbness or pain,  cognitive changes and depression. Over the course of the disease, some symptoms will come and go, while others may  be more lasting. 

One of MS’s peculiarities is that its symptoms, severity and prognosis are different  in everybody. People with MS typically experience one of four disease courses—relapsing-remitting, primary-progressive, secondary-progressive and progressiverelapsing—each of which might be mild,moderate or severe. The majority of people with MS do remain ambulatory.It is estimated that there are over two million people worldwide who have been diagnosed with MS. While most people are diagnosed between the ages of 20 and 50, MS can appear in young children and  teens as well as much older adults. Moreover, two to four times as many women as  men are diagnosed with MS.

Read more in pdf file for a Wall Street Journal supplement