Multiple sclerosis affects about 2.5 million people worldwide – and the disabling disease, which affects the body's central nervous system – has always been irreversible.

However, doctors at the Cleveland Clinic are using a special type of stem cell to relieve the symptoms of MS and possibly reverse damage the disease has caused.

Bill White, a veteran of the Navy and former gym owner, said he was devastated when he developed MS five years ago. He is the first patient in North America to take part in the study, which uses his own stem cells to treat his disease.

"I mean, you never think you're going to get a disease," White said.

Dr. Jeffrey Cohen of the Cleveland Clinic said the main goal of the study is to demonstrate that the treatment is safe, but also to find out if the treatment will benefit the patient.

White's bone marrow, which contains mesenchymal stem cells, was collected, then purified and multiplied. After four to six weeks, doctors gave White an infusion of these stem cells, which are thought to decrease the damaging immune activity.

"We've had a number of effective treatments for MS that slow down the disease, but nothing that repairs the damage that has already occurred and many of us think that stem cells is one of the most promising approaches to accomplish that," Cohen said.

Two months after the infusion, White said he has not had any side effects. He said he has better eye movement and muscle movement.

"My whole left side was even worse, I couldn't lift my leg," White said. "It's little things like that and all of a sudden I'm noticing, and I'm excited."

Cohen said it will be approximately two years before they have definite results of White's study, but they'll continue to monitor him to determine the benefits.