Trevor Bayne, the youngest winner in Daytona 500 history, <a href="http://abcnews.go.com/Health/nascar-driver-trevor-bayne-ms-diagnosis-doesnt-change/story?id=20871904"target="external">announced he has multiple sclerosis</a>, Nov. 12, 2013. Bayne stands in the garage area during practice for the NASCAR Nationwide Series ServiceMaster 200 on Nov. 8, 2013, in Avondale, Ariz.

Actor Richard Pryor started using a wheelchair in 1990, four years after he was diagnosed with multiple sclerosis. He died from a heart attack in 2005.

Country music star Clay Walker was diagnosed with multiple sclerosis in 1996. He was just 26 years old.

Actress Teri Garr became an ambassador for the National Multiple Sclerosis Society after revealing her diagnosis in 2002.

Jack Osbourne was diagnosed with multiple sclerosis when he was 26, just two weeks after the birth of his daughter, Pearl Clementine. Most patients are diagnosed with the disease around age 37.

Ann Romney said her multiple sclerosis symptoms worsened during the 2012 presidential campaign. She was diagnosed with the disease in 1998 at age 48.

In her book, "The White Album," author Joan Didion said she went blind for six weeks during a bout of multiple sclerosis in 1986.

Former talk show host Montel Williams was diagnosed with multiple sclerosis in 1999. Soon after, he launched the Montel Williams MS Foundation to further the scientific study of MS.

Michaele Salahi, the reality TV star who crashed a 2009 White House party with then husband Tareq Salahi, revealed she has multiple sclerosis in the 2010 book "Cirque de Salahi."

Beloved Disney star Annette Funicello announced she was battling multiple sclerosis in 1992. She died Monday, April 8, 2013, at age 70 from complications of the disease.

Alan Osmond – brother to Donny and Marie – is battling multiple sclerosis alongside his son, David. David Osmond was diagnosed with the disease at age 26.