"We don't know how long I've had it for, but I've been misdiagnosed for 10 years," Williams, 43, said at a Manhattan news conference. "There have been some mornings when I thought it would be better if I stayed in bed."
But he vowed: "This disease is not going to stop me."
The host of the nationally syndicated Montel Williams Show, which has been on the air for eight seasons, said he will continue to work as long as he is physically able.
Williams said he recently informed his immediate family of his condition and told his staff on Monday, shortly before the news conference.
He made the announcement in the company of his wife, Grace, Frank Kelly, co-president of domestic television for Paramount, and his personal physician, Dr. Michael Olek of Massachusetts General Hospital, Brigham Women's Hospital and Harvard MS Center.
Olek said they have been discussing several recently approved drug therapies. Williams has been seen by neurology specialists at Harvard and the Karolinska-Nobel Institute in Stockholm, Sweden.
Throughout his illness, Williams said he had been working 18-hour days to direct his first feature film, a drama titled Little Pieces. He maintained his commitment to his career as a talk show host.
"Even if this gets worse in five or 10 years from now, I will still force myself out of my bed," said Williams.
"The hardest part Montel has with this disease is not having control. He's had control of everything in his life, from being a naval officer to his talk show. But not his family," joked his wife, Grace, in a moment that briefly broke her seriousness.
"She's got control there," agreed Williams, kissing his wife. They have four children: Ashley, Maressa, Montel II, and Wyntergrace.
Williams also announced the creation of a multiple sclerosis research fund. "I hope that by me coming forward today ... that just the use of my name will maybe increase people's donations so that in the next five years we can cure this," he said.
Kelly, of Paramount, expressed his support. "Montel has been a partner and friend at Paramount and he'll attack this just like everything else," he said.
Donations can be sent to: Montel Williams MS Research, The Foundation for Neurological Diseases, 10 State St., Newburyport, Mass. 01950.
For more information on multiple sclerosis, visit the National Multiple Sclerosis Society web site.
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