TORONTO - Although Michael J. Fox turned 50 this year, the boyish actor who charmed audiences in "Family Ties" and "Back to the Future" says his battle to find a cure for Parkinson's disease keeps him young and too busy to feel ill.

The Emmy Award-winning star told roughly 2,000 people gathered at a North American health conference Tuesday that his condition appears to have plateaued and that once-severe episodes of Dyskinesia -- a movement disorder that causes him involuntary tremors and sudden jerks -- have diminished.

Accepting the disease and surrounding himself with like-minded supporters have helped him thrive beyond many people's expectations, he said, noting that anyone in a similar situation can do the same.

"You have to empower yourself, acknowledge what the situation is, acknowledge what your goal is and just move toward it," Fox said at the HealthAchieve conference, an annual three-day gathering that draws more than 7,000 delegates from Canada and around the world.

"And that quest keeps me young, it keeps me involved. I don't have time to get worse."

In addition to promoting his work with the Michael J. Fox Foundation for Parkinson's Research, the actor-turned-activist said he still enjoys performing, and drew applause from the crowd when he mentioned recent appearances on "The Good Wife" and "Curb Your Enthusiasm."

Fox said he's open to adding more TV roles to his resume and said he wouldn't even rule out a return to the big screen, if the film project was right.

"I'm open for whatever's out there," he said to an enthusiastic crowd that greeted him with a standing ovation and offered another at the end of his 30-minute speech and about 20 minutes of questions.

"A movie would be a big undertaking but who knows, we'll see what happens."

Peppering his keynote address with humour-filled tales from his childhood in Canada, his ascension in Hollywood and his recent role as one of the world's foremost advocates for Parkinson's research, Fox stressed his positive outlook as the key to carrying him through life's toughest moments.

Fox was just 29 when he was diagnosed with early-onset Parkinson's, a degenerative neurological disorder characterized by progressive loss of muscle control.

He had noticed an uncontrollable tremor in his pinkie finger while shooting the 1991 film, "Doc Hollywood," but refused to believe he was ill -- after being told he had Parkinson's he sought a second, then a third and a fourth opinion. He says it took him years to accept what doctors were telling him.

"It was kind of like being stuck in the middle of the street with your feet in concrete, unable to move and you know a bus is coming," said Fox, who shot to fame by portraying cocky young Republican Alex P. Keaton on "Family Ties."

"You don't know when and you don't know how fast it's travelling, you feel its vibrations but you don't know when it's going to hit."

For years, he kept his condition secret, sharing it only with his family. He admits he feared how fans would react, and therefore waited until the third season of his sitcom "Spin City" to publicly acknowledge he was ill.

"Timing in a joke depends on the audience being with me and I didn't think they'd think I was funny if they knew I was sick," says Fox, who moved side-to-side as he read notes from a podium, his speech occasionally slurred and his head often cocked to one side.

But Fox says he was astonished when other Parkinson's sufferers embraced him as an inspiration, and dedicated his life to raising awareness and finding a cure.

He created the Michael J. Fox foundation in 2000 and says it has handed out $250 million in research funds. Roughly $10 million has gone to Canadian projects, he says.

During a question-and-answer period after the speech, one health-care worker asked how to encourage patients to adopt Fox's positive outlook.

Fox stressed that each patient has their own journey to follow, and cautioned loved ones against imposing their perceptions about how patients should cope.

"Even with caregivers and people that love and care for them, they project stuff onto them and the patient ends up feeling that way," he says, recounting a story about a woman who complained her husband was in denial about his Parkinson's because he spent his time golfing and skiing.

"Acceptance doesn't mean resignation, it just means acknowledgment of the truth," he says.

"That was important for me, to realize that I was still me. I was me, plus this challenge. And it didn't have to eat a big part of me."

Fox said he sees his life as one of possibilities.

"It's the refutation of the idea that your fate is locked and the outcome of your life is certain," he says.

"You may feel you've been cast in a tragic role but it's really all about how you play it."