Former heavyweight boxing champion Muhammad Ali is also a sufferer

At the official launch of the Foundation in Washington DC's Capitol Hill, he admitted he initially viewed his illness as "my own personal enemy", but went public about it in 1998 after listening to other sufferers.

"It was just a slow evolution," he said. "Once I made public my situation, the overwhelming and unbelievable support was so moving and so inspiring to me."

Parkinson's Disease is a progressive neurological disorder which causes the stiffening of muscles and the shakes.

Other celebrities who have been afflicted by it include former world heavyweight boxing champion Muhammad Ali.

Funding

Fox made his first appearance on Capitol Hill last September to call for an extra $75m (�46m) in funding from the US Senate.

Several politicians have lent him their support, including Senate majority leader Trent Lott, who predicted there would be more cash made available.

Fox, meanwhile, hinted that he would make guest appearances on Spin City and said he plans to act, produce and direct again one day.

For now, though, he is using his fame to try and help others.

"The feeling of being able to serve, to offer up my story, as much as it is uncomfortable, it's a tremendous privilege," he said.