Robin Williams Parkinson's Disease: Michael J. Fox Tweets Of Diagnosis

Michael J. Fox took to Twitter on Thursday, where he commented on Robin Williams' Parkinson's disease diagnosis.

Fox was "stunned" when Susan Schneider, Williams' widow, confirmed her husband had been dealing with the early stages of Parkinson's disease, a disorder that attacks the central nervous system.

Fox tweeted, "Stunned to learn Robin had PD. Pretty sure his support for our Fdn predated his diagnosis. A true friend; I wish him peace."

Fox has been associated with Parkinson's disease since he went public with his battle in 1998. Williams was a big supporter of the Michael J. Fox Foundation for Parkinson's Research and often performed at the foundation's annual gala, A Funny Thing Happened On the Way to Cure Parkinson's.

Williams also teamed up with friend and boxing legend, Muhammad Ali, who suffers from the degenerative disease, in 2006, performing at the boxer's Celebrity Fight Night XII benefit.

Over the past 20 years, Ali's annual benefit has raised over $95 million, most of which has been donated to the Muhammad Ali Parkinson Center at Barrow Neurological Institute.

Robin Williams' Wife Refuses to Enter Home

The news of William's early battle with Parkinson's came yesterday in the form of Schneider's public statement.

"Robin's sobriety was intact and he was brave as he struggled with his own battles of depression, anxiety as well as early stages of Parkinson's disease, which he was not yet ready to share publicly," Schneider said. "It is our hope in the wake of Robin's tragic passing, that others will find the strength to seek the care and support they need to treat whatever battles they are facing so they may feel less afraid."

If you or someone you know needs help, please call the National Suicide Prevention Lifeline at 1-800-273-8255.