Michael J Fox 'stunned' to learn friend Robin Williams had Parkinson's disease

The Back to the Future actor, who himself has the illness, tweeted his shock at Williams' diagnosis

Michael J Fox has spoken of his shock at learning that his friend, the late comedian Robin Williams, had been suffering from the early stages of Parkinson’s Disease.

Williams’ wife, Susan Schneider, revealed the diagnosis in a statement yesterday (14 August).

“Robin's sobriety was intact and he was brave as he struggled with depression and anxiety as well as early stages of Parkinson's disease which he was not yet ready to share publicly,” she said.

The Back to the Future actor told his followers on Twitter he was “stunned” to learn the news.

Fox, who was diagnosed with the incurable condition in 1991, went on to say that he was “pretty sure” that Williams’ support and fundraising for his Michael J Fox Foundation for Parkinson’s Research far predated the comedian’s own prognosis.

Sufferers of Parkinson’s disease often experience tremors, slowed movement and stiffened, inflexible muscles as the brain becomes progressively damaged over the years.

Those with Parkinson’s may also experience other physical and psychological symptoms, including depression, insomnia, loss of a sense of smell and loss of memory.

Williams, 63, was found dead on Monday after hanging himself at his home in Tiburon, California.

His daughter, Zelda Williams, talked of the last day they spent together on his recent birthday, when she and her brothers shared “gifts and laughter”.

Robin Williams and his wife Susan Schneider at the premiere of "Old Dogs" in Los Angeles on 9 November 2009

“He was always warm, even in his darkest moments,” the 25-year-old said.

“While I'll never, ever understand how he could be loved so deeply and not find it in his heart to stay, there's minor comfort in knowing our grief and loss, in some small way, is shared with millions.”

Barack Obama, Prince Charles, Steven Spielberg and countless actors who worked with Williams in his decades-long career were among those who shared their memories of the comedian in an unprecedented outpouring of tributes.