After it was revealed this week that Jack Osbourne has been diagnosed with multiple sclerosis (MS), a neurological condition that damages the nerves and affects the transfer of messages around the body, many marvelled to Pam Macfarlane, of the MS Trust, at how young he was.

"Actually, he's probably about the average age of someone to be diagnosed but there's this general impression that it's something old people have," she says.

This is just one of the many misconceptions surrounding the condition and to have someone with as high a profile as Osbourne can be valuable to those with MS and those working for its charities.

"I'm conscious that I don't want to come across like we're jumping up and down that a famous person has MS," Ian Fannon, of the MS Society in the UK, says.


"It's a terrible thing and it's obviously going to be a difficult time for him and his family but there can be huge benefits when celebrities speak about a diagnosis like MS because awareness of the condition is very, very poor. For the public to be interested in what having MS means and what the symptoms might be is a good thing."

It is not uncommon for those diagnosed with MS to keep it a secret, concerned that if their condition were made public it could harm their careers. Fannon points out that most people have a form called relapsing/remitting MS. If they are in a remission period, they can seem unaffected.

"We did a recent survey that showed that over three-quarters of people with MS can think of at least one occasion when somebody has questioned the fact that they had MS because they looked well," he says.

"A lot of people don't understand the symptoms. Others said they could recall at least one occasion when people had mistaken their symptoms for drunkenness. When someone in the public eye can speak out, it can be really beneficial in terms of breaking through that poor understanding."

We've seen before the positive effect that can occur when a celebrity opens up about their health issues, the most recent of which was the reality-television star Jade Goody's cervical cancer.

After Goody, who died in 2009, was diagnosed, screening tests rose by up to 50 per cent, something that was dubbed the "Jade Goody effect". The novelist Terry Pratchett's openness about his Alzheimer's has seen a surge in awareness about the disease, particularly with the programmes he made about living with the disease that were watched by millions. Michael J Fox has been applauded similarly for bringing his Parkinson's to light and setting up his Foundation, which is dedicated to ensuring the development of a cure for the disease.

Like Parkinson's, there is no cure for MS.

"I feel that greater awareness and greater visibility will have an impact on research funding," says Cathy John, a 32-year-old living with MS, "because without the willingness of people to give and lobby for change, the money won't follow. No money means no research and no progress in treatment. I'm sure there are lots of other relatively young people with MS out there but who are not being vocal about having it. I'm appreciative that someone has done that."