Raised in Toronto, he grew up with five brothers and sisters in a family known to some as "the Kennedys of Canada" because of their father, Roy McMurtry, a prominent retired judge and former politician who was the second person ever to serve as both Ontario's Chief Justice and Attorney General.
Surrounded by a vivacious, loving family and a constant swirl of friends drawn to his upbeat nature, McMurtry attended Queens University, one of Canada's best universities, where he excelled at basketball and hockey. After starting a camp for disabled children at 21, he pursued a law degree and went on to become a respected attorney.
"What most people love about Harry is that he's just so darn positive," says his wife, Deborah Bradley, a New York City contractor. "It's so lovely being around somebody with such a bright attitude every day. When you are with Harry, you are always happier. He makes other people feel good about themselves."
Life as McMurtry knew it changed dramatically in 2009, when he was diagnosed with early-onset Parkinson's disease, which affected his movement, ability to walk and eventually his speech.
"People ask me if I ever feel sorry for myself," McMurtry, 54, tells PEOPLE. "I think it's important to have a positive outlook. I have been fortunate to get such great care."
Parkinson's, he says, "isn't our permanent sidekick. We just try to live a normal life. I don't let the disease define me."
Not at all, it seems.
Starting May 7, McMurtry is undertaking one of the biggest challenges of his life when he embarks on a 500-mile walk from New York City to Toronto to raise awareness and money for research for Parkinson's.
Even though he has trouble walking, he is determined to get to Canada. "I want to help other people with Parkinson's more than anything," he says.
Through 500 Miles for Parkinson's, which McMurtry started with fellow Toronto native Sarah Bobas, (whose father has Parkinson's), donors can choose to give to one of three charities of their choice: The Michael J. Fox Foundation for Parkinson's Research; the Morton and Gloria Shulman Movement Disorders Centre and The Edmond J. Safra Program in Parkinson's Disease at Toronto Western Hospital; and the Mount Sinai Beth Israel Movement Disorders Center in New York.
McMurtry, who has been training for the walk for almost a year, will trek to his hometown in Ontario with two other people with Parkinson's – Sue Thompson of Toronto, and Dr. Ross Sugar of Baltimore, Maryland. They will walk up to 15 miles a day for 45 days, staying at hotels along the way.
On Friday, they are hosting a kickoff party in Manhattan, as well as events along the route, which runs from the Bronx, into upstate New York and across the Canadian border.
"It's going to be an adventure," he says. "We are excited to get the word out about Parkinson's and help raise money for research."
A Shocking Diagnosis
In 2002, McMurtry, began noticing rigidity in right arm, which kept locking into place. "I thought it was a shoulder injury," he says.
In 2004, he went to see his longtime college friend Dr. Tom Miller, who specializes in rehabilitation medicine. After running tests on McMurtry, he suspected that his longtime friend had Parkinson's and sent him to a movement disorder specialist, who diagnosed him in early 2005 with the debilitating disease.
McMurtry feels fortunate that he was diagnosed relatively quickly. "Sometimes it takes years for people to get diagnosed," he says. Since no tests are able to pinpoint Parkinson's, "They have to rule out everything else like stroke and other genetic diseases."
Things began looking up for McMurtry in 2008, when his movement disorder specialist suggested he undergo Deep Brain Stimulation surgery, which helps to treat the disease's most debilitating neurological symptoms, such as rigidity, stiffness, tremors and walking problems.
With DBS surgery, doctors implant a battery-operated neurostimulator in a patient's chest, which sends electrical impulses to the parts of the brain that control movement and blocks abnormal signals that cause many of the disease's symptoms, according to the National Parkinson Foundation.
"When my specialist in Toronto first suggested the surgery, I thought he was crazy," says McMurtry. "I was still able to work and play sports and was still quite able, so I wasn’t interested in hearing about brain surgery."
He began to change his mind in 2009, when his condition began to deteriorate rapidly. "I was on a pretty downward spiral," he says. "With Parkinson's, your naturally-occurring dopamine gets depleted so you take more to replenish your natural supply. It's a big factor in Parkinson's, but not the only factor, but it plays a pretty significant role."
Unfortunately, the synthetic form of dopamine has brutal side effects, he says. "It can't get to areas of the brain that need it so you have dyskinesia – uncontrolled movement," says Bradley. "His balance was off and he was having a lot of uncontrolled movement and that was preventing him from doing a lot of things."
In 2010, with his condition worsening, McMurtry says he went back to the doctor "and begged for the surgery," even though he knew it was risky.
"There is a one percent chance of death and a two to three percent chance of infection. But it was a risk I was willing to take because the improvement afterward is pretty great."
He underwent the surgery in 2011, which changed his life for the better.
"The biggest impact was that it was stabilizing, because you now have this device that is working 24/7," he says.
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The medications, he says, "ebb and flow. When they work, you can function and when they don’t, you can't function."
A 500-Mile Walk is BornWhile the surgery helped improve McMurtry's uneven gait, which his children call "Harry's swagger," he grows tired easily as the day wears on and sometimes has trouble speaking. "But I was doing much better than I had been," he says.
His walking improved even more after March 2014, which his doctor adjusted the electrical stimulation in his brain.
Now that he was able to move better, he says he wanted to do something "out-of-the-box" to raise money for the disease.
"Even though I had fairly advanced Parkinson's, I thought, 'What is it about me that differentiated me from other people with the disease?' I was still functioning and living my life to the fullest possible. So I decided to do a 500-mile walk."
McMurtry, Bobas, Bradley and the army of volunteers who are helping them are working so hard because "Harry's quality of life and that of so many others have changed because of fundraising efforts like this," Bradley says.
McMurtry adds: "I want to bring more awareness to this disease to all these communities along the way and concurrently raise donations," he says.
"If it can spur a conversation about Parkinson's, it's good for the Parkinson's population."