Parkinson’s disease can quietly occupy a person’s body for years before they notice it. But a new study shows it is possible to detect the first flicker of the disease with a smartwatch. 

Wearable devices can pick up a telltale sign of Parkinson’s disease – slowing movement – up to seven years before a person is diagnosed, the British study found. 

Tracking more than 100,000 people using accelerometer devices (like smartwatches) found that this method of detecting Parkinson’s outperformed all other predictors, such as genetics, lifestyle, or blood analysis. 

And while it could not replace clinical diagnosis, researchers in New Zealand and overseas said it was a potentially important, low-cost screening tool for identifying people at risk of developing the disease. 

“The key thing here is that [brain] cells will be dying off over many, many years,” said Professor Louise Parr-Brownlie, who specialises in Parkinson’s disease at the University of Otago. 

“By the time someone’s Parkinsonian, they’ve had at least 50 per cent of their cells die off, it’s probably closer to 70 per cent. 

“So if we get that window where we get the hint that something is changing then it gives us an opportunity to halt – if we are able to – or even slow the progression. 

“That means that people stay independent for longer, they’ll be able to live at home for longer, quality of life will be maintained, they’ll be able to stay in the workforce, for some people.” 

Otago University's Dr Louise Parr-Brownlie says by the time someone’s Parkinsonian, about 50-70 per cent of their brain cells have died off. Photo / Supplied 

In New Zealand, around 12,000 people have been diagnosed with Parkinson’s. It has a long latent phase and patients are not usually diagnosed until symptoms – like involuntary shaking and slowed movement – become obvious. 

There is no cure for the disease and the damage to the brain cannot yet be reversed. That was the Holy Grail, the “magic thing that we’re all trying to find”, Parr-Brownlie said. 

Treatment instead focuses on controlling symptoms and improving quality of life. 

Ruth Monk, a postdoctoral research fellow at the University of Auckland’s Centre for Brain Research, said there was still “enormous” scientific and clinical interest in identifying patients in the early phase of Parkinson’s. 

“A step towards being able to identify people in the very early stages of Parkinson’s is a step towards finding a way to stop the progression of Parkinson’s in its tracks, and in an ideal scenario, to reverse any progression that had already been made,” she said. 

Monk’s work focuses on biological signs of Parkinson’s, in particular loss of smell. 

Around 90 per cent of people with Parkinson’s report reduced sense of smell, and her research proposes that the progression of the disease could be stopped in its tracks by preventing the spread of damage from the nose to the brain. 

Andrew Bell, from Warkworth, was diagnosed with Parkinson’s in 2019, aged 56. 

He was alert to possible symptoms because his father also had the condition. The first warning sign came when he could not double-click his computer mouse and needed two hands to move it. 

A neurologist confirmed he had a cluster of symptoms associated with Parkinson’s, and when his body responded to treatment, his doctor said it was likely that he was Parkinsonian. 

“It was like being hit by a bucket of cold water,” he said. “The words are just bouncing off your head as he talks at you.” 

Bell is now on a regime of medication, which supplements the dopamine in his brain, and exercise, which can help with mobility and cognitive issues. He credits these measures with slowing his deterioration. 

Bell, who is head of Parkinson’s NZ, said the smartwatch study appeared to show some promise. 

“I don’t think we’ll get to the point of smartwatches diagnosing Parkinson’s. But it could be a canary in the mine situation. 

“If I found out two years earlier, my ability to ‘push’ the Parkinson’s would have started earlier. The sooner you [know] … the more likely you are to extend the functional years that you have.” 

Isaac Davison is an Auckland-based reporter who covers health issues. He joined the Herald in 2008 and has previously covered the environment, politics, and social issues.