Thousands of New Zealanders living with Parkinson's are being given hope with a new drug-delivery device that aims to restore movement.
For the last 11 years, University of Otago Professor Dr John Reynolds has been working on a treatment that would reverse the crippling impacts of Parkinson's.
Now, a device that would be implanted underneath a patient's scalp, injecting medicine more precisely, brings promise.
Almost $5 million has been granted by Ministry of Business, Innovation, and Employment (MBIE) over the next four years to make the device "human-ready".
Reynolds - who spoke at Queenstown's medical research conference this week - explained Parkinson's occurred when a person's dopamine brain cells, which controlled movement, started to die.
But it's not until around 70 per cent of the cells were lost that symptoms occurred.
People with Parkinson's were normally given synthetic L-dopa, the amino acid used to make dopamine.
The drug floods the brain, ''supercharging'' the remaining cells and eliminating most of the physical symptoms of Parkinson's.
"But there are complications," Reynolds said.
"Eventually L-dopa becomes ineffective because the cells continue to die off. And the medication has side-effects. After being taken for a few years it can trigger its own involuntary body movements, called dyskinesia."
The reason for this came down to the timing of nerve impulses arriving at brain cells - a critical part of strengthening new connections while our new memories were formed.
Reynolds discovered the pulse of dopamine into the brain that accompanies the arrival of a reward had its own critical timing requirement, this time in the order of seconds.
"Instead of filling up dopamine like a bucket, we thought why wouldn't we try to find a way to mimic the natural dopamine signal."
With a minor surgery, a patient could have the device implanted in the brain and the drug could be injected into the brain in this way.
"It's been 11 years of work so far and we still have a lot to do but we have a lot of proof that it should work," Reynolds said.
Prototypes of the device have been created and were being tested on sheep, which had shown promising results.
Reynolds said he met a man who had Parkinson's who couldn't even sit on a chair properly and it was awful.
"I said: 'Look, if we were going to do a bit of surgery and put something under your scalp and inject you every couple of days would you want it?' He turned to me and said: 'Sign me up right away'."
"If this works, it will be major and could be used all over the world."
The project is part of an MBIE initiative to develop a medical device business in New Zealand.
What is Parkinson's disease?
• A progressive neurodegenerative condition.
• Caused by insufficient quantities of dopamine - a chemical in the brain which enables well co-ordinated movement.
• One in 500 New Zealanders suffers from it.
• Average age for diagnosis is 59.
• The main motor symptoms are:
-Stiffness and rigidity
-Slowness of movement
-Other symptoms can include changes in mood and anxiety, poor balance and altered speech