Light used to slow Parkinson’s
The power of light is emerging as a promising way of slowing devastating brain conditions such as Parkinson’s disease.
Clinical trials are under way across the country testing whether applying “laser helmets” to the head of patients can improve symptoms and halt disease progression.
But a new study from the University of Sydney has found that applying low-level light to other parts of an animal’s body — particularly the abdomen — can be even more effective at protecting brain cells.
Low level laser therapy, or photobiomodulation, has been used for the past 50 years — typically to treat pain or inflammation — but evidence is emerging of its potential benefit for the brain.
The Sydney team first showed in 2010 that by shining this near infra-red light on to the heads of mice with Parkinson’s disease, it could protect against the loss of brain cells.
“Following that, we’ve done heaps of studies that have used different wavelengths of light, altering when we give the light — either before, during or after the injury — and we consistently show we can protect the brain,” lead researcher Daniel Johnstone said.
“The problem you face moving into humans is that even at these longer wavelengths we use, you lose about two-thirds of your intensity for every millimetre of tissue you pass through.
“We have thick skulls.” Dr Johnstone said as his team was driven to find an alternative delivery, they were spurred on by incidental findings in studies by other laboratories around the world that had used light to treat wounds and chemotherapyrelated mouth ulcers, that could repair tissue that was not directly irradiated.
After successful studies in mice using this remote light delivery, their most recent proof of concept study in three Parkinson’s disease monkeys, found that delivering light to the head gave no neuroprotection.
Delivering it to the lower legs delayed the onset of symptoms, while shining the light on its abdomen prevented the animals from showing symptoms of the disease.
The results were presented at the Australasian Neuroscience Society’s annual scientific meeting this week.
Dr Johnstone said while their findings had informed human clinical trials using this remote delivery technique in Adelaide, Brisbane and Sydney, they would now return to mice studies aiming to confirm the findings.
US photobiomodulation expert Michael Hamblin, who conducted in a national tour promoting laser therapy research in brain disease to an audience of Australian health professionals, said while the field had suffered a “bad name, a sense of quackery” because of false claims, scientific evidence was changing that.