Press Release – University of Otago
Research indicates new hope for Parkinson’s disease sufferers
Research at the University of Otago indicates remarkable success with a new approach to treating Parkinson’s disease that holds out new hope for dramatically improved movement and quality of life for sufferers.
Parkinson’s disease causes the progressive degeneration of the dopamine-producing cells in the brain leading tosymptoms that include tremors, stiffness and rigidity, and slowness of movement. The disease cannot be cured and the best treatments so far include drugs and ‘deep brain’ stimulation.
Now however, using ‘optogenetics’ – a method of treatment that stimulates the brain by shining blue light onto the affected area – scientists, working with animal models, are showing much improved ability to recover movements.
Otago School of Medical Sciences neuroscientist, Dr Louise Parr-Brownlie, whose research has just been published in the Journal of Neuroscience, explains that the results indicate better outcomes than treatments commonly used to address symptoms caused by Parkinson’s disease.
‘The results so far achieved offer a new treatment site for deep brain stimulation that may be more effective in addressing symptoms in Parkinson’s disease patients,’ says Dr Parr-Brownlie.
‘If our trials are successful this will represent the first big breakthrough in the treatment of Parkinson’s disease which is a very difficult condition to manage and one that is affecting a growing number of New Zealanders.’
Some 10 thousand people (in New Zealand) have Parkinson’s disease, 80 percent of whom are Baby Boomers in the 60 plus age group. While age is the biggest risk factor, there is a small group of sufferers in the 20 to 50 category.
Although the cause of Parkinson’s disease remains unknown, other risk factors include exposure to pesticides, insecticides, welding fumes and well water. Genetics also plays a relatively small role.
Dr Parr-Brownlie says the more focused optogentics approach activates one part of the brain that controls movement called the motor thalamus. Parkinson’s disease causes a loss of dopamine which impairs the motor thalamus which in turn affects the motor cortex leading to a loss of the ability to initiate muscle movement, or ‘akinesia’.
The optogentics approach seeks to reorganise activity in the parkinsonian brain by recoding the neural messages to restore normal movement.
Currently treatments for Parkinson’s disease often cause serious side-effects. The commonly used drug, levodopa, can cause nausea, uncontrolled movements called ‘dyskinesias’ and even hallucinations, while deep brain stimulation can lead to strokes during surgery and altered mood. These side effects are caused because brain stimulation is usually electrical which excites every single cell in the region.
The optogentic trials, on the other hand are likely to have reduced side effects.
‘This is because the treatment is extremely precise as it manipulates a subset of brain cells within a millisecond of resolution,’ explains Dr Parr-Brownlie. ‘In other words, the neural activity in the parkinsonian brain can be corrected, and when this happens movements are improved.’
Outcomes of the initial trials are very promising showing an ability to improve consciously controlled muscle movements known as ‘reaches’ from 10 in five minutes to over 60.
Ongoing trials, explains Dr Parr-Brownlie, will aim to stimulate the brain for longer periods to improve reaches by up to 200 in five minute periods. ‘Within the next 12 months we hope to be stimulating the brain all day and all night which will hopefully recode the brain to resume normal activity,’ she says.
Dr Parr-Brownlie says she is hopeful for human trials, which she expects will ‘dramatically improve quality of life’ for people with Parkinson’s disease, to begin with the next five years.