Ingenious brain stimulation research offers treatment hope for neurological diseases
A team of University of Melbourne biomedical engineers and their collaborators are seeking to develop a world-first brain stimulation treatment that uses ultrasound – delivered via a device within a blood vessel in the brain – to treat symptoms of neurological (nervous system) diseases such as Parkinson’s disease and epilepsy.
The team has received a National Health and Medical Research Council (NHMRC) Development Grant, announced on Friday 15 December, of over $900,000 over three years to advance their ‘endovascular focused ultrasound’ technology.
The team includes industry partner Synchron, a leading brain-computer interface technology company that was seeded out of the University of Melbourne, and will incorporate advances by the company and University researchers.
The endovascular focused ultrasound technique could significantly improve the quality of life for thousands of people living with neurological diseases, with the technology expected to become available in just over ten years. The procedure would be a safer option for many more people than existing brain stimulation treatments, which require open brain surgery and use electrical stimulation rather than ultrasound.
Annotated illustration of brain tissue and proposed project technology. Picture: Supplied.
Project leader, University of Melbourne Clifford Chair in Neural Engineering Professor David Grayden, said many people with neurological diseases do not benefit sufficiently from drug treatments, which become less effective over time.
“If successful, this project will demonstrate that our technology can safely be inserted into a brain blood vessel to stimulate the brain effectively with focused ultrasound and without open brain surgery,” Professor Grayden said.
The project will advance initial research by Dr Jack Drummond, who, as a PhD student under Co-investigator Professor Anthony Burkitt, came up with the idea of using endovascular focused ultrasound for brain stimulation and has joined the team as a Research Fellow. Over the past five years, he has worked with the Melbourne Centre for Nanofabrication and built an array of microscopic devices that generate sound waves and focus energy on neural tissue. These focused sound waves disrupt the communication between diseased neurons.
“Advances in nanofabrication technology – the same technology used to make computer chips – allow us to make ultrasound transducers that are significantly smaller than those used for medical imaging,” Dr Drummond said.
“We can make transducers that are narrower than the width of a human hair; small enough to fit inside a blood vessel. Arranging these transducers into an array will allow us to focus the ultrasound beam onto a therapeutic target of the brain, whilst minimising stimulation of the tissue between the target and the blood vessel.”
Associate Professor Sam John, Co-investigator and Technology Fellow at the Melbourne Centre for Nanofabrication, said that, at present, electrical stimulation of the brain can be used to treat some of these patients.
“However, it involves implanting electrodes through open brain surgery and may not be sufficiently accurate in stimulating the right brain region,” Associate Professor John said.
“Electrical stimulation is sensitive to the positioning of the electrode, which means a small error in placement can result in reduced effectiveness and unwanted side effects.”
Movement-related symptoms of Parkinson's disease and other neurological conditions are caused by disorganised neural signals in the areas of the brain that control movement. When successful, deep brain stimulation interrupts the irregular signals that cause tremors and other movement symptoms by disrupting the disorganised signals. Similarly, neural stimulation can stop seizures in the brains of people with epilepsy and perhaps even prevent them from occurring.
For the ultrasound stimulation, an array of tiny transducers would be inserted permanently into a blood vessel within the brain, most likely via the jugular vein, similar to how stents are inserted into the heart and brain today.
Research team member Associate Professor David Collins, who is an expert on ultrasonic microsystems, said that the transducers would be connected to a device in the chest, much like a pacemaker device, that would power the device and control the ultrasound stimulation.
“This technology enables the targeting of acoustic energy, even far away from the transducer array, something which is not possible with electrical stimulation,” Associate Professor Collins said.
Professor Nicholas Opie, Founding Director of Synchron and Head of the Vascular Bionics Laboratory within the University of Melbourne Department of Medicine, developed the company’s Stentrode technology, which allows people with paralysis to use their thoughts to control a digital device. The Stentrode records from the brain without open brain surgery, using electrodes placed inside a blood vessel. Stentrode clinical trials are under way, with the first participant receiving the device in 2019.
“We have demonstrated preliminary safety and efficacy of implanting neurotechnology within cortical blood vessels to enable people with paralysis to control external equipment with their minds,” Professor Opie said.
“Ultrasound is a new method of stimulating the brain and has the potential to provide transformative treatments for people with neurological disorders such as Parkinson’s, epilepsy and depression.”
The team hopes to achieve a successful world-first demonstration of this new brain stimulation technique during the three-year project. If successful, they hope the first human trial could begin in 2030.
Research team members Professor David Grayden, Dr Jack Drummond, Associate Professor Sam John, Professor Anthony Burkitt and Associate Professor David Collins are all based in the Faculty of Engineering and Information Technology’s Department of Biomedical Engineering. Professor Nicholas Opie is based within the Faculty of Medicine, Dentistry and Health Sciences.