Tiny folding implants that expand in the brain after being inserted could make epilepsy operations safer and improve diagnosis for hundreds of patients undergoing surgery every year, scientists believe.
A research team led by the University of Oxford said its electrodes, inspired by the Japanese art of origami, can fit through a small surgical slit about 6mm wide and cover an area five times larger once fully unfurled on the brain surface.
The team, which also included scientists from the University of Cambridge, said this technology could significantly reduce the amount of brain surgery needed for epilepsy patients, while also cutting recovery times and lowering infection risk.
Christopher Proctor, an associate professor at the University of Oxford’s Department of Engineering Science, said the work presents a “new approach” to directly connect with “large areas of the brain through a key-hole like surgery”.
Independent experts have hailed the new technique as “exciting”, saying it offers “real hope” for patients.
Epilepsy, which affects one in 100 people in the UK, is caused by bursts of electrical activity in the brain that temporarily affect how it works, leading to frequent seizures.
The hope is that the origami-like probes will help pinpoint where these seizures originate within the brain, offering a safer and more efficient way to accurately diagnose the condition when other tests have failed.
At present, there are mainly two types of surgeries performed to monitor electrical activity in the brain: electrocorticography (ECoG) and stereoelectroencephalography (SEEG).
ECoG procedures are highly invasive, often requiring surgeons to cut out a large window in the skull to place electrodes directly on to the brain surface, and hence not routinely performed.
SEEG surgeries are less invasive – with an estimated 200 operations carried out in the UK every year – but the noodle-like probes only cover a very small surface area of the brain, instead penetrating deeper into the tissue.
Damiano Barone, a neurosurgeon and clinical lecturer at the University of Cambridge, said the folding electrodes could potentially be used in combination with SEEG probes to improve epilepsy diagnosis.
A flat, rectangular silicone wafer with 32 embedded electrodes, the device is able to fold up like an accordion, allowing it to pass through a surgical incision about 6mm wide.
Once in position on the brain surface, a pressurised chamber in the wafer filled with fluid inflates and unfolds the device to its original size of 600 square mm.
When tested on pigs, the unfolded electrodes were able to accurately detect and record brain activity, the researchers said.
Dr Barone said the aim is to ultimately “improve the level of diagnostic accuracy in epilepsy and, therefore, (make) safer epilepsy surgery open to a larger number of people.”
Scientists are now looking to refine the device, with the aim to start trials in UK patients within two years.
The team said it is also exploring whether these electrodes could be used to help other patients as well, including those who are paralysed or have lost the ability to speak.
Dr Barone said: “This is a platform technology which offers the possibility to interface with large areas of the brain cortex associated with control, movement, sensation, vision and speech.
“So, it has the potential to restore such function when they have been lost.”
Dr Lawrence Coles, a postdoctoral researcher at the University of Cambridge’s Department of Engineering, said: “Besides epilepsy, this approach could be used to diagnose and treat other conditions that result in brain seizures, such as certain brain tumours.”
Commenting on the research, Tom Shillito, health improvement and research manager at Epilepsy Action, who was not involved in the study, said: “The journey to getting an epilepsy diagnosis can be a complex one, often requiring invasive procedures to record and monitor brain activity and determine follow-up treatment.
“At the same time, people experiencing seizures will also be coming to terms with having a life-changing and fluctuating condition which can, in some cases, be fatal.
“Around 79 people in the UK will learn every day they have epilepsy, so the need for new diagnostic treatments that could lessen that impact and give people a better quality of life has never been greater.
“It’s exciting to hear the positive outcomes of the initial study’s findings which could translate into a really innovative and promising treatment for people with epilepsy – we look forward to seeing how it develops.”
Ley Sander, medical director at the Epilepsy Society and professor of neurology at University College London, who was also not involved, said: “This is an exciting new approach to brain surgery, but it is very much in its infancy.
“Anything that reduces the invasive nature of brain surgery and the risk of infection has to be welcomed, particularly if it promises a shorter recovery time.
“Brain surgery is only possible for people for whom we are able to pinpoint the area of the brain where their seizures occur, but in these cases, it offers real hope of seizure freedom.”
The research is published in the journal Nature Communications.
