Insight

 The promise of neurotechnology 

Neurotechnology-based therapies, including brain-machine interfaces, robotics, and brain stimulation, have been touted as potential game-changers for people with neurological disorders. Abi Millar takes a look at the state of neurotechnology, and how innovative treatments are already benefitting patients.

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eurotechnology-based therapies – once the preserve of science fiction – are fast becoming a reality. Including the likes of neurostimulation and brain-machine interfaces, the field blurs the lines between technology and biology. It could prove a game-changer for many patients, as well as holding profound implications for society at large.

In July, it was reported that a two-year-old Scottish girl had become the youngest person ever to receive deep brain stimulation (DBS). The child, who suffers from a rare genetic disorder, was experiencing out-of-control muscle spasms (dystonia) and would have died without surgery.

Surgeons at the Evelina Children’s Hospital in London implanted two electrodes (neurostimulators) into the globus pallidus internus, a region of the brain responsible for preventing unwanted movement. The contacts on the electrodes send electric pulses down the wires and towards a pacemaker-device inserted under the skin of the abdomen. Over time, this helps reduce the uncontrollable movements and holds the promise that the child will lead a normal life.

“In operating on Viktoria our neurosurgeons have broken the sound barrier in neurosurgery, by offering DBS at such a young age,” said Dr Jean-Pierre Lin, the child’s consultant paediatric neurologist. “Viktoria’s case is exciting and potentially very significant because it may offer an opportunity for children with early movement disorders to benefit from DBS and have a better future.”

Other cases of this nature aren’t hard to find. Elon Musk’s Neuralink company, which hopes to implant devices in paralysed people, recently unveiled some of its technology to the public. Musk revealed that in tests, a monkey had been able to control a computer with its brain.

A wave of neurotech startups, at various stages of development, are looking to do everything from predicting an athlete’s potential to treating depression. And in September, two researchers (publishing their perspective in Nature Biotechnology) argued that neurotechnology is on the cusp of a major breakthrough, following the development of ultra-flexible brain-machine interfaces that could minimise the patient’s immune response.

Since around a billion people worldwide have a brain disorder of some sort, it’s easy to see how neurotechnology could usher in possibilities so far undreamed of, as well as prompting new philosophical, ethical and legal questions.

Implants, neurofeedback and brain radios

The Wyss Center, an independent translational research centre in Geneva, Switzerland, works to accelerate neurotechnology for human benefit. As Dr Tracy Laabs, deputy director, explains, while technology development is moving quickly, there are still a number of challenges to iron out.

“You need to build a system that’s biocompatible, biostable and fully hermetic – the body is quite a hostile environment so something that has electronics inside it has to be completely watertight,” she explains. “One of the major challenges of developing implantable devices that can measure brain signals is securely encapsulating the device in a protective biocompatible coating that will allow it to function in the body for years.”

You need to build a system that’s biocompatible, biostable and fully hermetic.

The Wyss Center has a number of projects underway that could translate research ideas into clinical solutions. One is an implantable device for people with epilepsy – flexible electrodes that slip under the skin of the scalp and provide continuous, wireless monitoring of their brain activity. With clinical trials planned for 2020, the device could eventually send seizure forecasts to a mobile phone.

Another is a neurofeedback device for people with tinnitus, to help them reduce the intensity of the ringing sound in their ears. Still another is an implantable brain radio.

“This is a high bandwidth brain radio that will enable the wearer to transfer data from their brain to a computer,” says Laabs. “Ultimately this could be used for stroke populations, as well as for people with epilepsy and locked-in syndrome.”

A personalised approach to stroke

The centre is also looking into personalised stroke rehabilitation – a combination strategy that may improve on existing therapies. As Dr Martina Coscia, staff engineer, explains, patients with chronic severe stroke are not best served by a one-size-fits-all approach.

“Stroke is very heterogeneous, meaning if we want to develop an intervention for these patients, we’re not going to see a very strong benefit because there will be some individuals who respond and some who don’t, she says. “We need to be more precise and think about solutions that suit the individual.”

In July, Coscia and co-authors published a paper in the journal Brain, which made the case for personalised stroke therapies. The paper compared 64 clinical trials and studies, all of which explored neurotechnology-aided treatments for rehabilitation of the arm after stroke.

“There are several neurotechnologies currently available for rehabilitation of the arm for stroke patients – these include robotics, muscular electrical stimulation, brain stimulation, brain computer interfaces (BCI), virtual reality, wearable and tracking devices,” says Coscia. “We found that solutions for individuals with severe upper limb disability after stroke are not widespread. It is a field where a lot can be still done.”

We need to be more precise and think about solutions that suit the individual.

The team is now planning a trial to see how multiple approaches might be used in combination. Scheduled to start in Switzerland in October, the trial will test the safety and efficacy of various neurotechnologies on a small population of patients.

“We will start with BCI, robotics and muscular stimulation, and will measure the extent to which motor recovery improves,” says Coscia. “We will continue with the use of these neurotechnologies until the individual stops improving. If they do not progress we will add brain stimulation to see if this boosts the effect of treatment and we will continue to monitor motor recovery. We hope the trial will provide a proof of concept of a personalised approach.”

As Laabs explains, there are a number of groups around the world that have been trying to build a brain-computer interface for neurorehabilitation.

“The thought is that if you’re able to measure when someone’s intending to move, and you couple that measurement with a time-coordinated movement that’s aided either with a robot or electrical simulation, you can provide suitable controlled sensory feedback linked to intention which promotes a more natural rehabilitation strategy,” she says. “It might lead to some neuroplasticity, strengthening any pathways in the brain that may still be remaining after the stroke.”

Of course, we are not yet at a point where neurotechnologies are in common use, particularly those that can be used outside of clinical settings. However, with research continuing apace we appear to be getting close to some major breakthroughs.