January 2020 | Issue 36 Demetrius Lopes:
Surface modification
Page 4
Robert M Levy:
Jason Pope:
Profile
Centres of excellence
Page 16
World’s first robotic-assisted brain surgery provokes possibility of remote stroke care Physicians in Toronto, Canada, have performed the world’s first-in-human robotic-assisted brain surgery, using Corindus’ robotic system. In the future, advocates of the robot hope that it will enable experts to remotely operate on stroke and aneurysm patients. Vitor Mendes Pereira, Joint Department of Medical Imaging and Krembil Brain Institute at Toronto Western Hospital, who led the team through this stent-assisted aneurysm coiling case, speaks to NeuroNews about how communication within this new workflow is the greatest challenge, and enthuses about the prospect of remote stroke procedures.
Page 22
“W
e were thrilled to have the opportunity to perform this first case. Robotics adds a lot of precision to neuroendovascular procedures, particularly during stent deployment. In this perspective, what is also exciting is the possibility of performing remote procedures. “Here in Canada, we have a big problem; we have a country that is too wide, with some populations living around 10 hours away from stroke centres. So for us, the robotic system has huge potential to improve access to care.” Pereira posits that the ultimate goal is to acquire a central hub, as the team in Toronto is currently organising for some centres in remote cities of Canada to become capable of remote procedures. So far, some hospitals in Canada are already set up with the telestroke programme—according to Pereira—meaning they are already connected to the stroke network, enabling an easier transition to remote capabilities. Remote proctoring is also something that will help diffuse knowledge, says Pereira, and subsequently increase the quality of procedures in general. He adds that when coaching a trainee, it will be very easy to take over if they ever begin to feel uncomfortable. While the possibility of remote procedures is “one of the most exciting objectives”, Pereira says that other advantages of a robotic system include improved procedural precision at the bedside. “I have a lot of experience with intracranial stents, and perhaps few physicians could place it exactly where they want it. But with the robot, every time, you can precisely—with millimetre precision—deploy the stent.”
Procedural success
Having acquired Corindus’ CorPath GRX in August 2019, Pereira reports that the team conducted an array of tests, and that, in the four months leading up to the first-in-human case, the team performed at least two
Vitor Mendes Pereira using the CorPath GRX console
Continued on page 2
Non-invasive targeting of deep brain structures now tested in the human brain Attempting to bridge the gap between invasive and non-invasive brain stimulation modalities, Nir Grossman of Imperial College London, London, UK, introduced delegates at the International Neuromodulation Society’s (INS) 14th World Congress (25–30 May, Sydney, Australia) to a technology that affords the steerable targeting of structures deep inside the brain, without “chemical or genetic modification of the [stimulated] brain tissue”. ACCORDING TO GROSSMAN, the new brain stimulation modality is based on the physical principal of temporal interference. “We deliver multiple electric fields to the brain, at frequencies too high to recruit neural firing, but
which differ by a frequency within the dynamic range of neural firing.” This technique enables the electrical stimulation of neurons throughout a region where interference between the electric fields results in a periodic
change of the envelope amplitude at the difference of the two frequencies. “So, if the first was 1,000Hz, for example, the second could be 1,010 or 1,005Hz. These two currents create electrical fields inside the brain, and these electrical fields are superimposed by the neurones inside the brain.” Grossman told INS delegates that although the physical concept of temporal interference has been known for centuries (it is used to record neuromuscular structure), his team has further developed the concept and made it relevant to the brain. He explained that through temporal interference, it is possible to recruit subcortical structures without the overlying cortex and functionally map a brain region without physically moving the electrodes. Importantly, he highlights: “Temporal
interference does not replace existing brain stimulation modalities, such as [invasive] deep brain stimulation, or non-invasive transcranial current stimulation. Instead, it adds new capabilities to the existing ecosystem of brain stimulation.”
We deliver multiple electric fields to the brain, at frequencies too high to recruit neural firing.” Continued on page 21