Australian neurologists are to present findings at the American Academy of Neurology 2022 meeting from the first four patients with ALS treated with a novel endovascular brain implant.
The results show that implantation of the brain-computer interface (BCI) wireless device allowed participants with paralysis to transmit signals to digital devices and thus regain control over some activities of daily living.
Patient used the ambulatory motor neuroprosthesis in conjunction with eye-tracking to control software and independently conduct remote communication, online shopping and banking tasks.
Professor Bruce Campbell of the University of Melbourne says the pilot program is investigating the feasibility, safety and efficacy of implanting an ambulatory motor neuroprosthesis using an endovascular stent-electrode array to transmit electrocorticography signals from the motor cortex for digital device control in ALS patients with flaccid upper limb paralysis.
The program was led by Dr Thomas Oxley and a neurosurgical team at the Vascular Bionics Laboratory of the Melbourne Brain Centre at the Royal Melbourne Hospital. While breakthrough implant research was done based on burr hole craniotomy, they now have results from the first four people with ALS to have the device implanted within the brain by endovascular surgery.
According to a previously published protocol, the brain-computer interface is fed through one of two jugular veins in the neck into a large blood vessel in the brain.
The device, comprised of a net-like material with 16 sensors attached, expands to line the vessel wall. That device is connected to an electronic device in the chest that then relays the brain signals from the motor cortex, the part of the brain that generates signals for movement, into commands for a laptop computer.
The Stentrode device, was implanted immediately adjacent to the precentral gyrus from the superior sagittal sinus via the left jugular vein.
The results to be presented at the AAN meeting in Seattle on 5 April show that after one year of follow up of participants the device was safe, with no serious adverse events that led to disability or death. The device also stayed in place for all four people and the blood vessel in which the device was implanted remained open.
The team also examined whether participants could use the brain-computer interface to perform routine digital tasks. All participants were able to learn how to use the device with eye tracking to use a computer.
A decoder developed during the study allowed one study participant to control a computer independently without an eye tracker. The machine-learning decoder was programmed so that when a trainer asked participants to attempt certain movements, like tapping their foot or extending their knee, the decoder analysed nerve cell signals from those movement attempts.
The decoder was able to translate movement signals into computer navigation.
“Our research is exciting because while other devices require surgery that involves opening the skull, this brain-computer interface device is much less invasive. It receives electrical signals from the brain, allowing people to control a computer by thought,” said Professor Campbell in a statement released by the AAN.
“Our research is still new, but it holds great promise for people with paralysis who want to maintain a level of independence,” he said.
“We are continuing this research in Australia as well as in the United States in larger groups of people.”
The study was supported by Synchron Inc., the maker of the Stentrode device, the NHMRC and the Motor Neurone Disease Research Institute of Australia.