Assessment of Safety of a Fully Implanted Endovascular Brain-Computer Interface for Severe Paralysis in 4 Patients

Abstract

ImportanceBrain-computer interface (BCI) implants have previously required craniotomy to deliver penetrating or surface electrodes to the brain. Whether a minimally invasive endovascular technique to deliver recording electrodes through the jugular vein to superior sagittal sinus is safe and feasible is unknown.ObjectiveTo assess the safety of an endovascular BCI and feasibility of using the system to control a computer by thought.Design, Setting, and ParticipantsThe Stentrode With Thought-Controlled Digital Switch (SWITCH) study, a single-center, prospective, first in-human study, evaluated 5 patients with severe bilateral upper-limb paralysis, with a follow-up of 12 months. From a referred sample, 4 patients with amyotrophic lateral sclerosis and 1 with primary lateral sclerosis met inclusion criteria and were enrolled in the study. Surgical procedures and follow-up visits were performed at the Royal Melbourne Hospital, Parkville, Australia. Training sessions were performed at patients’ homes and at a university clinic. The study start date was May 27, 2019, and final follow-up was completed January 9, 2022.InterventionsRecording devices were delivered via catheter and connected to subcutaneous electronic units. Devices communicated wirelessly to an external device for personal computer control.Main Outcomes and MeasuresThe primary safety end point was device-related serious adverse events resulting in death or permanent increased disability. Secondary end points were blood vessel occlusion and device migration. Exploratory end points were signal fidelity and stability over 12 months, number of distinct commands created by neuronal activity, and use of system for digital device control.ResultsOf 4 patients included in analyses, all were male, and the mean (SD) age was 61 (17) years. Patients with preserved motor cortex activity and suitable venous anatomy were implanted. Each completed 12-month follow-up with no serious adverse events and no vessel occlusion or device migration. Mean (SD) signal bandwidth was 233 (16) Hz and was stable throughout study in all 4 patients (SD range across all sessions, 7-32 Hz). At least 5 attempted movement types were decoded offline, and each patient successfully controlled a computer with the BCI.Conclusions and RelevanceEndovascular access to the sensorimotor cortex is an alternative to placing BCI electrodes in or on the dura by open-brain surgery. These final safety and feasibility data from the first in-human SWITCH study indicate that it is possible to record neural signals from a blood vessel. The favorable safety profile could promote wider and more rapid translation of BCI to people with paralysis.Trial RegistrationClinicalTrials.gov Identifier: NCT03834857

Interim Safety Profile From the Feasibility Study of the BrainGate Neural Interface System

“…35 Chronically implanted electrocorticography grids have been placed for similar research in the United States and The Netherlands, 31,36 and 4 investigational Stentrode devices have been placed in Australia. 37,38 Several neurotechnology companies are also preparing clinical trials of implanted BCI systems, reinforcing the growing interest in developing and deploying a clinically useful implanted BCI.…”

Decoding the business of brain–computer interfaces

“…Also relatively simple -compared with neurosurgery -is the insertion procedure, which is done as an outpatient procedure, with the device remaining in place indefinitely. so far, seven people living with severe paralysis have had synchron's stentrodes implanted with positive results 6 . The company, says oxley, is in discussions with the FdA about a path to clinical approval.…”

Functional material-mediated wireless physical stimulation for neuro-modulation and regeneration

“…151 In addition, Stentrode, an FDA-approved endovascular miniaturized neural interface, can record and stimulate the brain with a blood vessel and has been proven safe and effective in clinical practice, offering hope to patients with severe paralysis. 152 Magnetic fields and ultrasound are wireless, but they lack the ability to selectively target and stimulate cells. While the emergence of optogenetics, sonogenetics and thermogenetics provides more precise stimulation strategies, their reliance on genetic modification of cells to express specific ion channels remains a common limitation that cannot be ignored.…”