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

Background and Objectives: Brain computer interfaces (BCIs) are being developed to restore mobility, communication, and functional independence to people with paralysis. Though supported by decades of preclinical data, the safety of chronically implanted microelectrode array BCIs in humans is unknown. We report safety results from the prospective, open-label, non-randomized BrainGate feasibility study (NCT00912041), the largest and longest-running clinical trial of an implanted BCI.

Methods: Adults aged 18-75 with quadriparesis from spinal cord injury, brainstem stroke, or motor neuron disease were enrolled through seven clinical sites in the United States. Participants underwent surgical implantation of one or two microelectrode arrays in the motor cortex of the dominant cerebral hemisphere. The primary safety outcome was device-related serious adverse events requiring device explanation or resulting in death or permanently increased disability during the one-year post-implant evaluation period. Secondary outcomes include the type and frequency of other adverse events as well as the feasibility of the BrainGate system for controlling a computer or other assistive technologies.

Results: From 2004 – 2021, fourteen adults enrolled in the BrainGate trial had devices surgically implanted. The average duration of device implantation was 872 days, yielding 12,203 days of safety experience. There were 68 device-related adverse events, including 6 device-related serious adverse events. The most common device-related adverse event was skin irritation around the percutaneous pedestal. There were no safety events that required device explantation, no unanticipated adverse device events, no intracranial infections, and no participant deaths or adverse events resulting in permanently increased disability related to the investigational device.

Discussion: The BrainGate Neural Interface system has a safety record comparable to other chronically implanted medical devices. Given rapid recent advances in this technology and continued performance gains, these data suggest a favorable risk/benefit ratio in appropriately selected individuals to support ongoing research and development.

Trial Registration Information: ClinicalTrials.gov Identifier: NCT00912041.

Classification of Evidence: This study provides Class IV evidence that the neurosurgically placed BrainGate Neural Interface system is associated with a low rate of SAEs defined as those requiring device explanation, resulting in death, or resulting in permanently increased disability during the one-year post implant period.