A quadriplegic man has had limited motion restored to his arm and hand as a result of a novel neuro-prosthesis connected to electrical stimulators in his arm, according to a new study.
The 53-year old patient, who was paralyzed from below the shoulders for 8 years as a result of a bicycle accident, has had enough motion restored to be able to feed himself and drink, according to the study.
Results from the study were published recently in The Lancet.
“Our research is at an early stage, but we believe that this neuro-prosthesis could offer individuals with paralysis the possibility of regaining arm and hand functions to perform day-to-day activities, offering them greater independence. So far it has helped a man with tetraplegia to reach and grasp, meaning he could feed himself and drink. With further development, we believe the technology could give more accurate control, allowing a wider range of actions, which could begin to transform the lives of people living with paralysis,” lead author Dr Bolu Ajiboye of Case Western Reserve University said in a press release.
The individual is the only participant so far in the study, which aimed to circumvent rather than repair the spine using implants to bridge the gap between the patient’s brain and paralyzed limbs.
The patient underwent brain surgery to have a sensor placed in his motor cortex and trained using a virtual reality arm for 4 months before undergoing another procedure to place 36 muscle stimulating electrodes in his upper and lower arm. The stimulators were switched on 17 days post procedure and were used to stimulate muscles to improve strength, movement and reduce muscle fatigue.
After 12 months, the study participant began to work on day to day tasks, starting by watching while a computer operated his arm and thinking of the same actions. Another system recorded the patient’s brain signals to learn to recognize the thoughts, so the systems could be linked to allow the thoughts to control the movement.
The patient was recorded as having successfully drank in 11 out of 12 attempts, taking approximately 20-40 seconds to complete the task.
The participant experienced 4 minor, non-serious adverse events at the time of the study, having had the implant for a total of 717 days, according to the study.
“The goal is futuristic: a paralysed individual thinks about moving her arm as if her brain and muscles were not disconnected, and implanted technology seamlessly executes the desired movement… This study is groundbreaking as the first report of a person executing functional, multi-joint movements of a paralysed limb with a motor neuro-prosthesis. However, this treatment is not nearly ready for use outside the lab. The movements were rough and slow and required continuous visual feedback, as is the case for most available brain-machine interfaces, and had restricted range due to the use of a motorised device to assist shoulder movements… Thus, the study is a proof-of-principle demonstration of what is possible, rather than a fundamental advance in neuro-prosthetic concepts or technology. But it is an exciting demonstration nonetheless, and the future of motor neuro-prosthetics to overcome paralysis is brighter,” Dr Steve Perlmutter of the University of Washington said in a prepared statement.
Study authors said that the device still has some limitations, including that movements made with the device were slower and less accurate than those made with the virtual reality arm used during training. The participant also lost his sense of proprioception when not watching his arm.