Journal Article

Restoring cortical control of functional movement in a human with quadriplegia

Deogaonkar, Milind, Nielson, Dylan M., Annetta, Nicholas V., Friedenberg, David A., Bockbrader, Marcia A., Shaikhouni, Ammar, Sederberg, Per B., Sharma, Gaurav, Mysiw, W. Jerry, Morgan, Austin G., Rezai, Ali R., Bouton, Chad E., Glenn, Bradley C.

2016

Overview

Signals recorded from motor cortex—through an intracortical implant—can be linked in real-time to activation of forearm muscles to restore movement in a paralysed human. Part restoration of muscle response in quadriplegia This paper demonstrates that signals recorded from motor cortex — through an intracortical implant — can be linked in real-time to activation of forearm muscles in order to restore movement in a paralysed human. Motor cortex signals were decoded and used to control a neuromuscular electrical stimulation system contained in a sleeve wrapped around the patient's arm. The system provided isolated finger movements and the patient, a 24-year-old male who had sustained a spinal cord injury, could make six different volitional wrist and hand motions, enabling him to grasp, manipulate and release objects. Millions of people worldwide suffer from diseases that lead to paralysis through disruption of signal pathways between the brain and the muscles. Neuroprosthetic devices are designed to restore lost function and could be used to form an electronic ‘neural bypass’ to circumvent disconnected pathways in the nervous system. It has previously been shown that intracortically recorded signals can be decoded to extract information related to motion, allowing non-human primates and paralysed humans to control computers and robotic arms through imagined movements 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . In non-human primates, these types of signal have also been used to drive activation of chemically paralysed arm muscles 12 , 13 . Here we show that intracortically recorded signals can be linked in real-time to muscle activation to restore movement in a paralysed human. We used a chronically implanted intracortical microelectrode array to record multiunit activity from the motor cortex in a study participant with quadriplegia from cervical spinal cord injury. We applied machine-learning algorithms to decode the neuronal activity and control activation of the participant’s forearm muscles through a custom-built high-resolution neuromuscular electrical stimulation system. The system provided isolated finger movements and the participant achieved continuous cortical control of six different wrist and hand motions. Furthermore, he was able to use the system to complete functional tasks relevant to daily living. Clinical assessment showed that, when using the system, his motor impairment improved from the fifth to the sixth cervical (C5–C6) to the seventh cervical to first thoracic (C7–T1) level unilaterally, conferring on him the critical abilities to grasp, manipulate, and release objects. This is the first demonstration to our knowledge of successful control of muscle activation using intracortically recorded signals in a paralysed human. These results have significant implications in advancing neuroprosthetic technology for people worldwide living with the effects of paralysis.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/378/2632/2634 / 631/61 / Activities of Daily Living / Algorithms / Cervical Cord - injuries / Cervical Cord - physiology / Cervical Cord - physiopathology / Electric Stimulation / Electrodes, Implanted / Forearm - physiology / Hand - physiology / Hand Strength - physiology / Health aspects / Humanities and Social Sciences / Humans / Imagination / letter / Machine Learning / Magnetic Resonance Imaging / Male / Microelectrodes / Motor Cortex - physiology / Movement - physiology / multidisciplinary / Muscle, Skeletal - physiology / Physiological aspects / Quadriplegia / Quadriplegia - etiology / Quadriplegia - physiopathology / Science / Spinal Cord Injuries - complications / Spinal Cord Injuries - physiopathology / Young Adult