Closed-Loop Intracortical Stimulation Alleviates Locomotor Deficits After Spinal Cord Injury

Abstract

Thoracic spinal cord injury disrupts the communication between the brain, which controls voluntary movements, and lumbar spinal networks which generate locomotion. When the lesion is incomplete, partial function can be spared or recovered due to spontaneous reorganization of the nervous system. Here we tested whether the rat sensorimotor cortex can control functional movements in the semi-paralyzed leg, early during recovery from spinal cord injury (7-10 days). We designed a neuroprosthetic closed-loop approach whereby neurostimulation is delivered to the sensorimotor cortex timely with leg flexion. The volley of neural activity reaches the lumbar spinal circuits through spared nerve connections and increases the excitation of leg motoneurons, thus resulting in an augmented flexion movement. Our neuroprosthesis immediately alleviated locomotor deficits associated with mild, moderate and severe spinal cord injuries, such as foot dragging.