Regaining arm control is a top priority for people with paralysis. Unfortunately, the complexity of the neural mechanisms underlying arm control has limited the effectiveness of neurotechnology approaches. Here, we exploited the neural function of surviving spinal circuits to restore voluntary arm and hand control in three monkeys with spinal cord injury, using spinal cord stimulation. Our neural interface leverages the functional organization of the dorsal roots to convey artificial excitation via electrical stimulation to relevant spinal segments at appropriate movement phases. Stimulation bursts targeting specific spinal segments produced sustained arm movements, enabling monkeys with arm paralysis to perform an unconstrained reach-and-grasp task. Stimulation specifically improved strength, task performances and movement quality. Electrophysiology suggested that residual descending inputs were necessary to produce coordinated movements. The efficacy and reliability of our approach hold realistic promises of clinical translation.

恢复手臂控制是瘫痪患者的首要任务。不幸的是，手臂控制背后的神经机制的复杂性限制了神经技术方法的有效性。在这里，我们利用脊髓刺激幸存的脊髓回路的神经功能来恢复三只脊髓损伤猴子的自主手臂和手部控制。我们的神经接口利用背根的功能组织，在适当的运动阶段通过电刺激将人工兴奋传递到相关的脊柱节段。针对特定脊柱节段的刺激爆发产生持续的手臂运动，使手臂麻痹的猴子能够执行不受限制的伸手和抓握任务。刺激特别提高了力量、任务表现和运动质量。电生理学表明，剩余的下行输入是产生协调运动所必需的。我们方法的有效性和可靠性为临床转化提供了现实的希望。