Spinal Cord Stimulation Immediately Improves Strength, Arm Function and Reduces Spasticity in People With Chronic Post-Stroke Upper Limb Hemiparesis.

Here, we report the final outcomes of a pilot clinical trial testing preliminary efficacy and safety of cervical epidural spinal cord stimulation (SCS) for chronic post-stroke upper-limb hemiparesis (NCT04512690). We implanted seven participants with profound motor deficits (Fugl-Meyer Assessment [FMA] scores 15-35) using two leads implanted unilaterally in the cervical spinal cord for 4 weeks. Under SCS ON, motor function immediately improved regardless of impairment severity (average +32% strength and +5.6 FMA-points). Notably, 3/7 participants with residual corticospinal connectivity to finger muscles regained hand/finger function with SCS. Despite performing only 8.6hrs of motor activity (5.5hrs with SCS ON), participants improved by average +6.6 FMA-points at the end of the study compared to baseline and spasticity decreased in all participants. While all benefited, our preliminary analysis indicates that spared sensory function may be a determinant of responsiveness to SCS. No serious adverse events occurred.