Spinal Cord Stimulation Improves Motor Function and Spasticity in 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 to 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.