Targeted epidural electrical stimulation for improving motor in a chronic stroke patient with severe upper limb paresis

Introduction: The dreadfully restricted hand and arm movement often prevents chronic stroke patients from regaining functional activity, and there is limited strategy to solve this problem. Short-term epidural electrical stimulation (EES) has emerged as a promising technique, tapping into the potential to reorganize the disrupted neural circuits and subsequently enhance post-stroke motor function.

Methods: In our pilot study, a chronic stroke patient who had a left putaminal ICH with a pronounced upper limb impairment underwent two distinct phases of EES. Electromyography (EMG) recordings failed to exhibit any detectable activity before EES trial. Initially, a temporary epidural stimulation was targeting patient's C4 to T1 spinal segments. Observing immediate elbow flexion and EMG recordings over biceps under stimulation, we progressed to the second phase, wherein a permanent EES implant was affixed to the patient's C5 to C7 segments. Physiological and clinical assessments were carried out using tools by EMG, sTMS as well as the Fugl-Meyer motor assessment, modified ashworth scale, Barthel index, and Action Research Arm Test. fMRI was performed to identify the evolution of cortical activation.

Results: We implanted a permanent epidural stimulation electrode over the cervical spinal cord with a pulse generator for a patient suffering from post-stroke near complete upper motor paresis and pain. Neither serious operation-related nor stimulation-related adverse events were encountered. This EES facilitated the restoration of partial upper limb movement. All clinical evaluation scores and EMG readings showed significant increase and staged improvement from proximal to distal muscular control. Albeit the movement was slow, the patient was able to drink water by the 16th week after EES. Furthermore, the fMRI scans displayed remarkably increased activity in the motor cortex over cerebral hemisphere with stroke.

Conclusion : Our findings demonstrate that targeted EES over the cervical cord can improve motor activities with meaningful motor tasks, even in stroke patients with severe corticospinal tract damage. NCT05981989