BRIEF RESEARCH REPORT article
Front. Neurol.
Sec. Stroke
Cervicomedullary motor evoked responses in individuals with severe chronic hemiparesis post-stroke: a feasibility study
Carley L. P. Butler 1,2,3
Aditya Dutt 4
Carolee Winstein 5
Monica Perez 2,1,3
Mary Ellen Stoykov 2,1
1. Northwestern University, Evanston, United States
2. Shirley Ryan AbilityLab, Chicago, United States
3. Edward Hines Junior Veterans Affairs Hospital, Hines, United States
4. Chicago College of Osteopathic Medicine, Downers Grove, United States
5. University of Southern California Division of Biokinesiology and Physical Therapy, Los Angeles, United States
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Abstract
Understanding the neural mechanisms underlying upper limb motor recovery after stroke remains a significant challenge in rehabilitation research. It has been proposed that individuals who show no motor-evoked potential (MEP) response to transcranial magnetic stimulation (TMS) and are thus classified as MEP negative (MEP-) have limited potential for recovery in part due to damage of the corticospinal pathway. In this study, we investigate how individuals categorized as MEP-with TMS respond to stimulation of the corticospinal pathway at a subcortical level. We describe the methodology for eliciting MEPs by using cervicomedullary electrical stimulation (CMEP) in post-stroke individuals with severe upper limb hemiparesis. MEP status (+/-) of the more affected arm was assessed using TMS and cervicomedullary electrical stimulation in stroke survivors with server upper extremity hemiparesis. While most of the participants were classified as MEP-, all individuals were categorized as CMEP+ in the biceps brachii, extensor carpi radialis, and first dorsal interosseous muscles. Importantly, we report the first testing of CMEPs in a small cohort of individuals with stroke. This technique is feasible in this population and has potential for application in clinical translation settings. Our findings provide a foundation for future studies to replicate and expand upon this approach, enabling the exploration of new hypotheses related to post-stroke rehabilitation and recovery.
Summary
Keywords
Cervicomedullary, corticospinal tract, Electrical Stimulation, hemiparesis, motor evoked potential, Stroke
Received
10 October 2025
Accepted
28 January 2026
Copyright
© 2026 Butler, Dutt, Winstein, Perez and Stoykov. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Mary Ellen Stoykov
Disclaimer
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