The Cortical Motor Map for the Extensor Digitorum Communis Muscle Fails to Increase in Treatment-Related Clinically Significant Upper Limb Post-Stroke Recovery

Authors

• Tomoko Kitago, Burke Neurological Institute
• Joshua Silverstein, Burke Neurological Institute
• Michael B. Gerber, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell
• Charlene Thomas, Weill Cornell Medicine
• Linda M. Gerber, Weill Cornell Medicine
• Gary W. Thickbroom, Weill Cornell Medicine
• Dylan J. Edwards, Burke Neurological Institute

DOI

10.1016/j.transm.2025.100186

Journal Title

Transcranial Magnetic Stimulation

Document Type

Article

Publication Date

8-1-2025

Department

Neurology

Keywords

Mapping, Recovery, Rehabilitation, Stroke, Transcranial magnetic stimulation

Disciplines

Medicine and Health Sciences

Abstract

Objectives: Cortical reorganization has been proposed as a mechanism for motor recovery of the upper limb. The objective of this study was to determine if intervention-related clinical improvement in post-stroke hemiparesis is associated with enlarged motor cortex representation. Methods: Data were analyzed from a single site subset of the NICHE trial. Clinical assessments of upper limb movement (Fugl-Meyer Upper Extremity Motor Assessment, FM-UE, Action Research Arm Test, ARAT, and Wolf Motor Function Test, WMFT) and transcranial magnetic stimulation (TMS) motor mapping of the extensor digitorum communis (EDC) muscle were performed in 23 participants (3–12 months post-stroke, 10 female, 40–88 yrs) before and after intervention. Results: Improvement in FM-UE was statistically and clinically significant (mean pre= 38±15), post= 45±16); p < 0.001). Significant improvement was also observed on ARAT and WMFT. Ipsilesional hemisphere map volume (MV) remained unchanged (p = 0.36). The magnitude of clinical benefit was unrelated to differences in map characteristics from pre to post (Spearman's rho= 0.06, p = 0.79). Conclusions: Intervention-related clinical improvements using standardized tests of the upper limb may not solely rely on consistent changes in the cortical motor representation. The role of upper limb cortical representation may need to be examined with other structural and functional investigational methods in the context of a broader brain network of recovery supporting upper limb motor function.

Recommended Citation

Kitago, T., Silverstein, J., Gerber, M., Thomas, C., Gerber, L., Thickbroom, G., & Edwards, D. (2025). The Cortical Motor Map for the Extensor Digitorum Communis Muscle Fails to Increase in Treatment-Related Clinically Significant Upper Limb Post-Stroke Recovery. Transcranial Magnetic Stimulation, 4. https://doi.org/10.1016/j.transm.2025.100186