Beyond IHC-Vicariation duality: precision-stratified rTMS for post-stroke motor recovery

Stroke is the leading cause of long-term disability in adults, and refractory upper extremity motor dysfunction severely compromises patients’ ability to live independently. Repetitive transcranial magnetic stimulation (rTMS), which promotes neuroplasticity by modulating cortical excitability, has emerged as a highly promising therapeutic approach. However, its clinical efficacy exhibits high heterogeneity, mainly because current therapeutic strategies are guided by two seemingly opposing neuroscientific models. The classic Interhemispheric Competition (IHC) model advocates for inhibiting the unaffected hemisphere, while the emerging Vicariation model proposes leveraging compensatory functions of the unaffected hemisphere. This review aims to reconcile this theoretical divergence from a dialectical perspective and propose a biomarker-based individualized stratified treatment framework. The article first systematically reviews the neurophysiological evidence for both models, demonstrating that they are not mutually exclusive but rather applicable to different stages of neurological injury severity. Subsequently, it focuses on elaborating how the structural reserve assessment system, centered on corticospinal tract (CST) integrity and motor evoked potential (MEP), serves as a decision-making fulcrum to guide the selection of rTMS strategies including inhibition, excitation or bilateral modulation. The article proposes an evidence-informed stratification framework and explores the potential synergistic effects of emerging techniques such as theta-burst stimulation (TBS) and peripheral-central combined stimulation. Through multimodal patient stratification, this framework aims to support more individualized and mechanistically informed application of rTMS in post-stroke motor rehabilitation.