Intrinsic functional architecture predicts remote motor cortical excitability changes induced by intermittent...

Repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability both locally and remotely through connected regions. However, how intrinsic functional architecture influences these remote effects remains unclear. Leveraging multi-site stimulation (targeting the left primary motor cortex [M1], dorsal premotor cortex, and caudal inferior parietal lobule) combined with resting-state functional magnetic resonance imaging, we investigate whether intrinsic functional architecture predicts rTMS-induced changes in contralateral M1 excitability. While group-level effects were absent, individual variability in excitability changes was significantly predicted by functional characteristics. When the engaged network of stimulated region is sensorimotor network, resting-state functional connectivity between the stimulated region and the right M1 significantly predicts excitability changes, moderated by within-network interactions. Otherwise, exploratory analysis found associations with network topological properties rather than direct coupling. These findings provide preliminary insights into rTMS neuromodulation and may inform future development of personalized treatments (e.g., for post-stroke motor rehabilitation), yet require further investigation in clinical populations.