fNIRS ‐Based Network Signatures of Sensory‐Primed Bilateral Arm Training in Subacute Stroke Recovery

SIGNIFICANCE: This study leverages functional near-infrared spectroscopy (fNIRS) to elucidate optically derived cortical network signatures underlying combined sensory-motor interventions in stroke rehabilitation. AIM: To characterize the synergistic effects of peripheral electrical stimulation (PES) and bilateral arm training (BAT) on cortical hemodynamics and functional network architecture using fNIRS. APPROACH: fNIRS signals were acquired from 24 subacute stroke patients. Wavelet amplitude and wavelet phase coherence were employed to quantify task-related hemodynamic activation and interregional synchronization within the 0.01-0.08 Hz frequency band. RESULTS: Compared with BAT alone, the PES-BAT paradigm elicited augmented hemodynamic activation in ipsilesional prefrontal and motor regions. The combined intervention further enhanced phase synchronization across distributed cortical networks and preserved interhemispheric coherence, counteracting maladaptive contralesional dominance. CONCLUSIONS: The fNIRS-based wavelet metrics effectively detect intervention-dependent modulation of cortical hemodynamics and network organization, highlighting the value of optical neuroimaging in assessing neuroplasticity during stroke rehabilitation.