Cortical response and functional connectivity in subacute stroke patients during dual task: An fNIRS study.

Abstract

To investigate neural plasticity changes in subacute stroke patients during single motor task and dual-task execution. Case-control study. Rehabilitation department in a single hospital. Twenty subacute stroke patients (mean age 63.8±10.4 years; Mini-Mental State Examination score >20) and 20 age- and sex-matched healthy controls (mean age 60.95±9.5 years) recruited via convenience sampling. Not applicable. a fNIRS system was used to evaluate hemodynamic responses in prefrontal, motor, and occipital regions during single motor task and motor-cognitive dual-task conditions, and functional connectivity (FC) was calculated for each task state. Healthy controls showed widespread activation increases during dual-task versus single motor task (p<0.05), while stroke patients exhibited enhanced activation only in ipsilesional prefrontal cortex (p=0.041) and contralesional supplementary motor area (p=0.045). Controls demonstrated significantly higher sensorimotor activation than stroke patients during dual-task (p=0.001). FC analysis revealed increased prefrontal-premotor connectivity in controls (p=0.027), whereas stroke patients showed enhanced bilateral prefrontal (p=0.032), premotor (p=0.034), and occipital (p=0.043) connectivity. Stroke patients' premotor area activation negatively correlated with pace (ρ=-0.53, p=0.025), heel-strike angle (ρ=-0.73, p=0.029), and swing phase (ρ=-0.56, p=0.015), but positively with support phase (ρ=0.56, p=0.015). This study confirms that motor-cognitive dual task paradigms effectively induce activation in the ipsilesional cortex of stroke patients while enhancing interhemispheric functional connectivity, demonstrating significant neuromodulatory effects of dual-task training in stroke rehabilitation; simultaneously, it validates the feasibility of utilizing fNIRS combined with motor paradigms for real-time assessment of neuroplasticity changes.