Efficacy of dual-target iTBS on gait function and brain activation in stroke patients: a randomized, single-blinded,...

This study aimed to assess the efficacy of intermittent theta burst stimulation (iTBS) applied to the lower limb motor cortex and the contralateral cerebellar hemisphere, both individually and in combination, on walking function in stroke patients. Secondarily, the study analyzed the effects of iTBS on brain functional connectivity across the three groups.

A total of 63 participants were randomly assigned to one of three groups, with 21 participants in each group: a sham stimulation group, a single-target iTBS group that stimulated the affected lower limb motor cortex, and a dual-target iTBS group that stimulated both the affected lower limb motor cortex and the contralateral cerebellum. All participants received conventional rehabilitation therapy alongside the iTBS treatment. The iTBS was administered daily at 80% of the motor evoked potential for 21 consecutive days. Outcomes were measured using the Modified Barthel Index (MBI), the Fugl-Meyer Assessment for lower extremity (FMA-LE), and the Berg Balance Scale (BBS). Additionally, three-dimensional gait analysis and functional near-infrared spectroscopy (fNIRS) were utilized to evaluate gait parameters and brain network function.

Following the intervention, the dual-target iTBS group exhibited significantly greater improvements in lower limb motor function (FMA-LE) and balance (BBS) compared to both the single-target and sham groups. In gait analysis, the dual-target group demonstrated superior enhancements in key parameters, including step length and swing phase, relative to the single-target group, and achieved broader gains across gait metrics when compared to the sham group. Furthermore, fNIRS analysis revealed enhanced prefrontal-lower limb motor cortex connectivity and network efficiency only in the dual-target group, which correlated with improved gait outcomes.

Simultaneous iTBS targeting the affected lower limb motor cortex and the contralateral cerebellar motor region is more effective than single-target stimulation in enhancing lower limb motor function and balance in stroke patients. This enhanced efficacy may arise from the activation of cortical-cerebellar circuits, which improves brain network efficiency and results in better gait outcomes.