Combining low-frequency magnetic stimulation with motor imagery to improve lower limb recovery and motor pathway integrity in cerebral infarction: a randomized, double-blind, and controlled study.

BACKGROUND: Lower limb dysfunction is common after stroke. While physical rehabilitation is the most widely used treatment, its effectiveness is limited in improving motor function. AIM: This study aimed to investigate the effect of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) combined with motor imagery (MI) on lower limb motor dysfunction in cerebral infarction patients. DESIGN: A randomized, double-blind, and controlled study. SETTING: The Rehabilitation Department of a single Hospital. POPULATION: Sixty patients with lower limb motor impairment post-cerebral infarction were randomly allocated to the rTMS group, the MI group, and the combined rTMS + MI group. METHODS: All groups received standard physical rehabilitation training and the allocated treatment for 3 weeks. Motor function was evaluated before and after intervention with the Fugl-Meyer Lower Extremity Motor Function Scale (FMA-LE), Holden Walking Functional Classification (FAC), and Time-Up-Go Time Test (TUGT). Magnetic resonance diffusion tensor imaging (DTI) was used to assess fractional anisotropy (FA) and the bilateral FA ratios (rFA) in the corona radiata, cerebral peduncles, posterior limb of the internal capsule, and infarction foci. RESULTS: The combined treatment increased lower limb motor function (FMA-LE), walking ability (FAC levels), and functional mobility of the lower limb (TUGT), compared to patients receiving MI therapy alone. The combined treatment also had a superior effect to rTMS alone on walking ability. Furthermore, DTI findings demonstrated a more prominent increase in FA and rFA, mainly in the corona radiata, posterior limb of the internal capsule, and the infarcted foci following the combined treatment. CONCLUSIONS: LF-rTMS combined with MI could significantly enhance lower limb motor function in cerebral infarction patients, potentially by promoting neuroplasticity and functional connectivity along the motor pathways. Due to a lack of control group, much of the observed recovery was likely due to spontaneous improvement, given that our patients were in the sub-acute phase of stroke with mild to moderate motor impairment. CLINICAL REHABILITATION IMPACT: This novel therapy provides a promising approach for improving lower limb motor recovery in stroke rehabilitation.