To assess the therapeutic effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) on motor dysfunction in patients with ischemic stroke using diffusion tensor imaging (DTI), and to explore the underlying neural mechanism of high-frequency rTMS for motor dysfunction.

Forty patients with ischemic stroke admitted to Neurology Department, Brain Center and Neurorehabilitation Center of Baotou Central Hospital from October 2023 to December 2024 were collected, and divided into treatment group and control group by the random number table method, with 20 cases in each group. Both groups received basic pharmacotherapy and conventional rehabilitation. On this basis, the treatment group underwent high-frequency (10 Hz) rTMS for 4 weeks, 5 times a week, 15 min each time. The control group received 10 Hz sham stimulation. DTI examinations and functional assessments using the National Institutes of Health stroke scale (NIHSS), Fugl-Meyer assessment (FMA), and modified Barthel index (MBI) were performed on the day of the first and last treatment sessions to evaluate neurological deficit severity, limb motor impairment, and activities of daily living. Regions of interest (ROIs) for DTI were placed in the corona radiata and posterior limb of the internal capsule. Fractional anisotropy (FA) values in each ROI were recorded, and relative FA (rFA) was calculated. Rehabilitation scale scores and DTI metrics before and after treatment were compared between the two groups.

After 4 weeks of treatment, the NIHSS scores of both groups decreased compared to those before treatment, with a more significant decrease in the treatment group, and the differences were statistically significant (P<0.05). Both FMA and MBI scores increased compared to those before treatment, with a more significant increase in the treatment group, and the differences were statistically significant (P<0.05). The FA and rFA values of the radiating coronary region and posterior limb of the internal capsule in the treatment group increased compared to those before treatment, and the differences were statistically significant (P<0.05). However, there was no statistically significant difference in the FA and rFA values between the control group before and after treatment (P>0.05).

High-frequency rTMS combined with conventional rehabilitation therapy can significantly improve motor dysfunction in patients with ischemic stroke and improve the integrity of the corticospinal tract on the affected side, which may represent the neural mechanism underlying the therapeutic effect of high-frequency rTMS on post-stroke motor dysfunction.