Effects of Intermittent Theta Burst Stimulation Combined with Low-Frequency Repetitive Transcranial Magnetic Stimulation on Patients with Upper Limb Motor Dysfunction After Stroke

<bold>Objective</bold>To investigate the effects of intermittent theta burst stimulation (iTBS) combined with low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on upper extremity motor function in post-stroke patients.<bold>Methods</bold>Thirty-two stroke patients treated at Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine from April to December 2023 were selected and randomly divided into an observation group and a control group, with 16 patients in each group. During the treatment, one patient in the control group dropped out due to a new medical condition, and one in the observation group dropped out due to unwillingness to cooperate with post-intervention assessment, resulting in 15 patients being ultimately included in each group. The observation group received LF-rTMS and iTBS in addition to conventional stroke rehabilitation and medication. LF-rTMS was applied to the M1 area of the unaffected hemisphere at 80% of the resting motor threshold for 20 minutes; iTBS was applied to the SMA area of the affected hemisphere at 80% of the active motor threshold for 3 minutes. The treatment was administered once daily for 10 consecutive days. The control group received LF-rTMS and sham iTBS with identical devices and parameters alongside conventional rehabilitation and medication. The Fugl-Meyer Assessment Upper Extremity (FMA-UE) score was used to evaluate upper limb motor function one day before and one day after the 10-day treatment. Functional near-infrared spectroscopy (fNIRS) was used to monitor changes in oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) concentrations. Adverse events such as headache, dizziness, and seizures were observed.<bold>Results</bold>(1) FMA-UE scores: Compared to pre-treatment, both groups showed significant increases in FMA-UE scores post-treatment (P&lt;0.05). The observation group's post-treatment FMA-UE score was significantly higher than that of the control group (P &lt; 0.05). (2) Effective connectivity between brain regions: In the control group, effective connectivity from the affected SMA to the unaffected SMA was significantly enhanced after treatment (P &lt; 0.05). In the observation group, effective connectivity from the affected M1 to the unaffected DLPFC was significantly weakened after treatment (P &lt; 0.05). Compared to the control group, the observation group showed significantly stronger post-treatment effective connectivity from the bilateral DLPFC, unaffected SMA, and unaffected M1 to the affected M1, as well as from the unaffected SMA to the unaffected M1 and affected SMA (P &lt; 0.05). (3) Safety: No adverse events, such as epilepsy or headache, occurred in any patient during the treatment.<bold>Conclusion</bold>The combination of iTBS and LF-rTMS can improve upper extremity motor function in stroke patients with a good safety profile, making it worthy of clinical application. The mechanism may be related to regulating neural circuit remodeling and promoting functional reorganization of the motor cortex.