Effect Of Repetitive Transcranial Magnetic Stimulation Combined With Repetitive Peripheral Magnetic Stimulation On Upper Limb Motor Function And Cortical Excitability In Stroke Patients

Background:Upper limb motor dysfunction is a common complication of stroke and seriously affects the quality of life of patients.Currently,the effectiveness of rehabilitation of upper limb motor dysfunction in stroke is still unsatisfactory,thus new techniques and methods need to be explored.Repetitive transcranial magnetic stimulation（rTMS）is a non-invasive brain modulation technique that can assist in improving stroke spasticity and motor function.Repetitive peripheral magnetic stimulation（rPMS）is a non-invasive and painless peripheral magnetic stimulation technique that is applied to nerves or muscles.By inducing proprioceptive input,rPMS has a positive effect on the motor dysfunction and the cerebral cortex caused by neurological disorders.Compared with other peripheral interventions,rPMS is a promising therapeutic intervention because of its simplicity,powerful effects,deep penetration and low pain.There are few studies on 1 Hz rTMS combined with rPMS at home and abroad,and lack of objective evaluation indexes.The efficacy and mechanism of 1Hz rTMS combined with rPMS on upper limb motor function after stroke are unclear.Objective:This study used clinical scales,resting motor threshold（r MT）and functional near-infrared spectroscopy（f NIRS）to observe the efficacy of 1 Hz rTMS combined with rPMS on upper limb motor function in stroke.The aim was to observe the efficacy of1Hz rTMS combined with rPMS on upper limb motor function in stroke and the changes of motor cortex excitability and brain activation,and to provide reference for optimizing the rehabilitation strategy of upper limb motor dysfunction after stroke.Methods:35 patients with upper limb dysfunction in stroke admitted to the Department of Rehabilitation Medicine of the Third Affiliated Hospital of Sun Yat-sen University from November 2021 to November 2022 were selected.They were randomly divided into an experimental group（n=17）and a control group（n=18）.Both groups received conventional rehabilitation therapy and low-frequency rTMS on the unaffected hemispheres of the primary motor cortex（M1）.The experimental group received additional rPMS stimulation for the affected triceps brachii and wrist extensors,while the control group received sham rPMS.The treatment was performed once a day,5times a week for 2 weeks.Both groups received Fugl-Meyer assessment of the upper extremity（FMA-UE）,modified Ashworth（MAS）,modified Bathel index（MBI）and resting motion threshold（r MT）assessment before and after treatments.Among them,23 patients underwent f NIRS before and after treatment to detect changes in oxyhemoglobin concentration（Hb O₂）in 4 regions of interest（ROI）of the cerebral cortex.4 ROIs were bilateral premotor and supplementary motor cortex（PMC-SMA）and sensorimotor cortex（SMC）.Results:The FMA-UE and MBI scores were significantly higher in both groups after treatment（P<0.05）;the change in FMA-UE scores was significantly higher than in the control group（9.41±6.11 vs.4.06±2.73,P<0.05）;and FMA-UE scores were clinically significant in the experimental group（P<0.05）,the MAS grade of the flexor elbow muscle group was significantly lower,the△Hb O₂in the affected hemispheres of SMC area was significantly increased(（43.19±52.77）ⅹ10^-3vs.（73.89±36.81）ⅹ10^-3,P<0.05),and r MT of the unaffected hemispheres M1 was significantly higher than that of the control group（45.35±12.79 vs.36.71±11.00,P<0.05）.There was a significant positive correlation between the improvement in FMA-UE score and the increase of r MT in the unaffected hemispheres（r_s=0.622,P<0.001）,as well as the△Hb O₂in the affected hemispheres of SMC area（r_s=0.496,P<0.05）.There was no statistically significant difference in MAS grade of flexor elbow muscle,the r MT of the unaffected hemispheres and△Hb O₂in the affected hemispheres of SMC area within the control group（P>0.05）.The MAS grade distribution of elbow extension and wrist flexor muscles in both groups were not statistically significant in inter-and intra-group comparisons,as well as the△Hb O₂of bilateral hemispheres of PMC-SMA area and unaffected hemispheres of SMC area（P>0.05）.Conclusion:（1）Both low-frequency rTMS and low-frequency rTMS combined with rPMS can improve the upper limb motor function and daily living ability of recovering stroke patients.Low-frequency rTMS combined with rPMS improves upper limb motor function in stroke with better effect than low-frequency rTMS stimulation clinical significance.（2）The improvement of upper limb motor function in stroke by low-frequency rTMS combined with rPMS may be related to reduced unaffected hemispheres M1 excitability and increased hemodynamic activation in the SMC of the affected hemisphere.