Abstract:  Objective To evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on motor function and serum levels of matrix metalloproteinase-9 (MMP-9)/high-sensitivity C-reactive protein (hs-CRP) in patients with ischemic stroke (IS). Methods A total of 54 patients met the inclusion criteria were randomly divided into low-frequency stimulation group, high-frequency stimulation group and sham stimulation group with 18 in each group. All the patients were given routine medical treatment and rehabilitation training. Then the 0.5 Hz rTMS treatment was performed on the healthy side in the primary motor cortex (M1) of the low-frequency stimulation group, and the 10 Hz rTMS treatment was performed on the affected side of the high-frequency stimulation group. It was worth noting that the sham stimulation was also performed on the affected side of the M1 area, but no current, only sound, and the treatment lasted 3 weeks, 5 d per week. Finally, serum levels of MMP-9 and hs-CRP were measured by enzyme-linked immunosorbent assay (ELISA) at 3 days before treatment and 3 weeks after treatment, and the simple motor function on the affected side was evaluated by the FMA scale, meanwhile, the motor evoked potential (MEP) latency and central motor conduction time (CMCT) were recorded. The motor function and serum expression levels of MMP-9 and hs-CRP were compared before and after treatment between the three groups. Results There were no significant differences in serum concentrations of MMP-9 and hs-CRP, FMA scores, MEP latency and CMCT before treatment between the three groups (P＞0.05). After 3 weeks of treatment, the serum concentration of MMP-9 and hs-CRP were lower in low frequency stimulation and high frequency stimulation groups than those of the sham-stimulated group, and the FMA scores of the upper and lower limbs were higher than those of the sham- stimulated group, and the MEP latency/CMCT were shorter than those of sham-stimulated group. There were no significant differences in above indicators between low frequency stimulation and high frequency stimulation groups (P＜0.05). After 3 weeks of treatment, the serum concentrations of MMP-9 and hs-CRP were negatively correlated with the corresponding upper and lower FMA scores in the rTMS treatment group (low and high frequency groups, P＜0.01). Conclusion rTMS can accelerate the recovery of motor function in patients with IS, which may be related to the down-regulation of serum expression levels of MMP-9 and hs-CRP.

Key words:  transcranial magnetic stimulation, stroke, matrix metalloproteinase 9, hypersensitive C-reactive protein, motor function