Effect Of Low-frequency Repetitive Transcranial Magnetic Stimulation Plus Occupational Therapy On Motor Cortex Plasticity In Healthy Volunteers

Objective: To investigate the effect of low-frequency repetitive transcranial magnetic stimulation(r TMS) combined with occupational therapy on hand motor cortex plasticity in healthy volunteers. And further analyze the feasibility and topological direction of neuroplasticity of hand motor cortex.Methods: ?Ten right-handed healthy volunteers were enrolled in this study. None of the subjects had contraindications for magnetic resonance imaging and transcranial magnetic stimulation. The subjects were adequately informed about purposes, procedures and risks of the study, then they signed an informed written consent. ?Nine hole peg test was chosen to evaluate finger dexterity of both hands. And each person underwent cortical brain mapping via both functional magnetic resonance imaging(f MRI) and navigated transcranial magnetic stimulation(n TMS) before the treatment.? Ten volunteers received 15-min low-frequency r TMS over the dominant hemisphere. r TMS parameters are 1Hz, 90% resting motor threshold, totally 900 pulses/d. After r TMS every participate was obliged to accomplish 1h occupational therapy. The whole exercise last 2 weeks. ?After the process, nine hole peg test?f MRI and n TMS were done again just like before. Data of motor function and hand motor cortex at admission and discharge were compared by SPSS.Result: All participants receiving treatment finished the study. No serious adverse events were reported. A significant correlation between motor dexterity and number of activated voxels in f MRI(r=-0.73,p<0.05). A significant correlation between motor dexterity and mapping of hand motor cortex in f MRI(r=-0.78,p<0.05). Compared with baseline datum, the change of score of nine hole peg test for left hand dexterity decreased significantly(p<0.05), while right hand had no statistical differences(p>0.05). After intervention, the number of activated voxels in f MRI significantly increased in right motor cortex, especially in Brodmann 6(p<0.05); But the mapping of both hands using n TMS was not significantly changed because of intervention(p>0.05).Conclusion: TMS was identified as a safe, useful and non-invasive options for clinical therapy. Low-frequency repetitive transcranial magnetic stimulation combined with occupational therapy can be used as a effective method for neuroplasticity. The result of functional magnetic resonance imaging indicated that functional cortical reorganization can be induced artificially. But the mapping of n TMS had no difference, maybe connected with the time or intensity of tasks.