Effects Of Transcranial Temporal Interference Stimulation On Brain Motor-network

Background:Transcranial Temporal Interference Stimulation(tTIS)is a new type of transcranial electrical stimulation(t ES),which combines the non-invasive and safe features of traditional t ES with the advantages of Deep Brain Stimulation(DBS)for precise stimulation of deep brain regions,bringing a new direction for future research and application of neuromodulation.Previous studies have demonstrated that t ES can modulate the cerebral cortex by applying low-intensity currents of different characteristics to target brain regions,thereby improving human motor and cognitive abilities and behavioral performance,but whether tTIS can modulate neural activity still needs to be verified in human experiments.In this study,resting-state functional magnetic resonance imaging(rsf MRI)was used to observe the effects of tTIS stimulation of primary motor cortex on motor networks.Method:A double-blind,randomized design was used for this study.Subjects were 21 healthy adults,and each subject required two visits,each receiving either tTIS or sham stimulation.The duration of the intervention was 20 min,with a peak tTIS current of 2m A,a carrier wave of 5000 Hz,and a random change of the envelope wave every 30 s within 5/10/20/40 Hz;the sham stimulation was unenergized throughout.Subjects’ rsf MRI data were acquired before,during and after the stimulation intervention.The analysis methods were the seed-based functional connectivity method and the independent component analysis-based functional connectivity method.Significant level values for individual voxel were set at P < 0.001,and cluster with a significant level of P < 0.05 were considered to be statistically significantly different.Results:Online: 1)Functional connectivity results based on independent component analysis.There was a significant stimulus time*stimulus type interaction,with tTIS eliciting a significant facilitative intervention effect in parts of the left prefrontal relative to the sham condition;no stimulus type main effect,no stimulus time main effect;parts of the left inferior prefrontal gyrus were significantly activated in the tTIS condition.2)Seed-based functional connectivity results: No interaction effect;presence of stimulus time main effect,activation results were shown in the left precentral gyrus and postcentral gyrus;activation results of stimulus type main effect were shown in the left middle temporal pole,superior temporal gyrus.Offline: only in the seed-based analysis method,there was a temporal main effect with activation in the right precentral and postcentral gyrus;no significant difference in the rest of the conditions Conclusion:Stimulation of the left primary motor cortex by tTIS significantly increased t the strength of functional connections between the motor network and the left prefrontal brain region.