Effects Of Repetitive Transcranial Magnetic Stimulation On Resting-State Functional Connectivity Characteristics In Smoking Addicts

Background: Smoking is one of the most prevalent and persistent addictions in history.At present,the intervention strategies for smoking addiction are mainly divided into three types: physical therapy,psychotherapy,and drug therapy.One of the mainstream methods in the treatment of addiction is transcranial magnetic stimulation(TMS);TMS shows potential for treating nicotine addiction due to its ability to noninvasively modulate brain activation.Secondly,based on previous studies and the experience of clinical cases,numerous studies on addiction showed that repetitive transcranial magnetic stimulation(RTMS)on the dorsolateral prefrontal cortex(DLPFC)plays a key role in reward circuitry and impulse inhibition,which is a common brain area in the treatment of substance addiction.Ultimately,we consider RTMS on the DLPFC as our primary treatment for smoking addiction.Method: In this study,a total of 59 smokers,including 41 RTMS group with ASD and 18 group,were treated for one week(40 sessions of 10 Hz high-frequency RTMS stimulation of the dorsolateral prefrontal cortex(DLPFC)).The Fagerstrom Nicotine Dependence Test(FTND)score,the brief questionnaire of smoking urges(QSU-B),functional connectivity(FC)and effective connectivity(EC)of chronic smokers were analyzed in resting state.Results: In terms of FTND and QSU-B scores,both the RTMS group and the Sham group reduced the degree of nicotine dependence after one week of treatment,but did not reach statistical significance.In the resting-state data analysis,firstly,we found that the RTMS group which after treatment had significantly higher functional connectivity(FC)in the left DLPFC-paralimbic(including the left rectus gyrus,left anterior cingulate gyrus,and left parahippocampal gyrus),DLPFC-Association(including the left fusiform gyrus,left superior parietal gyrus,and right inferior parietal gyrus),Subcortical(including the left caudate nucleus,the left anterior cingulate gyrus,and the left parahippocampal gyrus)and DLPFC-cerebellum,respectively,than the RTMS group which before treatment and the Sham group which after treatment.Secondly,we found that the effective connectivity of the left DLPFC to the Association(including the right fusiform gyrus,left lingual gyrus,left inferior occipital gyrus,and right superior limbic gyrus),Primary sensory(including the right postcentral gyrus and left precentral gyrus),Paralimbic(including the left insula)and cerebellum,respectively,was significantly higher than that RTMS group which before treatment and Sham group which after treatment.Finally,we found that the effective connectivity from the right suboccipital to the left DLPFC was significantly higher in the RTMS group than in the RTMS group and Sham group after treatment.Conclusion: The mechanism of RTMS on nicotine dependence and smoking impulsivity may be to reduce or inhibit the role of the reward system on the motivation and use of smoking.At the same time,RTMS on the left DLPFC can enhance the inhibitory control of driving-reward related brain areas in patients with tobacco addiction.The enhanced effective connectivity suggests that the left DLPFC activity may have a causal effect on the reward system in reducing smoking craving.The present study also provides evidence for this process mechanism of RTMS in the treatment of smoking addiction.