| PTSD may cause physical and psychological impairment to individuals.Many core symptoms of patients with PTSD are directly or indirectly associated with cognitive impairment.Impaired memory suppression in cognitive function may be one of the causes of core PTSD symptoms and may play a more critical role in the onset and development of PTSD symptoms.Compared with pharmacotherapy and psychotherapy,TMS interventions can not only effectively improve PTSD symptoms,but also have the advantages of non-invasive,and relatively easy to implement.However,the treatment time of i TBS,which has been commonly used in clinical practice is so long that the patients’ coordination is poor.i TBS is a new stimulus mode,which has the advantages of shorter treatment time,faster onset and longer duration of the effect,but there is still a lack of research on its effect of the intervention of PTSD symptom.Hence,in this study,we used the PCL-C scale to screen out participants with PTSD symptoms,PTGI and TNT,the classical paradigm of memory suppression,to assess the symptoms and memory suppression ability of PTSD,and then explored the intervention effect of the new stimulation mode of i TBS on the core symptoms and memory suppression function of PTSD.The reseach of its neurophysiological mechanism were also performed through EEG technology.ContentsStudy 1: Characteristics of memory suppression function in post-traumatic stressStudy 2: The effect of transcranial magnetic stimulation with i TBS model on PTSD symptomsStudy 3: The effect of transcranial magnetic stimulation with i TBS model on memory suppression function in PTSD MethodsStudy 1: In this study,25 PTSD participants and 25 healthy participants were enrolled.The general information of the participants was surveyed using the demographic data questionnaire,the clinical symptoms of the participants were assessed using the PCL-C scale,the behavioral data on the memory suppression function of the participants was collected using the TNT paradigm,and the neurophysiological information of the participants was collected using the EEG device.Study 2: In this study,75 participants with PTSD symptoms were involved,who were randomly divided by random number table method into three groups: i TBS group,commonly used high-frequency r TMS group and sham stimulation group.TMS was given for fifteen days and once a day consecutively.TMS were performed with the pulsed magnetic field stimulator of M-series,produced by Yingzhi Company,Shenzhen.The DLPFC was selected as the site of stimulation and the clinical symptoms of the participants were assessed by scale before and after the intervention.Study 3: The grouping and intervention methods of participants in this study were consistent with Study 2.Data were collected using the TNT paradigm and EEG techniques before and after the intervention,and then the improvement of memory suppression function in PTSD paticipants of different intervention models were explored.ResultsStudy 1: The correct rate of PTSD group was significantly higher than that of healthy group under negative condition(p<0.01);the response time induced by negative stimulus was significantly longer than that induced by neutral stimulus;and the inhibitory conditioned response time was not significantly different between PTSD group and baseline(p=0.219);neutral stimulus evoked larger N2 amplitudes than negative stimulus in the PTSD group(p<0.01),under the inhibitory condition.Under the condition of inhibiting negative emotional stimulus,the control group induced larger N2 and P3 amplitudes than the PTSD group.Study 2: The scores of PCL-C in i TBS group and r TMS group were both significantly lower than those in sham stimulation group(p<0.01),and there was no significant difference between the two groups(p=0.973).The scores of PTGI in i TBS group and i TMS group were both significantly higher than those in sham stimulation group(p<0.01),there was no significant difference between the two groups on PCL-C and PTGI(p=0.732).Study 3: Behavioral Results: After the intervention of the three groups of participants,there was no significant difference in the main effect between the correct rates of different groups under the condition of neutral inhibition of the TNT task(p=1.025).The main effect of the intervention was significant,and the correct rate in the post-test was significantly greater than that in the pre-test(p<0.01).There was a significant interaction between grouping and pre-and post-test under the condition of negative inhibition,and there was a significant difference between the correct rates of i TBS group and r TMS group and the correct rate of sham stimulation group in post-test(p<0.431).There was no significant difference between the correct rates of the post-test and the pre-test in the sham stimulation group.There was no statistically significant difference in the main effect between the reaction times of different groups under the condition of neutral inhibition(p=0.128).The main effect difference before and after the intervention was statistically significant,and the reaction time of the post-test was significantly greater than that of the pre-test(p<0.01).The interaction between grouping and pre-and post-test was significant(p<0.01).Simple effect analysis was performed,and the results showed that the response time of i TBS group and r TMS group was significantly higher than that of sham stimulation group(p<0.01).ERP results: There was significant difference in the mean amplitudes of the N2 component before and after the three groups of participants(p<0.01).There was significant difference in the mean amplitudes of N2 between the i TBS group and the r TMS group and the sham stimulation group in the post-test(p <0.01),and there was no significant difference in the mean amplitudes of N2 between the i TBS group and the r TMS group(p=0.076).There was a statistically significant difference between the three groups of P3 amplitudes before and after the test(p<0.01).Compared with the control group,the i TBS group and the r TMS group participants showed a greater change in the mean P3 amplitudes in post-test,and there was no significant difference in the mean P3 amplitudes between the i TBS group and the r TMS group(p=0.052).ConclusionStudy 1: Compared with healthy participants,PTSD individuals not only have more perceptual processing and coding of negative stimulus,but also may have top-down suppression control defects.In the stage of memory retrieval suppression,although more cognitive resources will be invoked and greater cognitive effort will be exerted,it is still unable for them to successfully suppress the memory that needs to be suppressed.Study 2: Compared with sham stimulation,i TBS mode can effectively improve PTSD symptoms,and the degree of improvement is not significantly different from r TMS mode.Study 3: The results of behavioral index analysis showed that under the condition of negative stimulus,the i TBS mode had a more significant effect than the high-frequency r TMS mode group.The results of EEG analysis showed that both methods were effective in improving memory suppression ability,and i TBS mode was more effective in improving negative memory suppression ability. |
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