MRI Research On The Effects Of The Cause Of Death Of An Only Child On Brain Structure And Function In Parents With Post-Traumatic Stress Disorder

Part One: MRI research on the effects of the cause of death of an only child on cortical thickness in parents with or without post-traumatic stress disorderObjective: To investigate the effects and significance of the cause of death of an only child on brain cortical thickness in parents with or without post-traumatic stress disorder(PTSD).Methods: The study enrolled a total of 143 parents who lost their only child,including 86 parents(11 with PTSD and 75 without PTSD)whose children died of unnatural or artificial factors(violent death group,VD group)and 57 parents(13 with PTSD and 44 without PTSD)whose children died of natural or internal factors of the human body(nonviolent death group,NVD group).The Clinical Administered PTSD Scale(CAPS)was used to evaluate the severity of the subjects’ clinical symptoms.3D-T1 magnetic resonance imaging data of all subjects were collected and values of cortical thickness were calculated by Free Surfer 6.0 software.SPSS 22.0 software was used for statistical analysis of clinical characteristics.Two-way analysis of covariance was performed to examine changes in cortical thickness on these parents.Spearman’s correlation analyses between the cortical thickness of significant regions and the scores of CAPS were utilized.Results: Significant main effects of causes of death were found in the right frontal pole and right precuneus.A post-hoc analysis showed that the VD group had higher cortical thickness in these regions than the NVD group.No significant main effect of PTSD diagnosis was observed.Additionally,there was no interaction between the causes of death and the diagnosis of PTSD.Moreover,the cortical thickness of the right precuneus was negatively correlated with B2(trauma-related dreams)score in CAPS in the NVD group(r=-0.383,P=0.003).Conclusion: There were differences in the cortical thickness of local structure of the default mode network between parents whose only child died of various causes regardless of PTSD diagnosis,and there was a certain correlation with the clinical symptom of trauma-related dreams.Our study suggests that the causes of the only child’s death may be unique factors affecting bereaved parents’ neural health.Part Two: MRI research on the effects of the cause of death of an only child on degree centrality in parents with post-traumatic stress disorderObjective: To investigate the effects and significance of the cause of death of an only child on brain degree centrality(DC)in parents with post-traumatic stress disorder(PTSD).Methods: The study enrolled a total of 51 parents with PTSD,including 35 PTSD parents whose children died in emergencies(acute shidu PTSD group)and 16 PTSD parents whose children died of chronic causes such as diseases(chronic shidu PTSD group).50 local adults were also included as healthy control group.The Clinical Administered PTSD Scale(CAPS)was used to evaluate the severity of the subjects’ clinical symptoms.Resting-state functional magnetic resonance imaging data of all subjects were collected and values of DC were calculated by DPARSF software.SPSS 22.0 software was used for statistical analysis of clinical characteristics.One-way analysis of covariance was performed among three groups,while post hoc was performed between any two groups.What’s more,partial correlation analyses were utilized between the DC values of abnormal brain regions and the scores of CAPS,with age,gender and years of education as covariates.Results: Significant group effects were found in multiple regions: the right inferior temporal gyrus,the right temporal pole,the right orbital inferior frontal gyrus,bilateral medial superior frontal gyri,the left inferior parietal angular gyrus and the left postcentral gyrus.Compared with healthy control group,the DC of two patients group increased in the right inferior temporal gyrus;the DC of acute shidu PTSD group decreased in the right temporal pole and the right orbital inferior frontal gyrus;the DC of chronic shidu PTSD group decreased in the left inferior parietal angular gyrus and the left postcentral gyrus.Compared with chronic shidu PTSD group,the DC of acute shidu PTSD group increased in the left inferior parietal angular gyrus and the left postcentral gyrus,and decreased in the right temporal pole,the right orbital inferior frontal gyrus and bilateral medial superior frontal gyri.In the chronic shidu PTSD group,the DC of the left postcentral gyrus was negatively correlated with C1(avoid trauma-related thoughts and feelings)score in CAPS(r=-0.606,P=0.028).In the acute shidu PTSD group,the DC of the left medial superior frontal gyrus was negatively correlated with D4(high vigilance)score(r=-0.416,P=0.020).Conclusion: There exist functional abnormalities of multiple brain regions in parents with PTSD whose only child died of various causes.The more serious high arousal symptoms of the acute shidu parents may be related to the abnormalities of prefrontal-amygdala neural circuit;while the chronic shidu parents show higher avoidance which may be associated with the dysfunction of somatosensory brain regions such as postcentral gyrus.