Longitudinal MRI Study Of Brain Structural Changes In Parents Who Lost Their Only Child

Part I:A longitudinal MRI study of changes in cortical thickness and surface area in parents who lost their only childObjective To investigate the cross-sectional and longitudinal changes of brain cortical thickness and surface area in parents without psychiatric disorders who lost their only child,and to explore their relationship with various psychiatric symptoms.Methods The study enrolled 50 parents without psychiatric disorders who lost their only child（trauma-exposed non-psychiatric disorders,TENP group）and 40 well-matched healthy controls（HC group）.3D-T₁magnetic resonance imaging scans was performed on each participant at baseline and at follow-up.The psychologic status was assessed using Clinician-Administered PTSD Scale（CAPS）,the Hamilton Anxiety Rating Scale（HAMA）and the Hamilton Depression Rating Scale（HAMD）.Differences in brain structural phenotypes（cortical thickness,surface area,and their annual rate of change）between the TENP and HC groups were compared using Free Surfer software.Correlations between significant brain structural phenotypes and scores of various psychiatric symptoms in the TENP group were evaluated using multiple linear regressions.Results The TENP group showed a smaller surface area in the left inferior parietal gyrus than the HC group at baseline and follow-up（Baseline:P=0.003;Follow-up:P=0.014）.The TENP group showed slower rates of cortical thinning and surface area loss in several brain regions than the HC group from baseline to follow-up（all P<?0.05）.Moreover,slower rates of cortical thinning in the left insula,superior frontal gyrus,and superior temporal gyrus were associated with greater reductions in avoidance（r=0.431,P=0.002）,depression（r=0.637,P<0.001）,and trauma re-experiencing（r=0.468,P=0.005）symptoms scores over time in the TENP group,respectively.Conclusions The structural abnormalities that the trauma of losing an only child caused in the inferior parietal cortex may persist over time and be independent of the severity of psychiatric symptoms.The expansion of prefrontal,temporal,and insular regions implicated in emotional regulation may contribute to improvements in psychiatric symptoms in parents who lost their only child.Part II: A longitudinal MRI study of changes in white matter microstructural integrity in parents who lost their only childObjective To investigate the cross-sectional and longitudinal changes of white matter microstructure in parents without psychiatric disorders who lost their only child,and to explore their relationship with various psychiatric symptoms.Methods The study enrolled 38 parents without psychiatric disorders who lost their only child（trauma-exposed non-psychiatric disorders,TENP group）and 35 well-matched healthy controls（HC group）.Diffusion tensor imaging scans was performed on each participant at baseline and at follow-up.The psychologic status was assessed using Clinician-Administered PTSD Scale（CAPS）,the Hamilton Anxiety Rating Scale（HAMA）and the Hamilton Depression Rating Scale（HAMD）.Brain regions with significant differences in fractional anisotropy（FA）values between the TENP and HC groups at baseline were investigated by using Tract-based spatial statistics（TBSS）method,and the brain regions with significant differences were further used as the regions of interest for longitudinal follow?up analysis of the two groups.The relationship between FA values in significant brain regions and various psychiatric symptoms scores were evaluated using partial correlation analysis,with gender,age and years of education at baseline as covariates.Results Compared with the HC group,FA values of the bilateral anterior thalamic radiation（Left: P=0.021;Right: P=0.008）,corticospinal tract（Left: P<0.001;Right:P=0.002）,inferior fronto-occipital fasciculus（Left: P=0.001;Right: P=0.001）,superior longitudinal fasciculus（Left: P=0.002;Right: P=0.002）,left inferior longitudinal fasciculus（P<0.001）,uncinate fasciculus（P=0.023）,right cingulate gyrus（P=0.021）,cingulum（hippocampus）（P=0.001）,forceps major（P<0.001）and forceps major（P<0.001）in the TENP group were decreased at baseline.There was a negative correlation between the FA value of the left uncinate fasciculus and depression symptom score in the TENP group（r=-0.444,P=0.008）.From baseline to follow up,FA values of the right corticospinal tract P<0.001)and right superior longitudinal fasciculus（P=0.019）were decreased in the TENP group;The decrease of FA values of the right superior longitudinal fasciculus were negatively correlated with the decrease of trauma re-experiencing（r=-0.413,P=0.014）,hyperarousal（r=-0.357,P=0.035）,and depression（r=-0.360,P=0.034）symptoms scores in the TENP group.Conclusions The trauma of losing an only child can result in impaired microstructural integrity of white matter.As the post traumatic time goes by,parents who have lost an only child do not develop to PTSD and other psychiatric disorders,and the clinical symptoms are alleviated,the damage of the white matter microstructure continued to progress.