Proton magnetic resonance spectroscopy revealed differences in the glutamate + glutamine/creatine ratio of the anterior cingulate cortex between healthy and pediatric post-traumatic stress disorder patients diagnosed after 2008 Wenchuan earthquake Aims: Earthquakes always leave many surviving teenagers suffering from various mental problems, such as post-traumatic stress disorder (PTSD). We studied the metabolites in current and remitted pediatric PTSD patients and healthy controls after an earthquake, aiming to find the neurochemistry differences in these teenagers.Methods: Proton magnetic resonance spectroscopy ( 1 H-MRS) was performed in the anterior cingulate cortex (ACC) of 21 healthy, 10 PTSD and 23 remitted subjects.Results: Significantly lower glutamate + glutamine/ creatine (Glx/Cr) levels in the ACC (1.15 ± 0.14 vs 1.37 ± 0.08, P = 0.047) were found in PTSD subjects relative to remitted subjects; and significantly lower Glx/Cr levels in the ACC (1.37 ± 0.08 vs 1.59 ± 0.10, P = 0.045) were found in remitted subjects relative to healthy controls. Conclusions:Our findings imply that the Glx/Cr ratio in the ACC can be used to differentiate not only between healthy and pediatric PTSD patients, but also between the current and remitted phases of pediatric PTSD. The changes in the Glx/Cr ratio may be caused by brain dysfunction in the current phase and recovery in the remitted phase.

Neuroimaging studies in children and adolescents with post-traumatic stress disorder (PTSD) have focused on abnormal structures and the functionality of a few individual brain regions. However, little is known about alterations to the topological organization of whole-brain functional networks in children and adolescents with PTSD. To this end, we investigated the topological properties of brain functional networks derived from resting-state functional magnetic resonance imaging (r-fMRI) in patients suffering from PTSD. The r-fMRI data were obtained from 10 PTSD patients and 16 trauma-exposed non-PTSD subjects. Graph theory analysis was used to investigate the topological properties of the two groups, and group comparisons of topological metrics were performed using nonparametric permutation tests. Both the PTSD and non-PTSD groups showed the functional brain network to have a small-world architecture. However, the PTSD group exhibited alterations in global properties characterized by higher global efficiency, lower clustering coefficient, and characteristic path length, implying a shift toward randomization of the networks. The PTSD group also showed increased nodal centralities, predominately in the left middle frontal gyrus, caudate nucleus, and hippocampus, and decreased nodal centralities in the left anterior cingulate cortex, left paracentral lobule, and bilateral thalami. In addition, the clustering coefficient and nodal betweenness of the left paracentral lobule were found to be negatively and positively correlated with the re-experiencing and hyper-arousal symptoms of PTSD respectively. The findings of disrupted topological properties of functional brain networks may help to better understand the pathophysiological mechanism of PTSD in children and adolescents.

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Background: Most youths who suffer from posttraumatic stress disorder (PTSD) lose their diagnosis in the first 1-2 years. However, there are few studies on this brain mechanism, and the heterogeneity of the findings is partially due to the different stimuli applied and the mixed trauma history. Therefore, the use of trauma-related/unrelated stimuli to study the remittance mechanism of earthquake-induced PTSD could advance our knowledge of PTSD and inspire future treatment.Methods: Thirteen youths with PTSD, 18 remitted participants and 18 control participants underwent functional magnetic resonance imaging (fMRI) while viewing trauma-related pictures, trauma-unrelated negative pictures and scrambled pictures.Results: Under trauma-unrelated condition, the neural activity of the left hippocampus in the remitted group was in the middle between the two other groups. Under trauma-related condition, the PTSD and the remitted group exhibited higher neural activity in the right middle occipital gyrus than controls. The remitted group showed higher neural activity in the right parahippocampal gyrus and right lingual gyrus under trauma-related condition than trauma-unrelated condition, while no significant difference was found in PTSD group.Conclusion: PTSD symptom-related group difference is mainly reflected in the left hippocampus under the trauma-unrelated condition, while the hyperactivity in the right middle occipital gyrus under trauma related condition could be an endophenotype for PTSD.