A new neuroimaging study shows a link between childhood post-traumatic stress disorder (PTSD) and a disruption in the structure of brain networks. The findings, published in the the journal Radiology, could one dayhelp lead to the development of new treatments for PTSD.
Children are particularly vulnerable to the effects of PTSD. Research has shown that childhood trauma is tied to a variety of neurochemical and hormonal effects that can lead to lasting changes in brain structure and function.
Brain studies with magnetic resonance imaging (MRI) may be used to identify vulnerable patients, allowing interventions to begin sooner, potentially preventing any negative brain changes.
For the study, researchers from China used MRI to compare the brain structures of 24 children with PTSD to a control group of 23 trauma-exposed children without PTSD. The children had experienced the 2008 Sichuan earthquake, a massive disaster in south central China that killed almost 70,000 people and injured more than 370,000.
Diffusion tensor imaging (DTI), an MRI technique that reveals the integrity of the brain’s white matter, was used to evaluate the brain’s connectome — the map of the neural connections in the brain.
The human connectome includes a series of nodes, or brain regions, linked by connections known as edges. Nodes with a relatively high number of edges are referred to as hubs.
“Generally speaking, the structural connectome and the functional connectome are based on different types of raw images, which may be used to investigate the brain’s abnormalities through different views,” said study lead author Qiyong Gong, M.D., Ph.D., from West China Hospital of Sichuan University in Chengdu, China.
The findings revealed significant structural differences between the PTSD and non-PTSD groups. The brains of children with PTSD showed changes suggestive of reduced network efficiency due to damage or disconnection between linked regions.
The study also showed a concerning trend in the structural connectome of PTSD patients. Typically, the brain operates partly as a small-world network in which most nodes can be reached from every other node by only a few steps. A small-world network contributes to the high-efficiency transfer of information between networks.
However, in the brains of PTSD patients, the structural connectome was leaning more toward regularization, a phenomenon in which the neural network moves from a small-world to a more regular network. A regular network is more localized, so it takes many more steps to reach distant nodes.
“In a previous functional and current structural connectome study of the same patient group, we found a shift toward regularization in the brain networks of the PTSD patients relative to controls,” said Gong. “Thus, we speculate that this regularization process may be a general pattern of pediatric PTSD.”
Differences were also discovered in the salience network, a group of brain regions that select which stimuli are deserving of attention. The finding could point to a potential target for future treatment plans in pediatric PTSD.
“These abnormalities suggest that PTSD can be better understood by examining the dysfunction of large-scale spatially distributed neural networks,” said Gong.
The researchers hope to conduct follow-up imaging on at least some of the patients in the study to further study brain changes tied to PTSD.