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Recurrent PTSD, traumatic brain injury associated with similar weakened brain connectivity

Analysis of MRI data indicated a relationship between re-experiencing PTSD symptoms and weakened connectivity in a brain network involved in providing contextual information, and a similar relationship was observed in veterans who experienced mild traumatic brain injury.

“The psychological and physical consequences of trauma can be devastating to affected individuals and their families. U.S. veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn experience particularly high rates of trauma-related conditions, such as [PTSD] and traumatic brain injury,” Jeffrey M. Spielberg, PhD, of the Veteran Affairs Boston Healthcare System, and colleagues wrote. “Understanding the neural causes and consequences of these conditions has been labeled a high research priority, owing to the high rates of disability and suicide associated with trauma.”

To assess functional brain networks and topological properties related to current PTSD severity and mild traumatic brain injury (TBI), researchers evaluated resting-state functional MRI data from 208 veterans of Operation Enduring Freedom, Operation Iraqi Freedom and Operation New Dawn, all of whom experienced a traumatic event and qualified for PTSD criterion A.

Analysis identified two brain networks in which weaker connectivity was linked to higher PTSD re-experiencing symptoms. One of the networks was identified only among veterans with comorbid mild TBI.

Re-experiencing symptoms was associated with worse functional segregation, which is necessary for specialized processing, and lower influence of key regions in the brain network, including the hippocampus.

“We demonstrate in a large sample of veterans that trauma-related pathology has important and heterogeneous effects on brain networks and related graph theoretic topological properties. These results move us closer to understanding the precise networks disturbed by trauma and highlight the importance of taking into account the interactive effects of different manifestations of trauma pathology,” the researchers concluded. – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.