Disrupted brain circuitry links TBI to depression in military

Disruptions in the circuitry of cognitive emotional pathways in the brain may explain depression symptoms among service members who experienced mild traumatic brain injury, according to data presented at the Radiological Society of North America annual meeting.

“With the increased survival of soldiers due to improvements in body armor and advanced medical care, there has been an increase in the number of soldiers surviving major trauma. Consequently, a large number of soldiers are returning from war with mild TBI,” study researcher Ping-Hong Yeh, PhD, of Walter Reed National Military Medical Center, Bethesda, Maryland, said in a press release. “Mood disorders are very common in military-related mild TBI patients. This is an ongoing problem facing a large number of warriors in current areas of conflict, and it is likely to be a persistent problem for the foreseeable future."

To identify associations between brain microstructural changes and network connectivity in military members with mild TBI, researchers conducted structural MRI, diffusion-weighted imaging and resting state functional MRI among 130 active service members diagnosed with mild TBI and 53 controls without TBI. Study participants had mean ages of 34.7 years and 31.9 years.

Overall, 75 participants with mild TBI had moderate-to-severe depression symptoms.

Participants with moderate-to-severe depression and mild TBI exhibited decreased functional connectivity within the anterior default mode network and executive control network and increased thalamo-striatal connectivity, compared with participants without TBI and those with mild depression and mild TBI.

These findings suggest that decreased default mode network suppression and increased rumination are symptomatic of depression with mild TBI, according to researchers.

“We found consistencies in the locations of disrupted neurocircuitry as revealed by [diffusion-weighted imaging] and resting-state functional MRI that are unique to the clinical symptoms of mild TBI patients. We have related the brain structural and functional changes in cognitive-emotional networks to depressive symptoms in mild TBI patients,” Yeh said in the release. “Though the results of this study were not applied directly to patient care, the neuroimaging changes we found might be incorporated into treatment plans for personalized medicine in the future.” – by Amanda Oldt

Reference:

Yeh P-H, et al. Aberrant brain networks efficiency in mild traumatic brain injury patients with depression symptom — A multimodal study. Presented at: Radiological Society of North America Annual Meeting; Nov. 26-Dec. 1, 2016; Chicago.

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