Neural differences underlying face processing in veterans with TBI and co-occurring TBI and PTSD.

Area of Science:

• Neuroscience
• Psychiatry
• Military Health

Background:

• Traumatic brain injury (TBI) is prevalent in military personnel, often co-occurring with posttraumatic stress disorder (PTSD).
• TBI affects neural networks involved in emotional processing, yet the neural correlates of emotional processing in TBI and PTSD/TBI are understudied.
• Understanding these neural alterations is crucial for elucidating comorbidity mechanisms.

Purpose of the Study:

• To investigate the neural correlates of emotional processing in military personnel with TBI and comorbid PTSD/TBI.
• To compare brain activation and functional connectivity during emotional face processing across control, TBI, and PTSD/TBI groups.
• To identify how TBI and PTSD/TBI impact neural activity related to affective processing.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to assess brain activity and functional connectivity.
• Participants included military controls, individuals with a history of TBI, and individuals with both TBI and PTSD (N=53).
• Emotional face processing tasks were administered during fMRI scans, with whole-brain activation and seed-based connectivity analyzed.

Main Results:

• The TBI group exhibited hypoactivation in certain areas during face versus shape processing compared to other groups.
• The PTSD/TBI group showed increased functional connectivity between the amygdala and insula, and with prefrontal and posterior cingulate regions.
• Few significant whole-brain differences were found in direct pairwise comparisons, highlighting subtle but important connectivity changes.

Conclusions:

• TBI alone was linked to reduced activation during emotional face processing.
• PTSD with TBI was associated with altered functional connectivity, particularly involving the amygdala, insula, and prefrontal/cingulate areas.
• Individuals with PTSD/TBI may require enhanced frontal-insula connectivity for effective emotional processing, suggesting potential therapeutic targets.