White matter integrity alterations in post-traumatic stress disorder

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Post-traumatic stress disorder (PTSD) is a severe condition following trauma exposure.
• Previous research indicated reduced gray matter (GM) in PTSD patients.
• This study investigates white matter (WM) integrity in brain networks related to PTSD.

Purpose of the Study:

• To examine microstructural integrity of WM tracts connecting frontal/subcortical brain regions in adults with and without PTSD.
• To correlate WM integrity with clinical severity of PTSD symptoms.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess WM integrity via fractional anisotropy (FA).
• Seventy-five adults were studied: 25 with PTSD, 25 trauma-exposed controls, and 25 healthy controls.
• Clinical assessments included the Clinician Administered PTSD Scale (CAPS).

Main Results:

• Trauma-exposed individuals, with or without PTSD, showed reduced FA in the uncinate fasciculus (UF), cingulum cingulate gyrus (CCG), and corpus callosum (CC) compared to healthy controls.
• Lower FA in the right UF, CCG, CC body, and right superior longitudinal fasciculus (SLF) correlated with higher lifetime PTSD symptom severity.
• Reduced FA in UF and SLF was negatively correlated with gray matter volume in the rostral anterior cingulate cortex (ACC) in PTSD subjects.

Conclusions:

• Compromised WM integrity in tracts connecting the amygdala to the ACC (UF, CCG) may contribute to fear processing deficits in PTSD.
• These findings highlight the role of white matter microstructure in the pathophysiology of PTSD.
• DTI provides valuable insights into the neural underpinnings of PTSD.