Mild Traumatic Brain Injury and Career Stage Associate with Visible Perivascular Spaces in Special Operations Forces...

Area of Science:

• Neuroscience
• Radiology
• Military Medicine

Background:

• Mild traumatic brain injury (mTBI) and blast exposure in military personnel can impair brain waste clearance, increasing neurological disease risk.
• Perivascular spaces (PVS) are crucial for the glymphatic system's waste clearance function, particularly during sleep.
• Enlarged PVS are observed in neurodegenerative diseases and animal models of neurotrauma.

Purpose of the Study:

• To investigate the association between PVS morphology, mTBI history, and military career stage in Special Operations Forces (SOF) Soldiers.
• To quantify PVS characteristics in relation to mTBI and occupational exposures.

Main Methods:

• T2-weighted neuroimaging was used to acquire 3D whole-brain volumes in 223 SOF combat Soldiers.
• A deep convolutional neural network was employed for PVS segmentation within white matter.
• Non-parametric Mann-Whitney U tests analyzed PVS number and volume differences between groups.

Main Results:

• Soldiers with a history of mTBI exhibited significantly greater PVS number and volume compared to those without mTBI history.
• In-career SOF Soldiers showed increased PVS number and volume relative to a baseline cohort.
• These findings were observed in clinically recovered Soldiers, suggesting persistent physiological changes.

Conclusions:

• mTBI history is linked to increased PVS burden in SOF combat Soldiers, even after clinical recovery.
• Elevated PVS may signify impaired glymphatic system function and potential increased risk for neurological diseases.
• Further research is needed to explore PVS as a neurobiological outcome and the impact of interventions like sleep optimization.