Cavum Septum Pellucidum Enlargement in Special Operations Forces Members Is Associated with Lifetime Exposure to...

Area of Science:

• Neuroimaging
• Military Medicine
• Traumatic Brain Injury

Background:

• Cavum septum pellucidum (CSP) is a common neuroimaging finding, often associated with repetitive head trauma.
• The relationship between blast exposure and CSP in military personnel, particularly Special Operations Forces (SOF), is not well understood.

Purpose of the Study:

• To investigate the association between lifetime blast exposure and CSP morphology in SOF personnel.
• To determine if specific types of blast exposure correlate with CSP characteristics.

Main Methods:

• Retrospective analysis of 323 SOF members who underwent high-resolution 3T MRI and completed the Blast Exposure Threshold Survey (BETS).
• CSP grade and length were assessed, and a CSP length-to-septum length ratio was calculated.
• Statistical analyses included variance inflation factor, LASSO regression, group comparisons, and multivariable regression models, focusing on log-transformed blast exposure counts (log-BEC1-5).

Main Results:

• Lifetime exposure to large explosives (log-BEC5) was the only significant predictor of CSP measures.
• SOF members with BEC5 exposure showed significantly higher CSP presence (42.1% vs. 22.0%) and longer CSP length (median 3 mm vs. 2 mm).
• Increased log-BEC5 was associated with greater odds of CSP presence and increased CSP length and CSP ratio in adjusted models.

Conclusions:

• Cumulative exposure to heavy explosives is significantly associated with CSP enlargement in SOF personnel.
• CSP may serve as a potential neuroimaging biomarker for blast-related neurotrauma in military populations.
• Further research is warranted to explore the clinical implications of these findings.