Influence of Mild Traumatic Brain Injury (TBI) and Posttraumatic Stress Disorder (PTSD) on Pain Intensity Levels in OEF/OIF/OND Veterans.

OBJECTIVE: Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are common among US veterans of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND). We postulated that these injuries may modulate pain processing in these individuals and affect their subjective pain levels.

DESIGN: Cross-sectional.

SUBJECTS: 310 deployed service members of OEF/OIF/OND without a lifetime history of moderate or severe TBI were included in this study.

METHODS: All participants completed a comprehensive evaluation for Blast Exposure, mTBI, PTSD, and Pain Levels. The Boston Assessment of TBI-Lifetime Version (BAT-L) was used to assess blast exposure and potential brain injury during military service. The Clinician-Administered PTSD Scale (CAPS) characterized presence and severity of PTSD. The Visual Analog Scale (VAS) was used to assess pain intensity over the previous month before the interview, with higher scores indicative of worse pain. Statistical analysis was performed by ANOVA and results were adjusted for co-morbidities, clinical characteristics and demographic data.

RESULTS: In comparison to control participants (veterans without mTBI or current PTSD), veterans with both current PTSD and mTBI reported the highest pain intensity levels, followed by veterans with PTSD only (P < 0.0001 and P = 0.0005, respectively). Pain levels in veterans with mTBI only were comparable to control participants.

CONCLUSIONS: Comorbid PTSD and mTBI is associated with increased self-reported pain intensity. mTBI alone was not associated with increased pain.