Combat exposure is associated with cortical thickness in Veterans with a history of chronic pain.

Chronic Pain (CP) has been associated with changes in gray matter integrity in the cingulate and insular cortex. However, these changes have not been studied in Veterans, despite high prevalence rates of CP and interactions with combat-derived disorders. In the current study, 54 Veterans with a history of CP and 103 Veterans without CP were recruited from the Translational Research Center for Traumatic Brain Injury and Stress Disorders (TRACTS). Cortical thickness from structural MRI scans was determined using the FreeSurfer software package. Results showed that Veterans with CP showed a negative association between cortical thickness and levels of combat exposure in the left inferior frontal gyrus and superior parietal cortex, as well as the right rostral middle frontal gyrus, precentral and postcentral gyri and the superior temporal cortex. These findings suggest that CP may alter the relationship between cortical thickness and exposure to the stress of combat.

Sleep Quality and Reexperiencing Symptoms of PTSD Are Associated With Current Pain in U.S. OEF/OIF/OND Veterans With and Without mTBIs.

Pain, a debilitating condition, is frequently reported by U.S. veterans returning from Afghanistan and Iraq. This study investigated how commonly reported clinical factors were associated with pain and whether these associations differed for individuals with a history of chronic pain. From the Boston metropolitan area, 171 veterans enrolled in the Veterans Affairs Center of Excellence were assessed for current posttraumatic stress disorder (PTSD) symptom severity, current mood and anxiety diagnoses, lifetime traumatic brain injury, combat experiences, sleep quality, and alcohol use. Hierarchical regression models were used to determine the association of these conditions with current pain. Average pain for the previous 30 days, assessed with the McGill Pain Questionnaire, was 30.07 out of 100 (SD = 25.43). Sleep quality, PTSD symptom severity, and alcohol use were significantly associated with pain (R(2) = .24), as were reexperiencing symptoms of PTSD (R(2) = .25). For participants with a history of chronic pain (n = 65), only PTSD symptoms were associated with pain (R(2) = .19). Current pain severity was associated with increased PTSD severity (notably, reexperiencing symptoms), poor sleep quality, and increased alcohol use. These data support the hypothesis that PTSD symptoms influence pain, but suggest that problems with sleep and alcohol use may exacerbate the relationship.