Five-year Pain Intensity and Treatment Trajectories of Post-9/11 Veterans With Mild Traumatic Brain Injury

The Impact of Non-Pain Factors on Pain Interference Among U.S. Service Members and Veterans with Symptoms of Mild Traumatic Brain Injury

U.S. Service members and Veterans (SM/V) experience elevated rates of traumatic brain injury (TBI), chronic pain, and other non-pain symptoms. However, the role of non-pain factors on pain interference levels remains unclear among SM/Vs, particularly those with a history of TBI. The primary objective of this study was to identify factors that differentiate high/low pain interference, given equivalent pain intensity among U.S. SM/V participating in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) national multi-center prospective longitudinal observational study. An explainable machine learning was used to identify key predictors of pain interference conditioned on equivalent pain intensity. The final sample consisted of n = 1,577 SM/Vs who were predominantly male (87%), and 83.6% had a history of mild TBI(s) (mTBI), while 16.4% were TBI negative controls. The sample was categorized according to pain interference level (Low: 19.9%, Moderate: 52.5%, and High: 27.6%). Both pain intensity scores and pain interference scores increased with the number of mTBIs (p < 0.001), and there was evidence of a dose response between the number of injuries and pain scores. Machine learning models identified fatigue and anxiety as the most important predictors of pain interference, whereas emotional control was protective. Partial dependence plots identified that marginal effects of fatigue and anxiety were associated with pain interference (p < 0.001), but the marginal effect of mTBI was not significant in models considering all variables (p > 0.05). Non-pain factors are associated with functional limitations and disability experience among SM/V with an mTBI history. The functional effects of pain may be mediated through multiple other factors. Pain is a multi-dimensional experience that may benefit most from holistic treatment approaches that target comorbidities and build supports that promote recovery.

Characterizing Extreme Phenotypes for Pain Interference in Persons With Chronic Pain Following Traumatic Brain Injury: A NIDILRR and VA TBI Model Systems Collaborative Project

OBJECTIVE

To define and characterize extreme phenotypes based on pain interference for persons with chronic pain following traumatic brain injury (TBI).

SETTING

Eighteen Traumatic Brain Injury Model System (TBIMS) Centers.

PARTICIPANTS

A total of 1762 TBIMS participants 1 to 30 years post-injury reporting chronic pain at their most recent follow-up interview.

PRIMARY MEASURES

The Brief Pain Inventory (BPI) interference scale, sociodemographic, injury, functional outcome, pain, and treatment characteristics.

RESULTS

Participants were predominantly male (73%), White (75%), middle-aged (mean 46 years), and who were injured in motor vehicle accidents (53%) or falls (20%). Extreme phenotypes were identified based on upper and lower 25th percentiles to create low-interference ( n = 441) and high-interference ( n = 431) extreme phenotypes. Bivariate comparisons found several sociodemographic, injury, function, pain, and treatment differences between extreme phenotype groups, including significant differences ( P < .001) on all measures of concurrent function with those in the low-interference extreme phenotype experiencing better function than those in the high-interference extreme phenotype. Lasso regression combined with logistic regression identified multivariable predictors of low- versus high-interference extreme phenotypes. Reductions in the odds of low- versus high-interference phenotypes were significantly associated with higher pain intensity (odds ratio [OR] = 0.33), having neuropathic pain (OR = 0.40), migraine headache (OR = 0.41), leg/feet pain (OR = 0.34), or hip pain (OR = 0.46), and more pain catastrophizing (OR = 0.81).

CONCLUSION

Results suggest that for those who experience current chronic pain, there is high variability in the experience and impact of pain. Future research is needed to better understand how pain experience impacts individuals with chronic pain and TBI given that pain characteristics were the primary distinguishing factors between phenotypes. The use of extreme phenotypes for pain interference may be useful to better stratify samples to determine efficacy of pain treatment for individuals with TBI.

Characterizing Extreme Phenotypes for Perceived Improvement From Treatment in Persons With Chronic Pain Following Traumatic Brain Injury: A NIDILRR and VA TBI Model Systems Collaborative Project

OBJECTIVE

To define and characterize extreme phenotypes based on perceived improvement in pain for persons with chronic pain following traumatic brain injury (TBI).

SETTING

Eighteen Traumatic Brain Injury Model System (TBIMS) Centers.

PARTICIPANTS

A total of 1762 TBIMS participants 1 to 30 years post-injury reporting chronic pain at their most recent follow-up interview.

PRIMARY MEASURES

The Patient's Global Impression of Change (PGIC) related to pain treatment. Sociodemographic, injury, functional outcome, pain, and pain treatment characteristics.

RESULTS

Participants were mostly male (73%), White (75%), middle-aged (mean 46 years), injured in motor vehicle accidents (53%), or falls (20%). Extreme phenotypes were created for an extreme improvement phenotype ( n = 512, 29.8%) defined as "moderately better" or above on the PGIC and an extreme no-change group ( n = 290, 16.9%) defined as no change or worse. Least absolute shrinkage and selection operator (LASSO) regression combined with logistic regression identified multivariable predictors of improvement versus no-change extreme phenotypes. Higher odds of extreme improvement phenotype were significantly associated with being female (odds ratio [OR] = 1.85), married versus single (OR = 2.02), better motor function (OR = 1.03), lower pain intensity (OR = 0.78), and less frequent pain, especially chest pain (OR = 0.36). Several pain treatments were associated with higher odds of being in the extreme improvement versus no-change phenotypes including pain medication (OR = 1.85), physical therapy (OR = 1.51), yoga (OR = 1.61), home exercise program (OR = 1.07), and massage (OR = 1.69).

CONCLUSION

Investigation of extreme phenotypes based on perceived improvement with pain treatment highlights the ability to identify characteristics of individuals based on pain treatment responsiveness. A better understanding of the biopsychosocial characteristics of those who respond and do not respond to pain treatments received may help inform better surveillance, monitoring, and treatment. With further research, the identification of risk factors (such as pain intensity and frequency) for treatment response/nonresponse may provide indicators to prompt changes in care for individuals with chronic pain after TBI.

Caring again: Support for parent caregivers of wounded, ill, and/or injured adult children veterans

BACKGROUND

Parents often provide care to adult children veterans with polytrauma, traumatic brain injury, and/or post-traumatic stress disorder.

OBJECTIVE

This two-arm randomized clinical trial compared interventions to help parent caregivers improve their depression, anxiety, and burden and manage care by decreasing troubling and concerning behaviors.

METHODS

Interventions were six one-hour structured one-on-one behavioral sessions (REACH) or six 30-minute prerecorded online educational webinars. Both focused on knowledge, strategies for care, and coping, but REACH sessions were targeted, interactive, and skills-based. Quantitative and qualitative data were collected by telephone. Quantitative analyses included chi-squared test or independent samples t-test and repeated measures mixed linear modeling, with theme development for qualitative data.

RESULTS

There were 163 parent caregivers, mostly mothers. During six months, participants in both arms improved significantly in depression, anxiety, burden, and reported veteran troubling and concerning behaviors. REACH caregivers showed a group by time improvement in concerning behaviors. Benefits included resources, self-reflection, not feeling alone, new skills, improved self-efficacy, and helping others. Specific concerns include exclusion from military and veteran care briefings and concern for the future.

CONCLUSION

The positive response to both interventions provides opportunities for organizations with varying resources to provide support for parent caregivers. Interventions need to be targeted to parents' particular concerns and needs.

Characteristics of Responders and Nonresponders in a Military Postconcussion Rehabilitation Program

OBJECTIVE

To characterize treatment responders and nonresponders as measured by the Neurobehavioral Symptom Inventory (NSI) in order to understand whether certain traits in our patient population would characterize favorable response.

SETTING

Brain Injury Rehabilitation Service at Brooke Army Medical Center, Fort Sam Houston, San Antonio, Texas.

PATIENTS

In total, 655 active duty military patients with a diagnosis of mild traumatic brain injury (mTBI) who received treatment between 2007 and 2020 and completed self-report measures as part of routine care.

DESIGN

Observational retrospective analysis of outpatient clinical outcomes data.

MAIN MEASURES

The primary outcome measure was the NSI, divided into the responder and nonresponder groups. Responders were defined by reliable change in NSI total score (decrease of ≥8 points from intake to discharge).

FINDINGS

Responders (n = 395) reported a higher level of symptom burden at intake on the NSI. Women responded proportionally more (70%) than men (58%). After treatment, responders reported improvements on all measures evaluated while nonresponders reported no change or slightly worse symptoms. Logistic regression analysis showed that posttraumatic stress symptoms at intake decreased odds of favorable treatment response while satisfaction with social relationships increased odds of favorable treatment response.

CONCLUSION

The results from this process improvement project suggested that posttraumatic symptoms warrant programmatic attention in TBI clinics while social relationships may be a protective factor that can be capitalized to enhance troop readiness. Systematic examination of these characteristics should be conducted on a larger population within the military health system.

Persistence of significant pain interference following substance use disorder remission: Negative association with psychosocial and physical recovery

BACKGROUND

Although substance use disorder (SUD) is frequently complicated by pain, the prevalence and correlates of persistent pain and dysfunction following SUD remission have not been studied.

METHODS

Using a cross-sectional sample of United States (US) adults with SUD identified in the National Epidemiologic Survey on Alcohol and Related Conditions Wave III, we evaluated the prevalence of moderate/severe pain interference (PI) in subgroups with current and remitted SUD and the independent association of SUD remission and PI with self-reported psychosocial and physical function (Mental Health Composite Score [MCS] and Physical Function Score [PFS] from the Short Form 12).

RESULTS

A fifth (20.6%; 7.6 million) of estimated 36.7 million US adults with past year SUD and a slightly higher proportion (25.6%; 9.6 million) of 37.4 million with SUD remission reported PI. MCS and PFS showed independent negative associations with PI among adults with both past year SUD and SUD remission. MCS had a positive independent association with SUD remission, but a stronger negative association with PI. While PFS had no statistically significant association with SUD remission, it had a strong negative association with PI. Analysis of interaction between SUD remission and PI revealed that SUD remission had no effect on the association of PI and MCS but had significant moderating influence on the association between PI and PFS.

CONCLUSIONS

Moderate to severe pain interference continues to be a significant problem among a sizable population achieving SUD remission potentially impeding recovery, and deserves focused clinical attention both active SUD and its remission.

Understanding Traumatic Brain Injury in Females: A State-of-the-Art Summary and Future Directions

In this report, we identify existing issues and challenges related to research on traumatic brain injury (TBI) in females and provide future directions for research. In 2017, the National Institutes of Health, in partnership with the Center for Neuroscience and Regenerative Medicine and the Defense and Veterans Brain Injury Center, hosted a workshop that focused on the unique challenges facing researchers, clinicians, patients, and other stakeholders regarding TBI in women. The goal of this "Understanding TBI in Women" workshop was to bring together researchers and clinicians to identify knowledge gaps, best practices, and target populations in research on females and/or sex differences within the field of TBI. The workshop, and the current literature, clearly highlighted that females have been underrepresented in TBI studies and clinical trials and have often been excluded (or ovariectomized) in preclinical studies. Such an absence in research on females has led to an incomplete, and perhaps inaccurate, understanding of TBI in females. The presentations and discussions centered on the existing knowledge regarding sex differences in TBI research and how these differences could be incorporated in preclinical and clinical efforts going forward. Now, a little over 2 years later, we summarize the issues and state of the science that emerged from the "Understanding TBI in Women" workshop while incorporating updates where they exist. Overall, despite some progress, there remains an abundance of research focused on males and relatively little explicitly on females.