Longitudinal interactions of pain and posttraumatic stress disorder symptoms in U.S. Military service members following blast exposure

MMPI-2-RF Profiles of Treatment-Seeking Veterans in a VA Pain Clinic and Associations with Markers of Physical Performance

Chronic pain is a debilitating condition for many military Veterans and is associated with posttraumatic stress disorder (PTSD). This study examined the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in 144 Veterans (88.2% male, mean age = 57.95 years) recruited from a VA outpatient pain clinic and associations with self-reported pain severity, pain-related interference in daily activities, prescription opioid use, and objective metrics of physical performance on tasks impacted by pain (walking, stair climbing, grip strength, indexed by a single latent variable). Among the cohort with valid responses on the MMPI-2-RF (n = 117) and probable PTSD, mean Somatic Complaints (RC1) and Ideas of Persecution (RC6) scores were clinically elevated. All MMPI-2-RF scales were more strongly correlated with self-reported pain interference than severity. Regressions revealed associations between self-rated pain interference (but not pain or PTSD severity) and physical performance scores (β = .36, p = .001). MMPI-2-RF overreporting Validity and Higher-Order scales contributed incremental variance in predicting physical performance, including Infrequent Psychopathology Responses (β = .33, p = .002). PTSD severity was associated with prescription opioid use when accounting for the effects of over-reported somatic and cognitive symptoms (odds ratio 1.05, p ≤ .025). Results highlight the role of symptom overreporting and perceptions of functional impairment to observable behaviors among individuals with chronic pain.

Time doesn't heal all: PTSD symptoms exacerbate the relationship between age and pain intensity

Objective

Posttraumatic stress disorder (PTSD) symptoms and pain interfere with daily functioning and quality of life for many combat Veterans. As individuals age, pain symptoms tend to increase whereas PTSD symptoms tend to decrease. PTSD symptoms exacerbate pain, but the nature of this relationship across the aging process is unclear. The purpose of this study was to determine how PTSD symptoms affect the association between age and pain intensity.

Methods

Participants in this cross-sectional study included 450 Veterans (80% male) who served after September 11, 2001. PTSD and pain intensity ratings were assessed by the PTSD Checklist for DSM-5 (PCL-5) and the Brief Pain Inventory (BPI), respectively. Hierarchical multiple linear regression evaluated main and interaction effects between age, PTSD symptoms, and pain intensity.

Results

Age (B = 0.04, p < 0.001) and PTSD symptoms (B = 0.05, p < 0.001) were positively associated with pain intensity. Age and PTSD symptoms were inversely correlated (r = -0.16, p < 0.001). PTSD symptoms exacerbated the relationship between age and pain intensity (ΔR2 = 0.01, p = 0.036). Specifically, when greater PTSD symptoms were reported at older ages, pain intensity was significantly higher.

Conclusion

Results of these analyses suggests that age is important when considering the effects of PTSD symptoms on pain intensity ratings. Specifically, pain intensity ratings are higher in older Veterans with PTSD symptoms. These findings underscore the importance for clinical providers to evaluate trauma history and PTSD symptoms in older Veterans reporting pain symptoms.

Exploring combat stress exposure effects on burn pain in a female rodent model

In the military, constant physiological and psychological stress encountered by Soldiers can lead to development of the combat and operational stress reaction (COSR), which can effect pain management. Similar effects are seen in other populations subjected to high levels of stress. Using a model of COSR, our lab recently showed that four weeks of stress prior to an injury increases pain sensitivity in male rats. With the roles of women in the military expanding and recent studies indicating sex differences in stress and pain processing, this study sought to investigate how different amounts of prior stress exposure affects thermal injury-induced mechanosensitivity in a female rat model of COSR. Adult female Sprague Dawley rats were exposed to the unpredictable combat stress (UPCS) procedure for either 2 or 4 weeks. The UPCS procedure included exposure to one stressor each day for four days. The stressors include: (1) sound stress for 30 min, (2) restraint stress for 4 h, (3) cold stress for 4 h, and (4) forced swim stress for 15 min. The order of stressors was randomized weekly. Mechanical and thermal sensitivity was tested twice weekly. After the UPCS procedure, a sub-set of rats received a thermal injury while under anesthesia. The development of mechanical allodynia and thermal hyperalgesia was examined for 14 days post-burn. UPCS exposure increased mechanosensitivity after two weeks. Interestingly, with more stress exposure, females seemed to habituate to the stress, causing the stress-induced changes in mechanosensitivity to decrease by week three of UPCS. If thermal injury induction occurred during peak stress-induced mechanosensitivity, after two weeks, this resulted in increased mechanical allodynia in the injured hind paw compared to thermal injury alone. This data indicates a susceptibility to increased nociceptive sensitization when injury is sustained at peak stress reactivity. Additionally, this data indicates a sex difference in the timing of peak stress. Post-mortem examination of the prefrontal cortex (PFC) showed altered expression of p-TrkB in 4-week stressed animals given a thermal injury, suggesting a compensatory mechanism. Future work will examine treatment options for preventing stress-induced pain to maintain the effectiveness and readiness of the Warfighter.

Risk Factors to Persistent Pain Following Musculoskeletal Injuries: A Systematic Literature Review

Background: Musculoskeletal (MSK) injury is one of the major causes of persistent pain. Objective: This systematic literature review explored the factors that lead to persistent pain following a MSK injury in the general population, including athletes. Methods: A primary literature search of five electronic databases was performed to identify cohort, prospective, and longitudinal trials. Studies of adults who diagnosed with a MSK injury, such as sprains, strains or trauma, were included. Results: Eighteen studies involving 5372 participants were included in this review. Participants’ ages ranged from 18–95 years. Most of the included studies were of prospective longitudinal design. Participants had a variety of MSK injuries (traumatic and non-traumatic) causing persistent pain. Multiple factors were identified as influencing the development of persistent pain following a MSK injury, including high pain intensity at baseline, post-traumatic stress syndrome, presence of medical comorbidities, and fear of movement. Scarcity of existing literature and the heterogeneity of the studies made meta-analysis not possible. Conclusions: This systematic review highlighted factors that might help predict persistent pain and disability following MSK injury in the general population, including athletes. Identification of these factors may help clinicians and other health care providers prevent the development of persistent pain following a MSK injury.

Co-occurrence of severe PTSD, somatic symptoms and dissociation in a large sample of childhood trauma inpatients: a network analysis

Co-occurrence of mental disorders including severe PTSD, somatic symptoms, and dissociation in the aftermath of trauma is common and sometimes associated with poor treatment outcomes. However, the interrelationships between these conditions at symptom level are not well understood. In the present study, we aimed to explore direct connections between PTSD, somatic symptoms, and dissociation to gain a deeper insight into the pathological processes underlying their comorbidity that can inform future treatment plans. In a sample of 655 adult inpatients with a diagnosis of severe PTSD following childhood abuse (85.6% female; mean age = 47.57), we assessed symptoms of PTSD, somatization, and dissociation. We analyzed the comorbidity structure using a partial correlation network with regularization. Mostly positive associations between symptoms characterized the network structure. Muscle or joint pain was among the most central symptoms. Physiological reactivation was central in the full network and together with concentrations problems acted as bridge between symptoms of PTSD and somatic symptoms. Headaches connected somatic symptoms with others and derealization connected dissociative symptoms with others in the network. Exposure to traumatic events has a severe and detrimental effect on mental and physical health and these consequences worsen each other trans-diagnostically on a symptom level. Strong connections between physiological reactivation and pain with other symptoms could inform treatment target prioritization. We recommend a dynamic, modular approach to treatment that should combine evidence-based interventions for PTSD and comorbid conditions which is informed by symptom prominence, readiness to address these symptoms and preference.

Differential Pain Presentations Observed Across Post-Traumatic Stress Disorder Symptom Trajectories After Combat Injury

OBJECTIVE

This study evaluated the association between pain outcomes and post-traumatic stress disorder (PTSD) symptom trajectories after combat-related injury, while adjusting for receipt of regional anesthesia (RA) soon after injury.

METHODS

The PTSD symptom trajectories of N = 288 combat-injured service members were examined from within a month of injury up to two-years after. Linear mixed-effects models evaluated the association between PTSD symptom trajectories and average pain and pain interference outcomes while adjusting for receipt of RA during combat casualty care.

RESULTS

Four PTSD trajectories were characterized: resilient, recovering, worsening, and chronic. Differential pain presentations were associated with PTSD symptom trajectories, even after adjusting for receipt of RA. Compared to those with a resilient PTSD symptom trajectory, individuals presenting with chronic PTSD trajectories were estimated to experience average pain scores 2.61 points higher (95% CI: 1.71, 3.14). Participants presenting with worsening (β = 1.42; 95% CI: 0.77, 1.78) and recovering PTSD trajectories (β = 0.65; 95% CI: 0.09, 1.08) were estimated to experience higher average pain scores than participants with resilient PTSD trajectories. Significant differences in pain interference scores were observed across PTSD trajectories. Receiving RA was associated with improved pain up to two years after injury (β =-0.31; 95% CI: -0.90, -0.04), however no statistically significant association was detected between RA and PTSD trajectories.

CONCLUSIONS

PTSD trajectories were associated with greater pain intensity and interference following combat injury even when accounting for receipt of early RA for pain management. These findings underscore the need to jointly assess pain and PTSD symptoms across the trauma care continuum.

Predictors of Veterans Health Administration utilization and pain persistence among soldiers treated for postdeployment chronic pain in the Military Health System

BACKGROUND

Chronic pain presents a significant burden for both federal health care systems designed to serve combat Veterans in the United States (i.e., the Military Health System [MHS] and Veterans Health Administration [VHA]), yet there have been few studies of Veterans with chronic pain that have integrated data from both systems of care. This study examined 1) health care utilization in VHA as an enrollee (i.e., linkage to VHA) after military separation among soldiers with postdeployment chronic pain identified in the MHS, and predictors of linkage, and 2) persistence of chronic pain among those utilizing the VHA.

METHODS

Observational, longitudinal study of soldiers returning from a deployment in support of the Afghanistan/Iraq conflicts in fiscal years 2008-2014. The analytic sample included 138,206 active duty soldiers for whom linkage to VHA was determined through FY2019. A Cox proportional hazards model was estimated to examine the effects of demographic characteristics, military history, and MHS clinical characteristics on time to linkage to VHA after separation from the military. Among the subpopulation of soldiers who linked to VHA, we described whether they met criteria for chronic pain in the VHA and pain management treatments received during the first year in VHA.

RESULTS

The majority (79%) of soldiers within the chronic pain cohort linked to VHA after military separation. Significant predictors of VHA linkage included: VHA utilization as a non-enrollee prior to military separation, separating for disability, mental health comorbidities, and being non-Hispanic Black or Hispanic. Soldiers that separated because of misconduct were less likely to link than other soldiers. Soldiers who received nonpharmacological treatments, opioids/tramadol, or mental health treatment in the MHS linked earlier to VHA than soldiers who did not receive these treatments. Among those who enrolled in VHA, during the first year after linking to the VHA, 49.7% of soldiers met criteria for persistent chronic pain in VHA.

CONCLUSIONS

The vast majority of soldiers identified with chronic pain in the MHS utilized care within VHA after military separation. Careful coordination of pain management approaches across the MHS and VHA is required to optimize care for soldiers with chronic pain.

Factors Associated with the Development of Persistent Pain after mTBI

BACKGROUND

Persistent pain after mild traumatic brain injury (mTBI) is widely experienced, yet little is known about who is at risk for experiencing persistent pain after their injury.

AIMS

The purpose of this study was to 1) determine if there are factors associated with later experiencing persistent pain after mTBI and 2) examine if there are symptom patterns associated with the experience of persistent pain.

DESIGN

Secondary analysis was conducted using de-identified data from an NIH-funded longitudinal study.SettingsParticipants were enrolled in the emergency department.

PARTICIPANTS

Participants were aged 21 to 92 and all had experienced mTBI.

METHODS

We examined baseline characteristics, symptoms, and injury related variables associated with the endorsement of persistent pain among those with mTBI (N = 183) from baseline to 6 months post-injury. In order to identify a persistent pain phenotype, exploratory factor analysis was used to determine which symptoms co-occur with persistent pain.

RESULTS

Persistent pain was found in 78% of those with mTBI. Those with lower overall health status at day 7 and at 1-month following injury had greater odds of developing persistent pain. Those with higher levels of general health status and physical function health status at day 7 and 1 month, and those with higher levels of overall health related status at 1 month had significantly lesser odds of persistent pain at 6 months. Factor analysis revealed that persistent pain and co-occurring symptoms (anxiety, depression, dizziness, nausea and vomiting, sleep disturbance, poor memory, poor concentration, longer to think and light sensitivity) loaded on one factor, indicating that these symptoms are associated.

CONCLUSIONS

Those at increased risk for persistent pain should be screened beginning early in the recovery trajectory to reduce their risk of developing persistent pain. Identification of a phenotype offers potential for recognition of symptoms that cluster with persistent pain, improving the ability to treat patients more holistically, and develop interventions to support recovery from injury.

Opioid and Nonpharmacologic Treatments Among Soldiers With Chronic Pain and Posttraumatic Stress Disorder

OBJECTIVE

This study examined the prevalence of chronic pain alone, posttraumatic stress disorder (PTSD) alone, and both chronic pain and PTSD among U.S. Army soldiers during the postdeployment year.

METHODS

The sample was 576,425 active duty soldiers returning from deployment in Afghanistan or Iraq between October 1, 2008, and September 30, 2014. Bivariate statistics were used to compare health care utilization among subgroups. Multivariate logistic regression with additional covariates was used to identify predictors of receiving an opioid days' supply of >30 days in the postdeployment year among soldiers with chronic pain, focusing on the effect of PTSD alone and on an interaction of PTSD with nonpharmacologic treatments (including therapeutic exercise, chiropractic treatment, acupuncture, and biofeedback).

RESULTS

In total, 12.2% of the soldiers received a chronic pain diagnosis, 5.1% a PTSD diagnosis, and 1.8% had both. Among soldiers with both conditions, 80.3% received nonpharmacologic treatment, and 31.4% received an opioid days' supply of >30 days. Among soldiers with chronic pain, comorbid PTSD and lack of nonpharmacologic treatment was associated with increased odds of receiving an opioid days' supply of >30 days (odds ratio [OR]=1.4, 95% confidence interval [CI]=1.3-1.6). PTSD combined with specific nonpharmacologic treatment modalities had a variable relationship with opioid receipt, and only PTSD with acupuncture or biofeedback was associated with reduced odds (OR=0.8, 95% CI=0.7-0.9).

CONCLUSIONS

Soldiers having both chronic pain and PTSD have significant health care needs. Although these soldiers accessed mental health care and received nonpharmacologic treatment, additional interventions are needed to mitigate protracted opioid utilization.

Early Pain and Other Somatic Symptoms Predict Posttraumatic Stress Reactions in Survivors of Terrorist Attacks: The Longitudinal Utøya Cohort Study

Survivors of traumatic events commonly suffer from long-term pain and related somatic symptomatology. To test the predominant hypothesis that survivors' pain comprises sequela of persistent posttraumatic stress symptoms (PTSS), we assessed the sequential order of symptom development among young survivors of a terrorist attack. All 490 survivors of the 2011 Utøya (Norway) attacks were invited to the longitudinal Utøya cohort study; 355 (72.4%) participated. The mean survivor age was 19.3 years (SD = 4.6) and 169 were female (47.6%). Somatic symptoms, including headache, other pain and fatigue, and PTSS, were measured 4-5 months (T1), 14-16 months (T2), and 32-33 months (T3) after the attack. Longitudinal associations between somatic symptoms and PTSS were assessed in cross-lagged structural equation model (SEM) analyses, which were adjusted for known confounders. Higher pain levels and other somatic symptoms at T1 consistently predicted PTSS at T2 in SEM analyses, r = .473, p < .001. Beyond this early-to-intermediate posttraumatic phase, somatic symptoms did not significantly predict PTSS: T2-T3, r = .024, p = .831; T1-T3, r = -.074, p = .586. PTSS did not significantly predict later somatic symptomatology at T1-T2, r = .093, p = .455; T2-T3, r = .272, p = .234; or T1-T3, r = -.279, p = .077. The findings indicate that survivors' early pain and related somatic symptoms strongly and consistently predict later psychopathology. After severe psychological trauma, early interventions may need to address individuals' pain to hinder chronification.

Bidirectionality of Pain Interference and PTSD Symptoms in Military Veterans: Does Injury Status Moderate Effects?

OBJECTIVE

Pain and post-traumatic stress disorder (PTSD) symptoms are strongly correlated in veteran populations. Arguments for which one condition predicts or worsens the other condition have gone in both directions. However, research addressing this issue has been primarily limited to cross-sectional studies rather than examinations of a potential bidirectional relationship between pain interference and PTSD symptoms over time. In addition, no studies have examined deployment injury status as potentially moderating this bidirectional effect in veterans. To address these gaps in the literature, the present longitudinal study examined whether there is a bidirectional relationship between pain interference and PTSD symptoms in a sample of male and female veterans returning from Operation Iraqi Freedom, Operation Enduring Freedom, or Operation New Dawn (N = 729) and whether deployment injury status moderates this relationship.

METHODS

Participants completed phone interviews regarding pain interference and PTSD symptoms at three time points, each three months apart.

RESULTS

Pain interference at Time 1 predicted worse PTSD symptoms at Time 2 for the subset of veterans who sustained injuries during deployment (n = 381) but not for veterans with pain interference who did not sustain injuries (n = 338). From Time 1 to Time 3, elevations in PTSD symptoms were mediated by pain interference for injured veterans; in contrast, PTSD symptoms did not appear to drive changes in pain interference in either group.

CONCLUSIONS

These results indicate that physical symptom management should be a crucial target of psychological intervention for returning veterans with PTSD symptoms and deployment-related injuries.

The role of sleep quality on the relationship between posttraumatic stress symptoms and pain in women

Pain frequently co-occurs with elevated posttraumatic stress symptoms (PTSS); women are at elevated risk for their co-occurrence. PTSS and pain are associated with poor sleep quality; yet, little research has examined how sleep impacts their co-occurrence. The current study examines the indirect role of sleep on the relationship between PTSS and pain. A community sample of 182 women completed psychometrically-sound questionnaires assessing PTSS, sleep quality, pain characteristics, depression and anxiety symptoms, and anxiety sensitivity. We examined how sleep quality impacted associations among PTSS and pain intensity and pain interference, while controlling for key psychological factors. Greater PTSS was associated with worse pain interference, and poor sleep quality had a significant indirect effect on this relationship. Sleep may represent a modifiable behavioral mechanism that contributes to the mutual maintenance of PTSS and pain in women. Future research is needed to further clarify the role of sleep quality in their co-occurrence.

Mutual maintenance of PTSD and physical symptoms for Veterans returning from deployment

Background: The mutual maintenance model proposes that post-traumatic stress disorder (PTSD) symptoms and chronic physical symptoms have a bi-directional temporal relationship. Despite widespread support for this model, there are relatively few empirical tests of the model and these have primarily examined patients with a traumatic physical injury. Objective: To extend the assessment of this model, we examined the temporal relationship between PTSD and physical symptoms for military personnel deployed to combat (i.e., facing the risk of death) who were not evacuated for traumatic injury. Methods: The current study used a prospective, longitudinal design to understand the cross-lagged relationships between PTSD and physical symptoms before, immediately after, 3 months after, and 1 year after combat deployment. Results: The cross-lagged results showed physical symptoms at every time point were consistently related to greater PTSD symptoms at the subsequent time point. PTSD symptoms were related to subsequent physical symptoms, but only at one time-point with immediate post-deployment PTSD symptoms related to physical symptoms at three months after deployment. Conclusion: The findings extend prior work by providing evidence that PTSD and physical symptoms may be mutually maintaining even when there is not a severe traumatic physical injury.

Do post-traumatic pain and post-traumatic stress symptomatology mutually maintain each other? A systematic review of cross-lagged studies

After traumatic exposure, individuals are at risk of developing symptoms of both pain and post-traumatic stress disorder (PTSD). Theory and research suggest a complex and potentially mutually maintaining relationship between these symptomatologies. However, findings are inconsistent and the applied methods are not always well suited for testing mutual maintenance. Cross-lagged designs can provide valuable insights into such temporal associations, but there is a need for a systematic review to assist clinicians and researchers in understanding the nature of the relationship. Thus, the aim of this systematic review was to identify, critically appraise, and synthesize results from cross-lagged studies on pain and PTSD symptomatology to assess the evidence for longitudinal reciprocity and potential mediators. Systematic searches resulted in 7 eligible studies that were deemed of acceptable quality with moderate risk of bias using the cohort study checklist from Scottish Intercollegiate Guidelines Network. Furthermore, synthesis of significant pathways in the cross-lagged models showed inconsistent evidence of both bidirectional and unidirectional interaction patterns between pain and PTSD symptomatology across time, hence not uniformly supporting the theoretical framework of mutual maintenance. In addition, the synthesis suggested that hyperarousal and intrusion symptoms may be of particular importance in these cross-lagged relationships, while there was inconclusive evidence of catastrophizing as a mediator. In conclusion, the findings suggest an entangled, but not necessarily mutually maintaining relationship between pain and PTSD symptomatology. However, major variations in findings and methodologies complicated synthesis, prompting careful interpretation and heightening the likelihood that future high-quality studies will change these conclusions.

Examining the relationship and clinical management between traumatic brain injury and pain in military and civilian populations

In this review, we discuss the comorbidity of traumatic brain injury (TBI) and pain among civilians and military members, the common causes of pain resulting from TBI, and offer insight about the therapeutic management of TBI symptoms and pain. Traumatic brain injury (TBI) is a debilitating health problem and one of the most common post-TBI symptoms is pain, which can contribute to psychological issues such as Post-traumatic stress disorder (PTSD) and depression. Headache pain appears to be the most common type of pain that results from TBI, yet pain can also be more widespread. Managing TBI symptoms and pain simultaneously is difficult because extensive randomized control and clinical studies assessing the effectiveness of therapeutic approaches are lacking. Pharmacological agents such as antidepressants and Triptans and nonpharmacological therapies such as cognitive rehabilitation and physical therapies are commonly used yet it is unknown how effective these therapies are in the long-term. A combination of pharmacological and non-pharmacological therapies is often more effective for managing TBI symptoms and pain than either treatment alone. However, future research is needed to determine the most therapeutic approaches for managing the comorbidity of pain and TBI symptoms in the long term. This review offers suggestions for such future studies.

Chronic Effects of Neurotrauma Consortium (CENC) multicentre study interim analysis: Differences between participants with positive versus negative mild TBI histories

OBJECTIVES

Compare characteristics and outcomes of combat-exposed military personnel with positive versus negative mild traumatic brain injury (mTBI) histories.

SETTING

Recruitment was from registration lists and ambulatory clinics at four veterans administration hospitals.

PARTICIPANTS

Consented veterans and service members completing initial evaluation by September 2016 (n = 492).

DESIGN

Observational with cross-sectional analyses.

MAIN MEASURES

Multimodal assessments including structured interviews, record review, questionnaires, neuroendocrine labs and neurocognitive and sensorimotor performance.

RESULTS

In unadjusted comparisons to those absent lifetime mTBI, the mTBI positive group (84%) had greater combat exposure, more potential concussive events, less social support and more comorbidities, including asthma, sleeping problems and post-traumatic stress disorder. They also fared worse on all sensory and pain symptom scores and self-reported functional and global outcomes. They had poorer scores on Wechsler Adult Intelligence Scale-IV coding (processing speed), TMT-B (visual-motor integration and executive function) and two posturography subtests, but were otherwise equal to TBI negative participants on neurocognitive and sensorimotor testing and neuroendocrine levels.

CONCLUSIONS

Although differences in characteristics exist which were not adjusted for, participants with historical mTBI have greater symptomatology and life functioning difficulties compared with non-TBI. Performance measures were less dissimilar between groups. These findings will guide further research within this accruing cohort.

Chronic Pain Types Differ in Their Reported Prevalence of Post -Traumatic Stress Disorder (PTSD) and There Is Consistent Evidence That Chronic Pain Is Associated with PTSD: An Evidence-Based Structured Systematic Review

Objectives

The hypotheses of this systematic review were the following: 1) Prevalence of post-traumatic stress disorder (PTSD) will differ between various types of chronic pain (CP), and 2) there will be consistent evidence that CP is associated with PTSD.

Methods

Of 477 studies, 40 fulfilled the inclusion/exclusion criteria of this review and were grouped according to the type of CP. The reported prevalence of PTSD for each grouping was determined by aggregating all the patients in all the studies in that group. Additionally all patients in all groupings were combined. Percentage of studies that had found an association between CP and PTSD was determined. The consistency of the evidence represented by the percentage of studies finding an association was rated according to the Agency for Health Care Policy and Research guidelines.

Results

Grouping PTSD prevalence differed ranging from a low of 0.69% for chronic low back pain to a high of 50.1% in veterans. Prevalence in the general population with CP was 9.8%. Of 19 studies, 16 had found an association between CP and PTSD (84.2%) generating an A consistency rating (consistent multiple studies). Three of the groupings had an A or B (generally consistent) rating. The veterans grouping received a C (finding inconsistent) rating.

Conclusion

The results of this systematic review confirmed the hypotheses of this review.

The role of posttraumatic stress symptoms on chronic pain outcomes in chronic pain patients referred to rehabilitation

Objectives

Posttraumatic stress symptoms (PTSS) are highly prevalent in chronic pain patients and may affect pain symptomatology negatively, but there is still a great need to explore exactly how this occurs. Therefore, this study investigated differences in pain intensity, pain-related disability, and psychological distress between chronic pain patients not exposed to a trauma, patients exposed to a trauma with no PTSS, and patients exposed to a trauma with PTSS. Moreover, the moderating effects of PTSS on the associations between pain intensity and pain-related disability and psychological distress were investigated.

Methods

In this cross-sectional cohort study, data were consecutively collected over the course of a year in patients with chronic non-malignant pain referred for multidisciplinary pain rehabilitation at a Danish university hospital pain center using questionnaires assessing pain, pain-related disability, PTSS, anxiety, and depression.

Results

The final sample consisted of 682 chronic pain patients, who were divided into three subgroups (no trauma, 40.6%; trauma/no PTSS, 40.5%; trauma/PTSS, 18.9%). Chronic pain patients with PTSS reported significantly higher levels of pain intensity, pain-related disability, depression, and anxiety compared to chronic pain patients without a trauma and chronic pain patients without PTSS. Moreover, PTSS significantly moderated the associations between pain intensity and pain-related psychosocial disability, depression, and anxiety.

Conclusion

These results highlight the importance of assessing PTSS in chronic pain patients and suggest that PTSS have a specific influence on the association between pain intensity and more psychosocial aspects of the pain condition.

Complexity of the Relationships of Pain, Posttraumatic Stress, and Depression in Combat-Injured Populations: An Integrative Review to Inform Evidence-Based Practice

BACKGROUND

Understanding the complex interrelationships between combat injuries, physical health, and mental health symptoms is critical to addressing the healthcare needs of wounded military personnel and veterans. The relationship between injury characteristics, pain, posttraumatic stress disorder (PTSD), and depression among combat-injured military personnel is unique to modern conflicts and understudied in the nursing literature.

AIM

This integrative review synthesizes clinical presentations and relationships of combat injury, PTSD, depression, and pain in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) United States military service members and veterans.

METHODS

A literature search was conducted using relative key terms across databases to identify peer-reviewed publications between 2001 and 2016 that examined health outcomes of combat-injured persons in OEF and OIF. The quality of evidence was evaluated and results synthesized to examine the association of combat injury as a risk factor for PTSD, the relationship of PTSD and depression pre- and postinjury, and pain management throughout care.

RESULTS

Twenty-two articles were included in this review. Greater injury and pain severity poses risks for developing PTSD following combat injury, while early symptom management lessens risks for PTSD. Depression appears to be both a contributing risk factor to postinjury PTSD, as well as a comorbidity.

LINKING EVIDENCE TO ACTION

Findings demonstrate a compelling need for improvements in standardized assessment of pain and mental health symptoms across transitions in care. This integrative review informs nurse researchers and providers of the clinical characteristics of pain, PTSD, and depression following combat injury and offers implications for future research promoting optimal surveillance of symptoms.

Repeat low-level blast exposure increases transient receptor potential vanilloid 1 (TRPV1) and endothelin-1 (ET-1) expression in the trigeminal ganglion

Blast-associated sensory and cognitive trauma sustained by military service members is an area of extensively studied research. Recent studies in our laboratory have revealed that low-level blast exposure increased expression of transient receptor potential vanilloid 1 (TRPV1) and endothelin-1 (ET-1), proteins well characterized for their role in mediating pain transmission, in the cornea. Determining the functional consequences of these alterations in protein expression is critical to understanding blast-related sensory trauma. Thus, the purpose of this study was to examine TRPV1 and ET-1 expression in ocular associated sensory tissues following primary and tertiary blast. A rodent model of blast injury was used in which anesthetized animals, unrestrained or restrained, received a single or repeat blast (73.8 ± 5.5 kPa) from a compressed air shock tube once or daily for five consecutive days, respectively. Behavioral and functional analyses were conducted to assess blast effects on nocifensive behavior and TRPV1 activity. Immunohistochemistry and Western Blot were also performed with trigeminal ganglia (TG) to determine TRPV1, ET-1 and glial fibrillary associated protein (GFAP) expression following blast. Increased TRPV1, ET-1 and GFAP were detected in the TG of animals exposed to repeat blast. Increased nocifensive responses were also observed in animals exposed to repeat, tertiary blast as compared to single blast and control. Moreover, decreased TRPV1 desensitization was observed in TG neurons exposed to repeat blast. Repeat, tertiary blast resulted in increased TRPV1, ET-1 and GFAP expression in the TG, enhanced nociception and decreased TRPV1 desensitization.

Trauma-Related Pain, Reexperiencing Symptoms, and Treatment of Posttraumatic Stress Disorder: A Longitudinal Study of Veterans

Research has demonstrated a strong positive association between posttraumatic stress disorder (PTSD) symptoms and physical pain. However, few studies have explored the impact of pain problems on the symptoms and treatment of PTSD, and results remain inconsistent. This longitudinal study examined whether trauma-related and trauma-unrelated pain differentially and uniquely predicted reexperiencing symptoms. We also examined whether levels of reexperiencing symptoms mediated the relationship between pain intensity and posttreatment symptoms of avoidance, numbing, and hyperarousal (ANH). Analyses were conducted using archival data from 99 treatment-seeking veterans who reported the etiology and intensity of their pain and severity of PTSD symptoms pre- and posttreatment. Among veterans with trauma-related pain, pain intensity (a) uniquely corresponded to greater posttreatment reexperiencing symptoms (b = 1.09), and (b) was indirectly predictive of ANH symptoms via the reexperiencing symptoms (b = 1.93). However, veterans with trauma-unrelated pain evidenced no associations between pain intensity and reexperiencing (b = 0.04) or ANH symptoms (b = 0.06). We thus found that trauma-related pain was indirectly related to poor PTSD treatment outcomes via reexperiencing symptoms. These findings offer additional insight into factors that may influence PTSD treatment outcomes for pain-suffering trauma survivors.

A randomized controlled trial of brief Somatic Experiencing for chronic low back pain and comorbid post-traumatic stress disorder symptoms

Background: It is well documented that comorbid post-traumatic stress disorder (PTSD) in chronic pain is associated with a more severe symptom profile with respect to pain, disability and psychological distress. However, very few intervention studies exist targeting both PTSD and pain. The current study is the first randomized controlled trial evaluating the effect of the body-oriented trauma approach of Somatic Experiencing (SE) for comorbid PTSD and low back pain. Although the method is well recognized by clinicians and widely used, SE still needs to be tested in a randomized clinical trial in comparison with an active control group. Objective: The aim of the current study was to compare the effect of an SE intervention in addition to treatment-as-usual (TAU) for patients with chronic low back pain and comorbid PTSD compared to TAU alone. Method: The study was a two-group randomized controlled clinical trial. A cohort of patients (n = 1045) referred to a large Danish spine centre between February 2013 and October 2014 were screened for PTSD and randomized to either TAU (4-12 sessions of supervised exercises for low back pain) or TAU plus SE (6-12 sessions). In total, 91 patients fulfilled the inclusion criteria and volunteered to participate in the study. Treatment effects were evaluated by self-report questionnaires comparing baseline measures with 12-month follow-up measures. Results: The additional SE intervention significantly reduced the number of PTSD symptoms compared with TAU alone, corresponding to a large effect size. Also, fear of movement was significantly reduced (moderate effect size). Both groups achieved a large reduction in pain-catastrophizing, disability and pain. Conclusions: A brief additional SE intervention was found to have a significant effect on PTSD and fear of movement compared to TAU alone. However, the overall effect of SE was less than expected and the clinical importance of the effects can be questioned.

Cerebrospinal Fluid Chemokine (C-C Motif) Ligand 2 Is an Early-Response Biomarker for Blast-Overpressure-Wave-Induced Neurotrauma in Rats

Chemokines and their receptors are of great interest within the milieu of immune responses elicited in the central nervous system in response to trauma. Chemokine (C-C motif)) ligand 2 (CCL2), which is also known as monocyte chemotactic protein-1, has been implicated in the pathogenesis of traumatic brain injury (TBI), brain ischemia, Alzheimer's disease, and other neurodegenerative diseases. In this study, we investigated the time course of CCL2 accumulation in cerebrospinal fluid (CSF) after exposures to single and repeated blast overpressures of varied intensities along with the neuropathological changes and motor deficits resulting from these blast conditions. Significantly increased concentrations of CCL2 in CSF were evident by 1 h of blast exposure and persisted over 24 h with peak levels measured at 6 h post-injury. The increased levels of CCL2 in CSF corresponded with both the number and intensities of blast overpressure and were also commensurate with the extent of neuromotor impairment and neuropathological abnormalities resulting from these exposures. CCL2 levels in CSF and plasma were tightly correlated with levels of CCL2 messenger RNA in cerebellum, the brain region most consistently neuropathologically disrupted by blast. In view of the roles of CCL2 that have been implicated in multiple neurodegenerative disorders, it is likely that the sustained high levels of CCL2 and the increased expression of its main receptor, CCR2, in the brain after blast may similarly contribute to neurodegenerative processes after blast exposure. In addition, the markedly elevated concentration of CCL2 in CSF might be a candidate early-response biomarker for diagnosis and prognosis of blast-induced TBI.

Pain in an era of armed conflicts: Prevention and treatment for warfighters and civilian casualties

Chronic pain is a common squealae of military- and terror-related injuries. While its pathophysiology has not yet been fully elucidated, it may be potentially related to premorbid neuropsychobiological status, as well as to the type of injury and to the neural alterations that it may evoke. Accordingly, optimized approaches for wounded individuals should integrate primary, secondary and tertiary prevention in the form of thorough evaluation of risk factors along with specific interventions to contravene and mitigate the ensuing chronicity. Thus, Premorbid Events phase may encompass assessments of psychological and neurobiological vulnerability factors in conjunction with fostering preparedness and resilience in both military and civilian populations at risk. Injuries per se phase calls for immediate treatment of acute pain in the field by pharmacological agents that spare and even enhance coping and adaptive capabilities. The key objective of the Post Injury Events is to prevent and/or reverse maladaptive peripheral- and central neural system's processes that mediate transformation of acute to chronic pain and to incorporate timely interventions for concomitant mental health problems including post-traumatic stress disorder and addiction We suggest that the proposed continuum of care may avert more disability and suffering than the currently employed less integrated strategies. While the requirements of the armed forces present a pressing need for this integrated continuum and a framework in which it can be most readily implemented, this approach may be also instrumental for the care of civilian casualties.

Longitudinal Associations Among Pain, Posttraumatic Stress Disorder Symptoms, and Stress Appraisals

Comorbidity of posttraumatic stress disorder (PTSD) and pain is well documented, but the mechanisms underlying their comorbidity are not well understood. Cross-lagged regression models were estimated with 3 waves of longitudinal data to examine the reciprocal associations between PTSD symptom severity, as measured by the Clinician-Administered PTSD Scale (CAPS), and pain, as measured by a brief self-report measure of pain called the PEG (pain intensity [P], interference with enjoyment of life [E], and interference with general activity [G]). We evaluated stress appraisals as a mediator of these associations in a sample of low-income, underserved patients with PTSD (N = 355) at federally qualified health centers in a northeastern metropolitan area. Increases in PTSD symptom severity between baseline and 6-month and 6- and 12-month assessments were independently predicted by higher levels of pain (β = .14 for both lags) and appraisals of life stress as uncontrollable (β = .15 for both lags). Stress appraisals, however, did not mediate these associations, and PTSD symptom severity did not predict change in pain. Thus, the results did not support the role of stress appraisals as a mechanism underlying the associations between pain and PTSD.

Rutin Acid Ameliorates Neural Apoptosis Induced by Traumatic Brain Injury via Mitochondrial Pathways in Mice

Rutin reportedly conveys many beneficial effects, including neuroprotection in brain injury. However, the mechanisms underlying these effects are still not well understood. This study investigates the effect of rutin on potential mechanisms for neuroprotective effects, using the weight-drop model of traumatic brain injury (TBI) in male mice treated either with rutin or a vehicle via intraperitoneal injection 30 min after TBI. After euthanasia and 24 h after TBI, all mice were examined by tests, including neurologic scores, blood-brain barrier permeability, brain water content and neuronal cell death in the cerebral cortex. Results indicate that the levels of cytochrome c, malondialdehyde (MDA) and superoxide dismutase (SOD) were restored by rutin treatment. Rutin treatment resulted in the downregulation of caspase-3 expression in a reduced number of positive cells under terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, and also the improved survival of neurons. Furthermore, pretreatment levels of MDA were restored, while Bcl-2-associated X protein translocation to mitochondria and cytochrome c release into cytosol were reduced by rutin treatment. Our results demonstrate that rutin improves neurological outcome by protecting neural cells against apoptosis via mechanisms that involve the mitochondria following TBI.