Pain and Posttraumatic Stress Symptom Clusters: A Cross-Lagged Study

The relationship between traumatic exposure and pain perception in children: the moderating role of posttraumatic symptoms

ABSTRACT

Adverse childhood experiences (ACEs) affect approximately half of all children worldwide. These experiences have been linked to increased pain sensitivity in adulthood and a higher likelihood of developing severe chronic pain. However, most studies have assessed the effects of ACEs retrospectively, long after they occurred, leaving room for other factors to influence the observed outcomes. We investigated, for the first time, the association between ACEs and concurrent pain perception among young children who live in a conflict zone and are consistently exposed to potentially traumatic experiences. Participants were 60 elementary school children (ages 8-11 years) living in conflict regions (n = 39) or nonconflict regions (n = 21). Posttraumatic stress symptom (PTSS) severity, traumatic exposure, pressure pain threshold (PPT), and mechanical detection threshold (MDT) were measured. Trauma-exposed children had significantly lower PPT than did controls, but MDT was similar across groups. Pressure pain threshold correlated positively with proximity to the conflict zone and inversely with traumatic exposure magnitude and PTSS severity. In addition, PTSSs moderated the relationship between repeated traumatic exposure and PPT. Children with higher PTSS severity displayed pain hypersensitivity regardless of their traumatic exposure level, whereas in children with lower PTSS severity, greater traumatic exposure correlated with pain hypersensitivity. The results suggest that ACEs among children lead to concurrent pain hypersensitivity and distress and may put them at elevated risk of chronic pain early in life. In addition, our findings emphasize the need for identifying children with various PTSS levels to provide tailored interventions and mitigate the long-term negative effects of ACEs.

Expectation of pain and relief: A dynamical model of the neural basis for pain-trauma co-morbidity

Posttraumatic Stress Disorder (PTSD) is highly co-morbid with chronic pain conditions. When present, PTSD significantly worsens chronic pain outcomes. Likewise, pain contributes to a more severe PTSD as evidenced by greater disability, more frequent use of harmful opioid analgesics and increased pain severity. The biomechanism behind this comorbidity is incompletely understood, however recent work strongly supports the widely-accepted role of expectation, in the entanglement of chronic pain and trauma symptoms. This work has shown that those with trauma have a maladaptive brain response while expecting stress and pain, whereas those with chronic pain may have a notable impairment in brain response while expecting pain relief. This dynamical expectation model of the interaction between neural systems underlying expectation of pain onset (traumatic stress) and pain offset (chronic pain) is biologically viable and may provide a biomechanistic insight into pain-trauma comorbidity. These predictive mechanisms work through interoceptive pathways in the brain critically the insula cortex. Here we highlight how the neural expectation-related mechanisms augment the existing models of pain and trauma to better understand the dynamics of pain and trauma comorbidity. These ideas will point to targeted complementary clinical approaches, based on mechanistically separable neural biophenotypes for the entanglement of chronic pain and trauma symptoms.

Stepped collaborative care for pain and posttraumatic stress disorder after major trauma: a randomized controlled feasibility trial

PURPOSE

To examine feasibility and acceptability of providing stepped collaborative care case management targeting posttraumatic stress disorder (PTSD) and pain symptoms after major traumatic injury.

MATERIALS AND METHODS

Participants were major trauma survivors in Victoria, Australia, at risk of persistent pain or PTSD with high baseline symptoms. Participants were block-randomized, stratified by compensation-status, to the usual care (n = 15) or intervention (n = 17) group (46% of eligible patients). The intervention was adapted from existing stepped collaborative care interventions with input from interdisciplinary experts and people with lived experience in trauma and disability. The proactive case management intervention targeted PTSD and pain management for 6-months using motivational interviewing, cognitive behavioral therapy strategies, and collaborative care. Qualitative interviews explored intervention acceptability.

RESULTS

Intervention participants received a median of 7 h case manager contact and reported that they valued the supportive and non-judgmental listening, and timely access to effective strategies, resources, and treatments post-injury from the case manager. Participants reported few disadvantages from participation, and positive impacts on symptoms and recovery outcomes consistent with the reduction in PTSD and pain symptoms measured at 1-, 3- and 6-months.

CONCLUSIONS

Stepped collaborative care was low-cost, feasible, and acceptable to people at risk of PTSD or pain after major trauma.IMPLICATIONS FOR REHABILITATIONAfter hospitalization for injury, people can experience difficulty accessing timely support to manage posttraumatic stress, pain and other concerns.Stepped case management-based interventions that provide individualized support and collaborative care have reduced posttraumatic stress symptom severity for patients admitted to American trauma centers.We showed that this model of care could be adapted to target pain and mental health in the trauma system in Victoria, Australia.The intervention was low cost, acceptable and highly valued by most participants who perceived that it helped them use strategies to better manage post-traumatic symptoms, and to access clinicians and treatments relevant to their needs.

Predicting chronic pain two years following a spinal cord injury: Longitudinal study on the reciprocal role of acute pain and PTSD symptoms

OBJECTIVES

To examine a) the development of PTSD symptoms and pain over five months post-spinal cord injury (SCI); b) the directional effects of PTSD symptoms and pain across five months post-SCI; and c) the prediction of chronic pain two-years post-SCI by PTSD symptoms and pain severity in the first five months post-SCI.

STUDY DESIGN

Two-year longitudinal study.

SETTING

: Individuals with an SCI admitted to the Department of Neurological Rehabilitation (N = 65).

OUTCOME MEASURES

: PTSD symptoms and pain were evaluated at 1.5 months (T1), three months (T2), and five months (T3) post-SCI. Chronic pain was evaluated at 24 months post-SCI (follow-up).

RESULTS

Seventy-five percent of participants reported chronic pain at follow-up. Pain severity at T1 and T2 predicted PTSD symptoms at T2 and T3, respectively. PTSD symptoms at T2 predicted pain severity at T3. Individuals with chronic pain at follow-up had reported more PTSD symptoms at T1, T2, and T3 than those without pain. A multivariate model yielded two significant indirect paths: a) PTSD symptoms at T1 predicted chronic pain severity at follow-up through PTSD symptoms at T2 and T3, and b) pain severity at T1 predicted chronic pain severity at follow-up through pain severity at T2 and T3.

CONCLUSIONS

Both pain and PTSD in the acute post-SCI phase are markers for chronic pain two years later. PTSD and chronic pain exhibit a complex, reciprocal relationship across time that contributes to pain chronicity. Identifying individuals at risk and implementing interventions targeting both pain and PTSD symptoms during the acute phase may prevent their chronification.

Are We Any Closer to Understanding How Chronic Pain Develops? A Systematic Search and Critical Narrative Review of Existing Chronic Pain Vulnerability Models

Identifying biopsychosocial factors underlying chronic pain vulnerability is essential for the design of preventative efforts. Multiple chronic pain vulnerability models exist, however, there is a lack of comprehensive evaluation of these models in the literature, potentially due to the lack of guidelines that specify the criteria by which these types of work should be assessed. In this work, we created evaluation criteria (based on the general goals of conceptual models), and we then used them to critically review the chronic pain vulnerability models available in the current peer-reviewed literature (identified through a systematic search). Particularly, we evaluated the models on the basis of conceptual clarity/specificity of measures, depth of description of aetiological and mechanistic factors, use of a whole system approach, and quality of the evidence associated with the models. We found nine conceptual models that have been explored in detail (eg, fear avoidance model, diathesis-stress model). These models excel at clarity and are supported mostly by self-report evidence of a psychological nature (anxiety sensitivity, pain catastrophizing, etc.), but provide little explanation of mechanistic and aetiological factors. In the future, models could be improved by complementing them with proposals from other models and exploring potential causal factors and mechanisms maintaining the condition. This task could be carried out through prospective cohort studies, and computational approaches, amongst others.

Role of burn severity and posttraumatic stress symptoms in the co-occurrence of itch and neuropathic pain after burns: A longitudinal study

Itch and pain are common after burns. Neuropathic mechanisms may underlie both modalities but remain not well-understood. This study aims to prospectively document neuropathic pain symptoms and to identify potential itch symptom profiles that differ regarding duration and co-occurrence with neuropathic pain which may inform underlying pathophysiological mechanisms and respond to different treatments. Adult burn survivors (n = 192) self-reported itch and neuropathic pain at 2 weeks post-discharge, 3, 6, 12, and 18 months post-burn. Based on the presence of itch and pain symptoms over time, participants were allocated to one itch profile: transient itch/pain, chronic itch, or chronic itch & pain. Profiles were compared on itch intensity over time using General Linear Modeling. Age, gender, burn severity, posttraumatic stress (PTS) symptoms and baseline itch intensity were examined as potential predictors of the profiles in a Multi-nominal regression analysis. Neuropathic pain occurred in 54% after discharge which decreased to 24% 18 months later. Itch intensity was highest in the chronic itch & pain profile. Compared to the transient itch profile, the chronic itch & pain profile was associated with higher burn severity and more PTS symptoms. Compared to the chronic itch profile, the chronic itch & pain profile was associated with more PTS symptoms. Findings suggest that biological and psycho-dermatological processes underlie both chronic neuropathic pain and itch processes in burn scars. Further research should elucidate the mechanisms underlying the different itch profiles, with specific focus on skin innervation and psychological factors.

The role of pain and socioenvironmental factors on posttraumatic stress disorder symptoms in traumatically injured adults: A 1-year prospective study

Approximately 20% of individuals who experience a traumatic injury will subsequently develop posttraumatic stress disorder (PTSD). Physical pain following traumatic injury has received increasing attention as both a distinct, functionally debilitating disorder and a comorbid symptom related to PTSD. Studies have demonstrated that both clinician-assessed injury severity and patient pain ratings can be important predictors of nonremitting PTSD; however, few have examined pain and PTSD alongside socioenvironmental factors. We postulated that both area- and individual-level socioeconomic circumstances and lifetime trauma history would be uniquely associated with PTSD symptoms and interact with the pain-PTSD association. To test these effects, pain and PTSD symptoms were assessed at four visits across a 1-year period in a sample of 219 traumatically injured participants recruited from a Level 1 trauma center. We used a hierarchal linear modeling approach to evaluate whether (a) patient-reported pain ratings were a better predictor of PTSD than clinician-assessed injury severity scores and (b) socioenvironmental factors, specifically neighborhood socioeconomic disadvantage, individual income, and lifetime trauma history, influenced the pain-PTSD association. Results demonstrated associations between patient-reported pain ratings, but not clinician-assessed injury severity scores, and PTSD symptoms, R^{2( fvm )} = .65. There was a significant interaction between neighborhood socioeconomic disadvantage and pain such that higher disadvantage decreased the strength of the pain-PTSD association but only among White participants, R^{2( fvm )} = .69. Future directions include testing this question in a larger, more diverse sample of trauma survivors (e.g., geographically diverse) and examining factors that may alleviate both pain and PTSD symptoms.