Dysfunctional Pain Modulation in Torture Survivors: The Mediating Effect of PTSD

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.

Mediators of the association between childhood trauma and pain sensitivity in adulthood: a Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network analysis

ABSTRACT

Urologic chronic pelvic pain syndrome (UCPPS) is a complex, debilitating condition in which patients often report nonpelvic pain in addition to localized pelvic pain. Understanding differential predictors of pelvic pain only vs widespread pain may provide novel pathways for intervention. This study leveraged baseline data from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network's Symptom Pattern Study to investigate the impact of childhood sexual and nonsexual violent trauma on pelvic and nonpelvic pain sensitivity among adult patients with UCPPS, as well as potential mediators of this association. Study participants who met inclusion criteria for UCPPS completed questionnaires assessing childhood and recent trauma, affective distress, cognitive dysfunction, and generalized sensory sensitivity. Experimental pain sensitivity was also evaluated using standardized pressure pain applied to the pubic region and the arm. Bivariate analyses showed that childhood violent trauma was associated with more nonviolent childhood trauma, more recent trauma, poorer adult functioning, and greater pain sensitivity at the pubic region, but not pain sensitivity at the arm. Path analysis suggested that childhood violent trauma was indirectly associated with pain sensitivity at both sites and that this indirect association was primarily mediated by generalized sensory sensitivity. More experiences of recent trauma also contributed to these indirect effects. The findings suggest that, among participants with UCPPS, childhood violent trauma may be associated with heightened pain sensitivity to the extent that trauma history is associated with a subsequent increase in generalized sensory sensitivity.

A qualitative study of equine-assisted therapy for Israeli military and police veterans with PTSD-impact on self-regulation, bonding and hope

Equine-assisted therapy (EAT) is an increasingly popular form of treatment for people suffering from post-traumatic stress disorder (PTSD) who, for one reason or another, find psychotherapy and other traditional treatment approaches unsuitable or unhelpful. However, the concomitant growth of research in the field is yet to engage with key factors relating to EAT; specifically, there are few studies considering the phenomenological perspective of patients, and the embodied knowledge deriving from the lived experience of PTSD patients who participated in EAT-based intervention programmes. Based on a qualitative-phenomenological study, interviews were conducted with 12 PTSD patients who had completed an EAT-based intervention programme. From these, three main themes characterising the meanings they gave to participation in an EAT-based treatment programme were identified: the ability to relax (self-regulation); establishing a relationship (bonding) and transformation and hope for the future. The findings of this study point to a process whereby participation in an EAT-based treatment programme facilitates the ability to cope with PTSD symptoms in a way that bridges the patient's emotional, social and spiritual-existential dimensions. The findings suggest that EAT can contribute to the healing process of veterans suffering from PTSD.

Altered physical pain processing in different psychiatric conditions

Several reports indicate either increased or decreased pain sensitivity associated with psychiatric disorders. Chronic pain is highly prevalent in many of these conditions. We reviewed the literature regarding experimental pain sensitivity in patients with major depression, bipolar disorder, posttraumatic stress disorder (PTSD), generalized anxiety disorder, panic disorder, obsessive-compulsive disorder and schizophrenia. Electronic searches were performed to identify studies comparing experimental pain in patients with these conditions and controls. Across 31 depression studies, reduced pain threshold was noted except for ischemic stimuli, where increased pain tolerance and elevated sensitivity to ischemic pain was observed. A more pervasive pattern of low pain sensitivity was found across 20 schizophrenia studies. The majority of PTSD studies (n = 20) showed no significant differences compared with controls. The limited number of bipolar disorder (n = 4) and anxiety (n = 9) studies precluded identification of clear trends. Wide data variability was observed. Awareness of psychiatric patients' pain perception abnormalities is needed for active screening and addressing physical comorbidities, in order to enhance quality of life, life expectancy and mental health.

Uncovering re-traumatization experiences of torture survivors in somatic health care: A qualitative systematic review

Little research has focused on torture survivors' re-traumatization experiences in health and hospital units that treat somatic diseases, though any medical procedure can re-traumatize survivors. This study's purpose was to summarize qualitative research evidence on torture survivors' somatic healthcare experiences and to identify "triggers" or "reminders" that can lead to re-traumatization. The study's search strategies identified 6,326 citations and eight studies, comprising data from 290 participants, exploring encounters with healthcare providers from torture survivors' perspectives, which were included in the present research. Dallam's Healthcare Retraumatization Model was used as a framework for data extraction and analysis. Five main themes were elicited from the findings: (1) invisibility, silence, and mistrust; (2) healthcare providers' attitudes and a lack of perceived quality in healthcare; (3) disempowerment; (4) avoidance; and (5) satisfaction and gratitude. An analysis of the study's findings revealed that torture survivors do not receive adequate healthcare and may experience challenges during treatment that can result in re-traumatization. The findings of this literature review provide a basis for understanding the difficulties that survivors experience in receiving somatic healthcare, as well as an explanation of the re-traumatization process.

Pain perception and processing in individuals with posttraumatic stress disorder: a systematic review with meta-analysis

Supplemental Digital Content is Available in the Text.

Posttraumatic stress disorder encompasses latent subgroups of individuals with qualitative differences in pain perception.

Posttraumatic stress disorder (PTSD) is a known risk factor for the development of chronic pain conditions, and almost 1 in 5 individuals with chronic pain fulfills the criteria for PTSD. However, the relationship between PTSD and pain is poorly understood and studies on pain perception in patients with PTSD show inconsistent results suggesting that different sensory profiles exist among individuals with PTSD. Here, we (1) systematically summarize the current literature on experimentally evoked pain perception in patients with PTSD compared to subjects without PTSD, and (2) assess whether the nature of the traumatic event is associated with different patterns in pain perception. The main outcome measures were pain threshold, pain tolerance, and pain intensity ratings as well as measures of temporal summation of pain and conditioned pain modulation. A systematic search of MEDLINE, EMBASE, Web of Science, PsycINFO, and CINAHL identified 21 studies for the meta-analysis, including 422 individuals with PTSD and 496 PTSD-free controls. No main effect of PTSD on any outcome measure was found. However, stratification according to the nature of trauma revealed significant differences of small to medium effect sizes. Combat-related PTSD was associated with increased pain thresholds, whereas accident-related PTSD was associated with decreased pain thresholds. No clear relationship between PTSD and experimentally evoked pain perception exists. The type of trauma may affect pain thresholds differently indicating the presence of different subgroups with qualitative differences in pain processing.

Punishing the Self: Post-Traumatic Guilt Mediates the Link Between Trauma and Deficient Pain Modulation

Trauma survivors may suffer from post-traumatic stress disorder (PTSD), elevated post-traumatic guilt (PG), and alterations in the pain system. However, the association between PG and alterations in pain perception and modulation among trauma survivors has not been established, nor has the possible underlying role of PG. This longitudinal study investigated: 1) the unique contribution of PG in predicting pain perception and modulation, while controlling for PTSD symptoms; and 2) the mediating role of PG in explaining pain perception and modulation among torture survivors, above and beyond PTSD symptoms. Participants were 59 torture survivors and 44 age-matched controls. PG and PTSD symptoms were assessed in 2003 (T1). Heat-pain threshold, heat-pain tolerance, temporal summation of pain (TSP), and conditioned pain modulation (CPM) were measured 5 years later (T2). Torture survivors had elevated PG and PTSD symptoms, enhanced TSP, and reduced CPM, compared to controls. While PTSD predicted reduced pain tolerance and CPM, PG predicted increased pain tolerance. Moreover, PG mediated the associations between torture and (increased) pain threshold, pain tolerance, and TSP. It appears that PTSD and PG induce opposite effects on the pain modulation capacity of torture survivors, a dichotomy that may explain paradoxical pain responses among trauma survivors, as discussed. PERSPECTIVE: This longitudinal study sheds light on the possible mechanisms underlying variations in pain perception and modulation among trauma survivors. PTSD and PG each mediated opposing pain modulation profiles, suggesting that individual responses to trauma, rather than the trauma itself, influence pain responses.

The management of post-traumatic stress disorder and associated pain and sleep disturbance in refugees

More than 68 million people worldwide have been forcibly displaced and one-third of these are refugees. This article offers an overview of the current literature and reviews the epidemiology and evidence-based psychological and pharmacological management of post-traumatic stress disorder (PTSD), sleep disturbance and pain in refugees and asylum seekers. It also considers the relationship between sleep disturbance and PTSD and explores concepts of pain in relation to physical and psychological trauma and distress. During diagnosis, clinicians must be aware of ethnic variation in the somatic expression of distress. Treatments for PTSD, pain and sleep disturbance among refugees and asylum seekers are essentially the same as those used in the general population, but treatment strategies must allow for cultural and contextual factors, including language barriers, loss of freedom and threat of repatriation.

LEARNING OBJECTIVES

After reading this article you will be able to: •

DECLARATION OF INTEREST

None.

Subliminal (latent) processing of pain and its evolution to conscious awareness

By unconscious or covert processing of pain we refer to nascent interactions that affect the eventual deliverance of pain awareness. Thus, internal processes (viz., repeated nociceptive events, inflammatory kindling, reorganization of brain networks, genetic) or external processes (viz., environment, socioeconomic levels, modulation of epigenetic status) contribute to enhancing or inhibiting the presentation of pain awareness. Here we put forward the notion that for many patients, ongoing sub-conscious changes in brain function are significant players in the eventual manifestation of chronic pain. In this review, we provide clinical examples of nascent or what we term pre-pain processes and the neurobiological mechanisms of how these changes may contribute to pain, but also potential opportunities to define the process for early therapeutic interventions.

Repeated Exposure to Experimental Pain Differentiates Combat Traumatic Brain Injury with and without Post-Traumatic Stress Disorder

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are highly comorbid conditions that often co-occur with chronic pain. We have shown that women with PTSD subsequent to intimate partner violence show attenuated brain response to repeated experimental pain that was related to symptoms of avoidance. The aim of this study was to extend our past findings to males with combat trauma and to examine brain response to experimental pain in men with and without PTSD who sustained mTBI during combat. Seventy male veterans performed an experimental pain paradigm during functional magnetic resonance imaging fMRI. Of the 70 total subjects, 46 self-reported a history of mTBI during combat (46 of 70). Of those with mTBI, 26 also met criteria for PTSD (26 of 46). As in our previous study, we examined change in brain activity to repeated heat pain with linear mixed-effects modeling for group by administration interaction effects. We observed a significant group by administration interaction to repeated heat pain within insular, frontal, and parietal cortices, such that the control group showed increased activation over time, whereas mTBI groups (mTBI-only, mTBI + PTSD) showed decreased activation within bilateral anterior insulas (AIs) between administrations. Importantly, change in the right AI response was inversely correlated with avoidance symptoms, but only in those with comorbid mTBI + PTSD. Further, in the comorbid group, greater AI attenuation was associated with decreased connectivity with anterior cingulate (ACC). The current study provides further evidence that repeated exposure to brief painful stimuli results in attenuation of insula activation over time in traumatized individuals. Further, in PTSD, AI shows greatest attenuation in those with the highest level of avoidance-a finding that was replicated across diverse samples. Thus, this mechanism may be a generalized mechanism of maladaptive response to experimental pain in those with significant trauma.

Interventions for treating persistent pain in survivors of torture

BACKGROUND

Persistent (chronic) pain is a frequent complaint in survivors of torture, particularly but not exclusively pain in the musculoskeletal system. Torture survivors may have no access to health care; where they do, they may not be recognised when they present, and the care available often falls short of their needs. There is a tendency in state and non-governmental organisations' services to focus on mental health, with poor understanding of persistent pain, while survivors may have many other legal, welfare, and social problems that take precedence over health care.

OBJECTIVES

To assess the efficacy of interventions for treating persistent pain and associated problems in survivors of torture.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) published in any language in CENTRAL, MEDLINE, Embase, Web of Science, CINAHL, LILACS, and PsycINFO, from database inception to 1 February 2017. We also searched trials registers and grey literature databases.

SELECTION CRITERIA

RCTs of interventions of any type (medical, physical, psychological) compared with any alternative intervention or no intervention, and with a pain outcome. Studies needed to have at least 10 participants in each arm for inclusion.

DATA COLLECTION AND ANALYSIS

We identified 3578 titles in total after deduplication; we selected 24 full papers to assess for eligibility. We requested data from two completed trials without published results.We used standard methodological procedures expected by Cochrane. We assessed risk of bias and extracted data. We calculated standardised mean difference (SMD) and effect sizes with 95% confidence intervals (CI). We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Three small published studies (88 participants) met the inclusion criteria, but one had been retracted from publication because of ethical problems concerned with confidentiality and financial irregularities. Since these did not affect the data, the study was retained in this review. Despite the search including any intervention, only two types were represented in the eligible studies: two trials used cognitive behavioural therapy (CBT) with biofeedback versus waiting list on unspecified persistent pain (58 participants completed treatment), and one examined the effect of complex manual therapy versus self-treatment on low back pain (30 participants completed treatment). Excluded studies were largely either not RCTs or did not report pain as an outcome.There was no difference for the outcome of pain relief at the end of treatment between CBT and waiting list (two trials, 58 participants; SMD -0.05, 95% CI -1.23 to 1.12) (very low quality evidence); one of these reported a three-month follow-up with no difference between intervention and comparison (28 participants; SMD -0.03, 95% CI -0.28 to 0.23) (very low quality evidence). The manual therapy trial also reported no difference between complex manual therapy and self-treatment (30 participants; SMD -0.48, 95% CI -9.95 to 0.35) (very low quality evidence). Two studies reported dropouts, one with partial information on reasons; none of the studies reported adverse effects.There was no information from any study on the outcomes of use of analgesics or quality of life.Reduction in disability showed no difference at the end of treatment between CBT and waiting list (two trials, 57 participants; SMD -0.39, 95% CI -1.17 to 0.39) (very low quality evidence); one of these reported a three-month follow-up with no difference between intervention and comparison (28 participants; SMD 0, 95% CI -0.74 to 0.74) (very low quality evidence). The manual therapy trial reported superiority of complex manual therapy over self-treatment for reducing disability (30 participants; SMD -1.10, 95% CI - 1.88 to -0.33) (very low quality evidence).Reduction in distress showed no difference at the end of treatment between CBT and waiting list (two trials, 58 participants; SMD 0.07, 95% CI -0.46 to 0.60) (very low quality evidence); one of these reported a three-month follow-up with no difference between intervention and comparison (28 participants; SMD -0.24, 95% CI -0.50 to 0.99) (very low quality evidence). The manual therapy trial reported superiority of complex manual therapy over self-treatment for reducing distress (30 participants; SMD -1.26, 95% CI - 2.06 to -0.47) (very low quality evidence).The risk of bias was considered high given the small number of trials, small size of trials, and the likelihood that each was underpowered for the comparisons it reported. We primarily downgraded the quality of the evidence due to small numbers in trials, lack of intention-to-treat analyses, high unaccounted dropout, lack of detail on study methods, and CIs around effect sizes that included no effect, benefit, and harm.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the use of any intervention for persistent pain in survivors of torture.

Validation of the Greek Version of the Fibromyalgia Rapid Screening Tool

BACKGROUND AND AIM

The Fibromyalgia Rapid Screening Tool (FiRST) is a brief, simple, and straightforward self-administered questionnaire that was developed by Perrot et al. for the detection of fibromyalgia syndrome in patients with diffuse chronic pain. The aim of our study was to develop and validate the Greek version of FiRST.

METHODS

The study was set up as a prospective observational study. The original French version of FiRST was adapted into Greek using forward and backward translation. Patients with chronic diffuse pain with a clinical diagnosis of fibromyalgia and osteoarthritis based on the criteria of the American College of Rheumatology were invited to participate to the study.

RESULTS

Of the 101 patients who met our inclusion criteria, 42 were diagnosed with fibromyalgia and 59 with osteoarthritis. The 2 groups did not differ significantly regarding gender and pain characteristics (duration, intensity). Cronbach's alpha coefficient was 0.79. Receiver operating characteristic analysis showed an area under the curve of 89% (95% confidence interval = 83 to 95%; SE: 0.032, P < 0.001). At a cutoff score of ≥ 5, FiRST showed a sensitivity of 86%, a specificity of 83%, a positive predictive value of 78%, and a negative predictive value of 89%. The intraclass coefficient for the test-retest reliability was 0.96.

CONCLUSION

The Greek version of FiRST is a valid screening tool for fibromyalgia in daily practice.

Post-traumatic stress disorder moderates the relationship between trauma exposure and chronic pain

Background: Trauma exposure and post-traumatic stress disorder (PTSD) are risk factors for chronic pain. Objective: This study investigated how exposure to intentional and non-intentional traumatic events and PTSD are related to pain severity and outcome of treatment in chronic pain patients. Methods: We assessed exposure to potentially traumatizing events, psychiatric diagnosis with structured clinical interview, and pain severity in 63 patients at a secondary multidisciplinary pain clinic at the beginning of treatment, and assessed level of pain at follow up. Exposure to potentially traumatizing events and PTSD were regressed on pain severity at the initial session and at follow up in a set of multiple regression analysis. Results: The participants reported exposure to an average of four potentially traumatizing events, and 32% had PTSD. Exposure to intentional traumatic events and PTSD were significantly associated with more severe pain, and PTSD significantly moderated the relationship between trauma exposure and pain (all p < .05). The treatment programme reduced pain moderately, an effect that was unrelated to trauma exposure and PTSD. Conclusions: Trauma exposure is related to chronic pain in the same pattern as to mental disorders, with intentional trauma being most strongly related to pain severity. PTSD moderated the relationship between trauma exposure and pain. While pain patients with PTSD initially report more pain, they responded equally to specialist pain treatment as persons without PTSD.