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Background: Studies assessing athletes' pain sensitivity yield inconsistent data, which demonstrate either increased pain threshold and tolerance in athletes than controls or similar thresholds. This inconsistency may result from the variability in the type of sport practiced by the athletes and its effect on pain perception. For example, endurance athletes perform continuous intense exercise for prolonged durations, whereas strength athletes perform short bouts of extreme efforts. Consequently, endurance athletes may tolerate and modulate pain better than strength athletes. This hypothesis was tested by comparing pain perception of endurance athletes with that of strength athletes.Methods: Subjects were 19 endurance athletes (triathletes), 17 strength athletes (weightlifters and throwers) and 17 non-athlete controls. Quantitative measurements included heat-pain threshold, heat-pain tolerance, cold pressor pain ratings, temporal summation of pain (TSP) and conditioned pain modulation (CPM). Fear of pain and pain catastrophizing were also assessed.Results: The two athlete groups had lower pain ratings than non-athletes. However, strength athletes had higher heat-pain threshold than endurance athletes, whereas endurance athletes had higher heat-pain tolerance and stronger CPM than strength athletes and lower fear of pain levels. Longer training time correlated with TSP in endurance athletes but with CPM and heat-pain tolerance in strength athletes.Conclusions: Although athletes in general seem less responsive to noxious stimuli than non-athletes, the type of sport differentially affects pain perception; whereas endurance-based sport is associated with improved pain inhibition, strength-based sport is associated with reduced pain sensitivity. These characteristics may be considered when sport is recommended for pain management.Significance: This study shows that different sport types are associated with different characteristics of pain perception and modulation, as well as of thoughts towards pain. [ABSTRACT FROM AUTHOR]

Background and Objective: Pain assessment tools for cognitively impaired older people, unable to self-report pain, are commonly founded upon observation of pain behaviour, such as facial expressions, vocalizations and body movements. The scientific basis for claiming that body movements may indicate pain has not formerly been investigated in a systematic review. The objective was to explore research evidence for body movements being pain indicators in older people with cognitive impairment.Data Bases and Data Treatment: MEDLINE, EMBASE, CINAHL, PsycINFO and the Cochrane Library were searched systematically. Two researchers independently identified and consented on studies to be included. PRISMA statement for reporting systematic reviews was followed. Mixed Methods Appraisal Tool was used for critical evaluation of study quality.Results: A total of 2,096 records from the literature searches were identified, and 17 quantitative and eight qualitative studies were included in the review, the studies mainly related to older people with dementia. Quality scores ranged from 50% to 100%. We combined 62 items of body movements into 13 similar or synonymous items, and criteria for evidence were defined. Strong evidence was found for restlessness (agitation), rubbing, guarding, rigidity and physical aggression as the behaviours frequently responded (increased or decreased) to pain provoking activities, painful procedures and/or pain medication.Conclusions: Among 13 categories of body movements, we found five with strong and five with moderate evidence of validity. As few items were typically included in many studies reflecting criterion validity, all should be included in future studies of patients with different characteristics, location and duration of pain.Significance: Pain assessment tools for older people with cognitive impairment or dementia should include valid pain behaviour items. Our review shows strong scientific evidence for the following body movements indicating pain: restlessness (agitation), rubbing, guarding, rigidity and physical aggression. [ABSTRACT FROM AUTHOR]

Chronic post-traumatic headache (CPTHA), the most frequent complaint after traumatic brain injury (TBI), dramatically affects quality of life and function. Despite its high prevalence and persistence, the mechanism of CPTHA is poorly understood. This literature review aimed to analyze the results of studies assessing the characteristics and sensory profile of CPTHA in order to shed light on its possible underlying mechanisms. The search for English language articles published between 1960 and 2013 was conducted in MEDLINE, CINAHL, and PubMed. Studies assessing clinical features of headache after TBI as well as studies conducting quantitative somatosensory testing (QST) in individuals with CPTHA and in individuals suffering from other types of pain were included. Studies on animal models of pain following damage to peripheral tissues and to the peripheral and central nervous system were also included. The clinical features of CPTHA resembled those of primary headache, especially tension-type and migraine headache. Positive and negative signs were prevalent among individuals with CPTHA, in both the head and in other body regions, suggesting the presence of local (cranial) mechanical hypersensitivity, together with generalized thermal hypoesthesia and hypoalgesia. Evidence of dysfunctional pain modulation was also observed. Chronic post-traumatic headache can result from damage to intra- and pericranial tissues that caused chronic sensitization of these tissues. Alternatively, although not mutually exclusive, CPTHA might possibly be a form of central pain due to damage to brain structures involved in pain processing. These, other possibilities, as well as risk factors for CPTHA are discussed at length. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) is a debilitating neurological condition that often leads to central neuropathic pain (CNP). As the fundamental mechanism of CNP is not fully established, its management is one of the most challenging problems among people with SCI. To shed more light on CNP mechanisms, the aim of this cross-sectional study was to compare the brain structure between individuals with SCI and CNP and those without CNP by examining the gray matter (GM) volume and the white matter (WM) integrity. Fifty-two individuals with SCI—28 with CNP and 24 without CNP—underwent a magnetic resonance imaging (MRI) session, including a T1-weighted scan for voxel-based morphometry, and a diffusion-weighted imaging (DWI) scan for WM integrity analysis, as measured by fractional anisotropy (FA) and mean diffusivity (MD). We found significantly higher GM volume in individuals with CNP compared with pain-free individuals in the right superior (p < 0.0014) and middle temporal gyri (p < 0.0001). Moreover, individuals with CNP exhibited higher WM integrity in the splenium of the corpus callosum (p < 0.0001) and in the posterior cingulum (p < 0.0001), compared with pain-free individuals. The results suggest that the existence of CNP following SCI is associated with GM and WM structural abnormalities in regions involved in pain intensification and spread, and which may reflect maladaptive neural plasticity in CNP. [ABSTRACT FROM AUTHOR]

Central neuropathic pain (CNP) and musculoskeletal pain (MSP) are often comorbid with multiple sclerosis (MS), yet data on the emotional burden entailed by this comorbidity are very limited. We studied whether MS patients with CNP exhibited greater emotional burden and pain severity than those with MSP and whether this emotional burden was attributed to the MS, the chronic pain, or both. Participants were 125 MS patients (55 with CNP; 30 with MSP; 40 MS pain-free) and 30 healthy controls (HCs). Participants completed questionnaires assessing pain interference, pain catastrophizing, depression, anxiety, stress, hypervigilance, and chronic pain. Group comparisons and a two-step cluster analysis were performed, and the association between cluster membership and clinical group membership was evaluated. Chronic pain was stronger and more widespread in the CNP group than in the MSP group. Both pain groups had higher pain interference, pain catastrophizing, and stress compared to MS pain-free and HC groups. All MS groups had greater depression levels compared to HCs, and the CNP group had the highest anxiety level. The "high psychological distress" cluster comprised mainly participants with CNP (57%), and the "minimal psychological distress" cluster comprised mainly the MS pain-free and HC groups. In conclusion, CNP seems to induce greater emotional burden and pain severity than does MSP. Whereas depression may be attributed to MS, and anxiety to CNP, enhanced pain interference, catastrophizing, and stress may be attributed to the comorbidity of MS and chronic pain. Identifying these traits among MS patients and targeting them in management programs may contribute to more effective, individually based care. [ABSTRACT FROM AUTHOR]

Background: Consistent with the human tendency to anthropomorphize objects, events, and situations, individuals might ascribe human characteristics to physical symptoms and illnesses. This manuscript presents an examination of chronic pain personification in torture survivors. Specifically, it was hypothesized that torture survivors personify chronic pain as a torturing sensation. It was further hypothesized that PTSD mediates the effect of past torture on torturing pain personification.Methods: Fifty-nine Israeli ex-prisoners of war (ex-POWs), who experienced severe torture in captivity, and 44 matched controls completed self-administered questionnaires at 18, 30, and 35years post captivity.Results: Whereas ex-POWs exhibit higher torturing personification than controls, no differences were found in concrete description of chronic pain. PTSD trajectories were implicated in different levels of torturing personification. Finally, sequential mediation analysis revealed that PTSD at T2 and T3 mediated the association between torture and torturing personification.Conclusions: The findings suggest that trauma shapes the way individuals relate to and experience their bodily sensations. [ABSTRACT FROM AUTHOR]

The present study assesses the possible disruption effect of posttraumatic stress symptoms (PTSS) with regard to the protective role of attachment on pain, among ex-POWs. While secure attachment seems to serve as a buffer, decreasing the perception of pain, this function may be disrupted by PTSS. The study sample included 104 subjects who were combat veterans of the 1973 Yom Kippur War comprising of 60 male ex-prisoners of war (ex-POWs) and 44 comparable male combat veterans. Both attachment and pain were investigated experimentally in the laboratory and via questionnaires. We found that ex-POWs showed higher levels of clinical pain and attachment insecurities compared to controls. Moreover, attachment avoidance and soothing effect of attachment (SEA) were both associated with lower levels of clinical pain. Most importantly, PTSS moderated the associations between attachment and pain, as well as the mediation role of attachment between captivity and pain. The results imply that although attachment can be an important resource for coping with pain, it can be severely disrupted by PTSS among trauma survivors. [ABSTRACT FROM AUTHOR]

Anecdotes on the ability of individuals to continue to function under stressful conditions despite injuries causing excruciating pain suggest that acute stress may induce analgesia. However, studies exploring the effect of acute experimental stress on pain perception show inconsistent results, possibly due to methodological differences. Our aim was to systematically study the effect of acute stress on pain perception using static and dynamic, state-of-the-art pain measurements. Participants were 29 healthy men who underwent the measurement of heat-pain threshold, heat-pain intolerance, temporal summation of pain, and conditioned pain modulation (CPM). Testing was conducted before and during exposure to the Montreal Imaging Stress Task (MIST), inducing acute psychosocial stress. Stress levels were evaluated using perceived ratings of stress and anxiety, autonomic variables, and salivary cortisol. The MIST induced a significant stress reaction. Although pain threshold and pain intolerance were unaffected by stress, an increase in temporal summation of pain and a decrease in CPM were observed. These changes were significantly more robust among individuals with stronger reaction to stress (“high responders”), with a significant correlation between the perception of stress and the performance in the pain measurements. We conclude that acute psychosocial stress seems not to affect the sensitivity to pain, however, it significantly reduces the ability to modulate pain in a dose–response manner. Considering the diverse effects of stress in this and other studies, it appears that the type of stress and the magnitude of its appraisal determine its interactions with the pain system. [ABSTRACT FROM AUTHOR]

Introduction: Persistent post-traumatic headache remains a poorly understood clinical entity. Although there are currently no accepted therapies for persistent post-traumatic headache, its clinical symptoms, which primarily resemble those of migraine or tension-type headache, often serve to guide treatment. However, evidence-based justification for this treatment approach remains lacking given the paucity of knowledge regarding the characteristics of these two major persistent post-traumatic headache phenotypes and their etiology.Methods: We compared clinical features and quantitative sensory testing profiles between two distinct cohorts of persistent post-traumatic headache subjects that exhibited symptoms resembling either migraine (n = 15) or tension-type headache (n = 13), as well as to headache-free subjects that had suffered traumatic brain injury (n = 19), and to healthy controls (n = 10). We aimed to determine whether the two persistent post-traumatic headache subgroups could be discriminated based on additional clinical features, distinct quantitative sensory testing profiles, or the interaction of pain severity with the level of post-traumatic stress disorder.Results: Persistent post-traumatic headache subjects with migraine-like symptoms reported that bright light and focused attention aggravated their pain, while stress and nervousness were reported to aggravate the headache in subjects with tension-type headache-like symptoms. Quietness was better in alleviating migraine-like persistent post-traumatic headache, while anti-inflammatory medications provided better relief in tension-type headache-like persistent post-traumatic headache. The two persistent post-traumatic headache subgroups exhibited distinct quantitative sensory testing profiles with subjects exhibiting tension-type headache-like persistent post-traumatic headache displaying a more pronounced cephalic and extracephalic thermal hypoalgesia that was accompanied by cephalic mechanical hyperalgesia. While both persistent post-traumatic headache subgroups had high levels of post-traumatic stress disorder, there was a positive correlation with pain severity in subjects with tension-type headache-like symptoms, but a negative correlation in subjects with migraine-like symptoms.Conclusions: Distinct persistent post-traumatic headache symptoms and quantitative sensory testing profiles may be linked to different etiologies, potentially involving various levels of neuropathic and inflammatory pain, and if confirmed in a larger cohort, could be used to further characterize and differentiate between persistent post-traumatic headache subgroups in studies aimed to improve treatment. [ABSTRACT FROM AUTHOR]

Central neuropathic pain (CNP) after spinal cord injury (SCI) is debilitating and immensely impacts the individual. Central neuropathic pain is relatively resistant to treatment administered after it develops, perhaps owing to irreversible pathological processes. Although preemptive treatment may overcome this shortcoming, its administration necessitates screening patients with clinically relevant biomarkers that could predict CNP early post-SCI. The aim was to search for such biomarkers by measuring pronociceptive and for the first time, antinociceptive indices early post-SCI. Participants were 47 patients with acute SCI and 20 healthy controls. Pain adaptation, conditioned pain modulation (CPM), pain temporal summation, wind-up pain, and allodynia were measured above, at, and below the injury level, at 1.5 months after SCI. Healthy control were tested at corresponding regions. Spinal cord injury patients were monitored for CNP emergence and characteristics at 3 to 4, 6 to 7, and 24 months post-SCI. Central neuropathic pain prevalence was 57.4%. Central neuropathic pain severity, quality, and aggravating factors but not location somewhat changed over 24 months. Spinal cord injury patients who eventually developed CNP exhibited early, reduced at-level pain adaptation and CPM magnitudes than those who did not. The best predictor for CNP emergence at 3 to 4 and 7 to 8 months was at-level pain adaptation with odds ratios of 3.17 and 2.83, respectively (∼77% probability) and a cutoff value with 90% sensitivity. Allodynia and at-level CPM predicted CNP severity at 3 to 4 and 24 months, respectively. Reduced pain inhibition capacity precedes, and may lead to CNP. At-level pain adaptation is an early CNP biomarker with which individuals at risk can be identified to initiate preemptive treatment. [ABSTRACT FROM AUTHOR]

Background and objectives The prevalence of pain syndromes that affect the territories innervated by the trigeminal nerve, such as headaches, is one of the highest and ranks second only to low back pain. A potential mechanism underlying this high prevalence may be a relatively weak endogenous pain modulation of trigeminal pain. Here, we sought to systematically compare endogenous pain modulation capabilities in the trigeminal region to those of extra-trigeminal regions in healthy subjects. Methods Healthy, pain free subjects (n = 17) underwent a battery of quantitative sensory testing to assess endogenous pain inhibition and pain enhancement efficiencies within and outside the trigeminal innervated region. Measurements included conditioned pain modulation (CPM), temporal summation of pain (TSP) and spatial summation of pain (SSP). Results Testing configurations that included trigeminal-innervated body regions displayed significantly weaker CPM when compared to extra-trigeminal innervated areas. SSP magnitude was smaller in the ophthalmic trigeminal innervation when compared to other body regions. TSP magnitude was not different between the different body regions tested. Conclusions Our findings point to regional differences in endogenous pain inhibition and suggest that in otherwise healthy individuals, the trigeminal innervation is subjected to a weaker inhibitory pain control than other body regions. Such weaker endogenous pain control could play, at least in part, a role in mediating the high prevalence of trigeminal-related pain syndromes, including primary headaches and TMD pain. [ABSTRACT FROM AUTHOR]

Introduction: Exercise-induced hypoalgesia (EIHypo) among healthy individuals is well documented; however, the opposite effect of exercise, ie, exercise-induced hyperalgesia (EIHyper), has mainly been described in patients with chronic pain or after intense/painful exercise., Objectives: We investigated the extent to which EIHypo and/or EIHyper occur among healthy participants and whether these responses are associated with individuals' pain modulation capacity., Methods: Fifty-seven participants (mean age 29.20 ± 5.21 years) underwent testing of pressure pain threshold as an index of EIHypo/EIHyper: pain adaptation, offset analgesia (OA), and conditioned pain modulation as indices of pain modulation, prior to and immediately postsubmaximal isometric exercise (n = 40) or rest (n = 17, control group). Body awareness and exercise-evoked stress were also evaluated. Test-retest repeatability of the pain modulation indices was performed as well., Results: Twenty-four participants (60%) exhibited EIHypo, whereas 16 (40%) exhibited EIHyper. Pressure pain threshold did not change in the control group. Baseline (preexercise) OA efficacy predicted EIHypo/EIHyper. Furthermore, OA significantly decreased postexercise in the EIHyper subgroup and slightly increased in the EIHypo subgroup. Exercise-induced hypoalgesia was associated with magnitude of daily exercise while EIHyper was associated with increased exercise-evoked stress and body awareness., Conclusion: Submaximal isometric exercise can induce opposite effects on pain sensitivity among healthy participants-EIHypo or EIHyper. Descending pain inhibition pathways, and top-down influences over these pathways, seem to be involved in EIHypo/EIHyper effects. As such isometric exercise is often preferred in early stages of rehabilitation, preliminary screening individuals' vulnerability to this exercise is important; OA test may be used for this purpose., Competing Interests: The authors have no conflicts of interest to declare. Data available within the article. Supporting data available on request from the authors., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The International Association for the Study of Pain.)

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., (Copyright © 2024 International Association for the Study of Pain.)

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.

We studied whether there exist variations in pain responses between different intellectual and developmental disability (IDD) etiologies. Self-reports and facial expressions (Facial Action Coding System = FACS) were recorded during experimental pressure stimuli and compared among 31 individuals with IDD-13 with cerebral palsy (CP), nine with Down syndrome (DS), nine with unspecified origin (UIDD)-and among 15 typically developing controls (TDCs). The CP and DS groups had higher pain ratings and FACS scores compared to the UIDD and TDC groups, and steeper stimulus-response functions. The DS group exhibited the most diverse facial expressions. There were variations in the foci of facial expressions between groups. It appears that different IDD etiologies display distinct pain responses., (©AAIDD.)

Introduction: Intellectual and developmental disabilities (IDD) include conditions associated with physical, learning, language, behavioural, and/or intellectual impairment. Pain is a common and debilitating secondary condition compromising functional abilities and quality of life., Objectives: This article addresses scientific and clinical challenges in pain assessment and management in individuals with severe IDD., Methods: This Clinical Update aligns with the 2019 IASP Global Year Against Pain in the Vulnerable and selectively reviews recurring issues as well as the best available evidence and practice., Results: The past decade of pain research has involved the development of standardized assessment tools appropriate for individuals with severe IDD; however, there is little empirical evidence that pain is being better assessed or managed clinically. There is limited evidence available to inform effective pain management practices; therefore, treatment approaches are largely empiric and highly variable. This is problematic because individuals with IDD are at risk of developing drug-related side effects, and treatment approaches effective for other populations may exacerbate pain in IDD populations. Scientifically, we are especially challenged by biases in self-reported and proxy-reported pain scores, identifying valid outcome measures for treatment trials, being able to adequately power studies due to small sample sizes, and our inability to easily explore the underlying pain mechanisms due to compromised ability to self-report., Conclusion: Despite the critical challenges, new developments in research and knowledge translation activities in pain and IDD continue to emerge, and there are ongoing international collaborations., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Introduction: Intellectual and developmental disabilities (IDD) include conditions associated with physical, learning, language, behavioural, and/or intellectual impairment. Pain is a common and debilitating secondary condition compromising functional abilities and quality of life., Objectives: This article addresses scientific and clinical challenges in pain assessment and management in individuals with severe IDD., Methods: This Clinical Update aligns with the 2019 IASP Global Year Against Pain in the Vulnerable and selectively reviews recurring issues as well as the best available evidence and practice., Results: The past decade of pain research has involved the development of standardized assessment tools appropriate for individuals with severe IDD; however, there is little empirical evidence that pain is being better assessed or managed clinically. There is limited evidence available to inform effective pain management practices; therefore, treatment approaches are largely empiric and highly variable. This is problematic because individuals with IDD are at risk of developing drug-related side effects, and treatment approaches effective for other populations may exacerbate pain in IDD populations. Scientifically, we are especially challenged by biases in self-reported and proxy-reported pain scores, identifying valid outcome measures for treatment trials, being able to adequately power studies due to small sample sizes, and our inability to easily explore the underlying pain mechanisms due to compromised ability to self-report., Conclusion: Despite the critical challenges, new developments in research and knowledge translation activities in pain and IDD continue to emerge, and there are ongoing international collaborations., Competing Interests: The authors have no conflicts of interest to declare.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The International Association for the Study of Pain.)

Objective: Individuals exposed to trauma, especially those who develop posttraumatic stress disorder (PTSD), are at a higher risk of suffering from chronic pain as well as altered pain perception and modulation. However, the underlying mechanisms of these processes are yet to be established. Recent findings have indicated that trauma survivors tend to personify chronic pain that is developed after the exposure, in a way that resonates with the traumatic experience. The aim of this study was to test whether pain personification plays a significant role in explaining the long-term links between trauma, PTSD and pain., Methods: This study is part of a large-scale longitudinal study on ex-prisoners of war (ex-POWs) from the 1973 Yom-Kippur war, who were followed over 35 years after the war. Fifty-nine ex-POWs who were exposed to torture and 44 matched combatants were assessed for PTSD at 18, 30, and 35 post-war. Quantitative somatosensory testing of heat-pain threshold, pain tolerance, conditioned pain modulation (CPM), and temporal summation of pain (TSP), as well as torturing personification, were assessed at 35 years after the war., Results: Sequential mediation analyses revealed that the associations between torture and heat pain threshold, as well as pain tolerance were mediated by PTSD at several time-points (-1.43

Patients with radicular low back pain (radicular LBP, sciatica) frequently describe their pain as "shooting" or "radiating." The dictionary meaning of these words implies rapid movement, and indeed, many sufferers report feeling pain moving rapidly from the lower back or buttock into the leg. But, others do not. Moreover, the sensation of movement is paradoxical; it is neither predicted nor accounted for by current ideas about the pathophysiology of radicular LBP. We have used a structured questionnaire to evaluate the sensory qualities associated with "shooting" and "radiating" in 155 patients, 98 with radicular LBP and 57 with trigeminal neuralgia, a second chronic pain condition in which shooting/radiating are experienced. Results indicated a spectrum of different sensations in different people. Although many sciatica patients reported rapid downward movement of their pain, even more reported downward expansion of the area of pain, some reported upward movement, and for some, there was no spatial dynamic at all. The velocity of movement or expansion was also variable. By cross-referencing sensations experienced in the sciatica and trigeminal neuralgia cohorts with known signal processing modes in the somatosensory system, we propose testable hypotheses concerning the pathophysiology of the various vectorial sensations reported, their direction and velocity, and the structures in which they are generated. Systematic evaluation of qualitative features of "shooting" and "radiating" pain at the time of diagnosis can shed light on the pain mechanism in the individual patient and perhaps contribute to a better therapeutic outcomes.

Objective: Previous findings have demonstrated that torture survivors exhibit chronic pain and alterations in pain perception. However, not much is known regarding the characteristics of the torture experience and its contribution to these long-term ramifications. The current study examined the unique role of objective severity and subjective suffering in torture in predicting chronic pain and acute pain perception and pain modulation., Method: Eighteen years after war, 59 former prisoners of war who were subjected to severe torture in captivity were assessed for subjective suffering in torture and estimated weight loss during captivity (an indication of torture severity) using self-administered questionnaires. Thirty-five years after captivity, systemic quantitative somatosensory testing was conducted, which included the measurement of pain threshold, pain tolerance, conditioned pain modulation, and perceived suprathreshold stimuli. Self-administered questionnaires were also used to evaluate chronic pain and posttraumatic stress disorder., Results: The findings indicated that subjective suffering was associated with pain threshold, conditioned pain modulation, perceived suprathreshold stimuli, and chronic pain while controlling for posttraumatic stress symptoms. Estimated weight loss was associated only with pain threshold., Conclusion: The findings demonstrate that the experience of chronic and acute pain is rooted in the subjective perception of traumatic experiences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effect of acute stress on pain threshold and intolerance threshold are reported as producing either hypoalgesia or hyperalgesia. Yet, the contribution of individual stress reactivity in this respect has not been established. The aim was to test 2 pain modulation paradigms under acute stress manipulation, to our knowledge, for the first time, to study whether stress differentially affects pain modulation, and whether the effect is related to individual stress response. Participants were 31 healthy subjects. Conditioned pain modulation (CPM) and pain adaptation were measured before and after inducing an acute stress response using the Montreal Imaging Stress Task. Subjects' stress response was evaluated according to salivary cortisol, autonomic function, and perceived stress and anxiety. The Montreal Imaging Stress Task induced a validated stress response. On a group level, stress induced reduction in CPM magnitude and increase in pain adaptation compared with baseline. These responses correlated with stress reactivity. When the group was subdivided according to stress reactivity, only high stress responders exhibited reduced CPM whereas only low stress responders exhibited increased pain adaptation. The results suggest that acute stress may induce opposite effects on pain modulation, depending on individual stress reactivity magnitude, with an advantage to low stress responders., Perspective: This study evaluated the effect of acute stress on pain modulation. Pain modulation under stress is affected by individual stress responsiveness; decreased CPM occurs in high stress responders whereas increased pain adaptation occurs in low stress responders. Identification of high stress responders may promote better pain management., (Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.)

Orientation to bodily signals is defined as the way somatic sensations are attended, perceived and interpreted. Research suggests that trauma exposure, particularly the pathological reaction to trauma (i.e., PTSD), is associated with catastrophic and frightful orientation to bodily signals. However, little is known regarding the long-term ramifications of trauma exposure and PTSD for orientation to bodily signals. Less is known regarding which PTSD symptom cluster manifests in the 'somatic route' through which orientation to bodily signals is altered. The current study examined the long-term implications of trauma and PTSD trajectories on orientation to bodily signals. Fifty-nine ex-prisoners of war (ex-POWs) and 44 controls were assessed for PTSD along three time-points (18, 30 and 35 years post-war). Orientation to bodily signals (pain catastrophizing and anxiety sensitivity-physical concerns) was assessed at T3. Participants with a chronic PTSD trajectory had higher pain catastrophizing compared to participants with no PTSD. PTSD symptom severity at T2 and T3 mediated the association between captivity and orientation. Among PTSD symptom clusters, hyperarousal at two time-points and intrusion at three time-point mediated the association between captivity and orientation. These findings allude to the cardinal role of long-term PTSD in the subjective experience of the body following trauma., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Study Design: Cross-sectional study., Objectives: Central neuropathic pain (CNP) is common after spinal cord injury (SCI). The psychological impact of CNP is not clear. Previous studies reported depression and pain catastrophizing among patients with SCI and CNP; however, the lack of control groups prevented discerning whether these were attributed to CNP or to the SCI itself. The aim was to examine the psychological distress among individuals with SCI with and without CNP and controls to evaluate its impact and possible source., Setting: Outpatient clinic of a large rehabilitation center., Methods: Individuals with SCI and CNP (n = 27) and without CNP (n = 23), and able-bodied controls (n = 20) participated. Data collection included sociodemographics, SCI characteristics, and level of post-traumatic stress disorder (PTSD), anxiety, stress, depression, and pain catastrophizing. The sensory, affective, and cognitive dimensions of CNP were analyzed., Results: Individuals with SCI and CNP exhibited elevated levels of PTSD, anxiety, stress, depression, and pain catastrophizing compared to the two control groups, which presented similar levels. The psychological variables among the CNP group correlated positively only with the affective dimension of CNP. Neither CNP nor the psychological variables correlated with SCI characteristics., Conclusions: Irrespective of CNP intensity, the affective dimension (suffering) is associated with increased psychological distress. Perhaps individual differences in the response to SCI and/or individual traits rather than the mere exposure to SCI may have a role in the emergence of CNP and psychological distress/mood dysfunction. Rehabilitation programs should prioritize stress management and prevention among individuals with SCI and CNP.

Trauma survivors, and particularly torture survivors, suffer from high rates of chronic pain and posttraumatic stress disorder (PTSD) for years afterward, along with alterations in the function of the pain system. On the basis of longitudinal data on PTSD symptomatology, we tested whether exposure to torture, PTSD or PTSD trajectories accounted for chronic pain and altered pain perception. Participants were 59 torture survivors and 44 age-matched healthy control subjects. Chronic pain was characterized. Pain threshold, pain tolerance, conditioned pain modulation (CPM), and temporal summation of pain were measured. Three PTSD trajectories were identified among torture survivors; chronic, delayed, and resilient. Lack of CPM and more intense chronic pain was found among the chronic and delayed groups compared with the resilient and healthy control groups. Temporal summation of pain was strongest among the chronic group. PTSD trajectories mediated the relationship between torture and CPM. It appears that the duration and severity of posttraumatic distress, rather than the exposure to trauma, are crucial factors that mediate the association between trauma and chronic pain. Because PTSD and its resultant distress are measurable, their evaluation seems particularly important in the management of pain among trauma survivors. The results may be generalized to other instances in which chronic pain persists after traumatic events., Perspective: This article presents the mediation effect of PTSD trajectory on pain modulation among trauma survivors suggesting that it is the duration and severity of PTSD/distress, rather than the exposure to trauma per se, that influence the perception and modulation of pain., (Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.)