Pain sensitivity in posttraumatic stress disorder and other anxiety disorders: a preliminary case control study

Inflammatory injury induces pain sensitization that is expressed beyond the site of injury in male (and not in female) mice

Pain is a crucial protective mechanism for the body. It alerts us to potential tissue damage or injury and promotes the avoidance of harmful stimuli. Injury-induced inflammation and tissue damage lead to pain sensitization, which amplifies responses to subsequent noxious stimuli even after an initial primary injury has recovered. This phenomenon, commonly referred to as hyperalgesic priming, was investigated in male and female mice to determine whether it is specific to the site of previous injury. We used 10μl of 50 % Freund's complete adjuvant (CFA) administered to the left hind paw as a model of peripheral injury. Both male and female mice exhibited robust site-specific mechanical hypersensitivity after CFA, which resolved within one-week post-injection. After injury resolution, only male CFA-primed mice showed enhanced and prolonged mechanical sensitivity in response to a chemical challenge or a single 0.5 mA electric footshock. Among CFA-primed male mice, shock-induced mechanical hypersensitivity was expressed in both the left (previously injured) and the right (uninjured) hind paws, suggesting a pivotal role for altered centralized processes in the expression of pain sensitization. These findings indicate that pain history regulates sensory responses to subsequent mechanical and chemical pain stimuli in a sex-specific manner-foot-shock-induced hyperalgesic priming expression among male mice generalized beyond the initial injury site.

Traumatic Life Experience and Pain Sensitization: Meta-analysis of Laboratory Findings

OBJECTIVES

Psychological trauma often co-occurs with pain. This relationship has been explored using laboratory pain measures; however, findings have been mixed. Previous studies have limited operationalization of trauma (eg, posttraumatic stress disorder) or pain (eg, pain thresholds), which may contribute to conflicting results. Further, prior reviews likely underrepresent trauma experiences among people who are not receiving clinical care, limiting generalizability.

MATERIALS AND METHODS

We systematically reviewed the existing literature on the relationship between psychological trauma (eg, car accidents, sexual assault, childhood abuse, neglect) and laboratory pain (ie, quantitative sensory testing measures of pain threshold, intensity, summation, modulation), using inclusive criteria. The direction of the relationship between psychological trauma and pain sensitivity was evaluated, and moderation by purported pain mechanism (ie, pain detection, suprathreshold pain, central sensitization, inhibition) was explored.

RESULTS

Analyses were conducted using 48 studies that provided 147 effect sizes. A multivariate random-effects model with robust variance estimation resulted in a small but statistically significant overall effect size of g=0.24 (P=0.0002), reflecting a positive association between psychological trauma and enhanced laboratory pain sensitivity. Upon examination of mechanistic moderators, this relationship appears driven by effects on pain detection (g=0.28, P=0.002) and central sensitization (g=0.22, P=0.04). While effect sizes were similar across all moderators, effects on suprathreshold pain and inhibition were not statistically significant.

DISCUSSION

Findings demonstrate an overall pattern of trauma-related pain enhancement and point to central sensitization as a key underlying mechanism.

Temperature Perception in the Blushing Region

Abstract. Background: Individuals with social phobia are characterized by a heightened sensitivity for physical symptom such as blushing. Objectives: We exploratorily examined whether blushing-fearful individuals with / without social phobia were more sensitive to perceiving facial temperature increases compared to healthy controls. Methods: 50 participants were tested using an adaptive two-alternative forced-choice task. A Peltier element was attached to the cheek and repeatedly warmed up in one of two phases. The participants’ task was to indicate in which of the two phases the temperature had increased. Results: Contrary to our hypothesis, blushing-fearful individuals with social phobia ( n = 11) were less sensitive to facial temperature increases, i. e., exhibited higher temperature perception threshold, than the subclinical group ( n = 14) and healthy controls ( n = 23). Limitations: The preliminary nature of our study should be noted, and replication in a larger sample is warranted. Conclusions: The findings may be best understood within a predictive coding framework: Individuals with social phobia may rely on priors when assessing their physical symptoms to form an impression of their public self in social situations.

The Experiences of Persistent Pain Among Women With a History of Intimate Partner Violence: A Systematic Review

Women experience persistent pain at higher rates than men; however, women are less likely to be provided with adequate or appropriate care and more likely to have their pain experiences dismissed. The purpose of this review is to consider the complex interaction of the biopsychosocial factors in the experience of persistent pain in order to inform improved models of care. Given persistent pain is among the most frequently reported health consequences of intimate partner violence (IPV), this review focused on studies exploring the association between persistent pain and IPV. Three reviewers independently and systematically searched seven databases. Qualitative and quantitative studies describing the association between IPV and persistent pain published between January 2000 and June 2018 were included. Twelve studies met the inclusion criteria. The included studies demonstrated that a history of IPV places an additional burden on women who experience persistent pain that cannot be explained by an underlying psychological condition. Health care practitioners should be aware of this phenomena to ensure diagnosis, assessment, and treatment plans are targeted accordingly. Future policy directives and research should account for and seek to elucidate this additional burden.

A Systematic Review of Thermosensation and Thermoregulation in Anxiety Disorders

Objectives: Sweating, hot flushes, and blushing are symptoms frequently reported by individuals with anxiety disorders. They represent important reinforcers of anxiogenic cognitions and behaviours. One system that may be involved in the manifestation of these symptoms is the thermosensory/thermoregulatory system. The aim of the present study was to investigate to what extent individuals with anxiety disorders are characterised by alterations in this system.

Methods: PubMed and PsycINFO were systematically searched. Studies were eligible if they (i) assessed individuals with anxiety disorders, (ii) thermosensation or thermoregulatory effectors/outcomes, and (iii) used a case-control design.

Results:N = 86 studies were identified. There was no evidence of altered thermosensation in individuals with anxiety disorders. Regarding thermoregulatory effectors, individuals with social anxiety disorder exhibited altered cutaneous vasodilation upon pharmacological challenge; individuals with specific phobia showed increased sweating upon confrontation with phobic stimuli; individuals with panic disorder showed increased daily sweating as well as increased sweating in response to non-phobic and phobic stimuli. Regarding thermoregulatory outcomes, there was evidence for altered skin temperature in all subtypes of anxiety.

Conclusion: Whereas there was no evidence of altered thermoregulation in specific phobia, a subgroup of individuals with social anxiety and panic disorder appears to exhibit altered vasodilation and sweating, respectively. Longitudinal research is warranted to investigate whether this represents a vulnerability to anxiety/panic.

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.

Associations between symptoms of posttraumatic stress disorder, pain, and alcohol use disorder among OEF/OIF/OND veterans

BACKGROUND

Alcohol use disorder (AUD) is prevalent among Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn (OEF/OIF/OND) veterans. Pain and posttraumatic stress disorder (PTSD) are highly comorbid and increase risk of AUD. Prior studies linking pain or PTSD to AUD have not explored interactions between pain and PTSD symptoms.

METHODS

OEF/OIF/OND veterans (N = 1230) were recruited from social media websites for a cross-sectional study of health behavior. Pain was assessed using the Pain Outcomes Questionnaire. PTSD symptoms and PTSD symptom clusters were assessed using the Posttraumatic Stress Disorder Checklist for DSM-5. AUD symptoms were assessed with the AUD Identification Test. Linear regression models were used to test for main and interaction effects in the full sample and separately by sex.

RESULTS

Both pain and PTSD symptoms were associated with increased AUD symptomology, though the relationship between pain and AUD was heighted at relatively low PTSD symptoms. With respect to PTSD symptom clusters, re-experiencing and negative cognitions and mood were associated with increased AUD symptomology. Interactions between pain and re-experiencing as well as pain and avoidance were revealed. Results for men mirrored the full sample, while an interaction between pain and negative cognitions and mood was associated with AUD in women.

CONCLUSIONS

Results highlight associations between AUD, PTSD symptoms, and pain among veterans. While the relationship between pain and AUD appeared stronger in the context of low PTSD symptoms, both pain and PTSD symptoms were associated with increased AUD. Clinicians treating veterans with AUD should address the range of potential comorbidities.

Blunted Pain Modulation Response to Induced Stress in Women with Fibromyalgia with and without Posttraumatic Stress Disorder Comorbidity: New Evidence of Hypo-Reactivity to Stress in Fibromyalgia?

There is evidence regarding the presence of alterations in both the stress response and the endogenous pain modulation systems of people with fibromyalgia (FM). However, research on pain modulation under induced stress on FM patients is scarce and contradictory. The present study analyzes stress-induced changes in pain and intolerance thresholds among FM patients, examining the possible existence of differences linked to PTSD comorbidity and gaining insights into the role of cardiovascular reactivity. Eighteen women diagnosed with FM and comorbid PTSD (FM + PTSD), 18 women diagnosed with FM and no PTSD (FM-PTSD), and 38 healthy women (HC) were exposed to the Social Stress Test task. Pressure pain thresholds and intolerance thresholds were measured before and during stress induction, and after a recovery period, while systolic blood pressure and heart rate were simultaneously recorded. Overall, while pain thresholds decreased during stress and recovery for HC, no significant changes were observed for women with FM. The intolerance threshold decreased for HC during stress, but was maintained at basal level during recovery. FM-PTSD women exhibited a delayed response, with a drop at recovery. For FM + PTSD, tolerance levels remained unchanged. In addition, cardiovascular reactivity did not seem to explain these results. This performance of the pain modulation system seems to follow the same pattern of hypoactive responsiveness under stressors that has previously been observed in FM patients on the autonomic and neuroendocrine axes. Such a hypoactive pattern may involve a non-adaptive response that may contribute to the development and maintenance of chronic pain.

Functional impairment in Posttraumatic Stress Disorder: A systematic review and meta-analysis

Posttraumatic Stress Disorder (PTSD) is a serious and debilitating condition often associated with significant impairments in daily functioning. To date, research on the complexity of functional impairment in individuals with PTSD is scarce and only limited. Yet, a quantitative synthesis and comprehensive review of existing evidence is needed to better characterize the magnitude of functional impairment in PTSD in distinct domains. We conducted a systematic literature search including observational studies comparing functioning of individuals with and without PTSD. Random effects meta-analyses were performed for the different functional domains according to the WHO International Classification of Functioning, Disability and Health (ICF). The protocol followed the MOOSE guidelines for systematic reviews. A total of thirty-four studies comprising 14 206 participants were included in the study. Compared to healthy individuals, subjects with PTSD showed significant (ps < 0.001) impairments with large to very large effect sizes (ds > 1) in all domains. Subjects with, compared to without, PTSD showed significant (ps < 0.001) impairments with medium to large effect sizes (ds > 0.5) in the domains General Tasks and Demands, Mobility, Self Care, Domestic Life, Interpersonal Interactions and Relationships, Major Life Areas and Community, Social and Civic Life. Significant impairments with small to medium effect sizes in the same domains were observed comparing PTSD to other mental disorders. In conclusion, PTSD has a significant impact on most areas of daily functioning as conceptualized in the International Classification of Functioning, Disability and Health (ICF) of the WHO. Early detection and targeted treatment of functional deficits is warranted in this patient population.

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

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.

The Relationship of Post-traumatic Stress Disorder to End-of-life Care Received by Dying Veterans: a Secondary Data Analysis

BACKGROUND

Post-traumatic stress disorder (PTSD) can be exacerbated by subsequent trauma, but it is unclear if symptoms are worsened by impending death. PTSD symptoms, including hyperarousal, negative mood and thoughts, and traumatic re-experiencing, can impact end-of-life symptoms, including pain, mood, and poor sleep. Thus, increased symptoms may lead to increased end-of-life healthcare utilization.

OBJECTIVES

To determine if veterans with PTSD have increased end-of-life healthcare utilization or medication use and to examine predictors of medication administration.

DESIGN

Secondary analysis of a stepped-wedge design implementation trial to improve end-of-life care for Veterans Affairs (VA) inpatients. Outcome variables were collected via direct chart review. Analyses included hierarchical, generalized estimating equation models, clustered by medical center.

SUBJECTS

Veterans, inpatient at one of six VA facilities, dying between 2005 and 2011.

MAIN MEASURES

Emergency room (ER) visits, hospitalizations, and medication administration in the last 7 days of life.

KEY RESULTS

Of 5341 veterans, 468 (8.76%) had PTSD. Of those, 21.4% (100/468) had major depression and 36.5% (171/468) had anxiety. Veterans with PTSD were younger (mean age 65.4 PTSD, 70.5 no PTSD, p < 0.0001) and had more VA hospitalizations and ER visits in the last 12 months of life (admissions: PTSD 2.8, no PTSD 2.4, p < 0.0001; ER visits: 3.2 vs 2.5, p < 0.0001). PTSD was associated with antipsychotic administration (OR 1.52, 95% CI 1.06-2.18). Major depression (333/5341, 6.2%) was associated with opioid administration (OR 1.348, 95% CI 1.129-1.609) and benzodiazepines (OR 1.489, 95% CI 1.141-1.943). Anxiety disorders (778/5341, 14.6%) were only associated with benzodiazepines (OR 1.598, 95% CI 1.194-2.138).

CONCLUSIONS

PTSD's association with increased end-of-life healthcare utilization and increased antipsychotic administration in the final days of life suggests increased symptom burden and potential for terminal delirium in individuals with PTSD. Understanding the burden of psychiatric illness and potential risks for delirium may facilitate the end-of-life care for these patients.

TRIAL REGISTRATION

NCT00234286.

Validation of Universal Scale in Oral Surgery (USOS) for Patient's Psycho-emotional Status Rating

Objectives

There aren’t any objective methods that may help in standard evaluation of oral surgery patient’s psycho-emotional status. Without any standardized evaluation, two main problems appear: heterogeneity between studies and ineffective patient’s evaluation. Therefore, Universal Scale in Oral Surgery (USOS) for patient’s psycho-emotional status rating has previously been proposed by authors. The aim of present study is to assess the clinical effectivity and validate the Universal Scale in Oral Surgery in case of outpatient tooth extraction for adult healthy patients.

Material and Methods

Clinical trial to validate the USOS for patient’s psycho-emotional status rating was performed. In total 90 patients, that came for outpatient dental extraction to Lithuanian University of Health Sciences Oral and Maxillofacial Surgery Department ambulatory, were enrolled in clinical trial. Patients filled self-reported questionnaires before the procedure. Operating surgeon rated USOS for patient’s psycho-emotional status rating doctor’s part questionnaire after the procedure. 4 - 6 weeks later all patients were asked to fill USOS for patient’s psycho-emotional status rating questionnaire retrospectively.

Results

According to the statistical analysis, the final composition of USOS for patient’s psycho-emotional status rating that would fit to reliability coefficient should be composed from 6 patient part questions and 3 general doctor part questions.

Conclusions

Universal Scale in Oral Surgery for patient’s psycho-emotional status rating is a novel, doctor and patient rated scale which is suitable for clinical and scientific usage.

Scales used to rate adult patients' psycho-emotional status in tooth extraction procedures: a systematic review

The aim of this study was to review scales used to assess anxiety, stress, and pain in dental patients undergoing a tooth extraction procedure and to propose a novel psycho-emotional rating scale based on the relevant literature and our own experience. An electronic literature search was conducted of the National Library of Medicine database MEDLINE (Ovid) and EMBASE databases between January 2005 and April 2016. Sequential screening at the title/abstract and full-text levels was performed. The review included all human prospective or retrospective follow-up studies and clinical trials, cohort studies, case-control studies, and case series that demonstrated at least one scale used to measure tooth extraction anxiety, stress, or pain. The search resulted in 32 articles meeting the inclusion criteria. None of the studies were found to be suitable in evaluating patient's stress, pain, and fear at once. Also, no scales were found that included both the doctor's and the patient's rating. In a few studies, vital signs as psycho-emotional status indicators were rated. Guidelines for a suitable questionnaire that could be used for rating the psycho-emotional status of patients undergoing tooth extraction are listed in the present research. Further studies are required for verification and validation of offered scale.

Paradoxical Pain Perception in Posttraumatic Stress Disorder: The Unique Role of Anxiety and Dissociation

Posttraumatic stress disorder (PTSD) and chronic pain often co-occur and exacerbate each other. Elucidating the mechanism of this co-occurrence therefore has clinical importance. Previously, patients with PTSD with chronic pain were found to demonstrate a unique paradoxical pain profile: hyperresponsiveness together with hyposensitivity to pain. Our aim was to examine whether 2 seemingly paradoxical facets of PTSD (anxiety and dissociation) underlie this paradoxical profile. Patients with PTSD (n = 32) and healthy control individuals (n = 43) underwent psychophysical testing and completed questionnaires. Patients with PTSD had higher pain thresholds and higher pain ratings to suprathreshold stimuli than control individuals. Pain thresholds were positively associated with dissociation levels and negatively associated with anxiety sensitivity levels. Experimental pain ratings were positively associated with anxiety sensitivity and negatively related to dissociation levels. Chronic pain intensity was associated with anxiety, anxiety sensitivity, and pain catastrophizing. It appears that reduced conscious attention toward incoming stimuli, resulting from dissociation, causes delayed response in pain threshold measurement, whereas biases toward threatening stimuli and decreased inhibition, possibly caused by increased anxiety, are responsible for the intensification of experimental and chronic pain. The paradoxical facets of PTSD and their particular influences over pain perception seem to reinforce the coexistence of PTSD and chronic pain, and should be considered when treating traumatized individuals.

PERSPECTIVE

This article provides new information regarding the underlying mechanism of the coexistence of PTSD and chronic pain. This knowledge could help to provide better management of PTSD and chronic pain among individuals in the aftermath of trauma.