Sensitization, subjective health complaints, and sustained arousal

Expanding the notion of mechanism to further understanding of biopsychosocial disorders? Depression and medically-unexplained pain as cases in point

Evidence-Based Medicine has little consideration for mechanisms and philosophers of science and medicine have recently made pleas to increase the place of mechanisms in the medical evidence hierarchy. However, in this debate the notions of mechanisms seem to be limited to 'mechanistic processes' and 'complex-systems mechanisms,' understood as 'componential causal systems'. I believe that this will not do full justice to how mechanisms are used in biological, psychological and social sciences and, consequently, in a more biopsychosocial approach to medicine. Here, I propose, following (Kuorikoski, 2009), to pay more attention to 'abstract forms of interaction' mechanisms. The present work scrutinized review articles on depression and medically unexplained pain, which are considered to be of multifactorial pathogenesis, for their use of mechanisms. In review articles on these disorders there seemed to be a range of uses between more 'abstract forms of interaction' and 'componential causal system' mechanisms. I therefore propose to expand the notions of mechanisms considered in medicine to include that of more 'abstract forms of interaction' to better explain and manage biopsychosocial disorders.

Helpful elements in a brief work-oriented intervention targeting musculoskeletal and mental health literacy

Musculoskeletal and mental health complaints are common in the general population and frequent reasons for healthcare utilization and work absence. Illness perceptions, coping expectancies, rumination and self-stigma are important factors in the management of these health complaints and factors closely linked to health literacy (HL). The aims of the study were to identify helpful elements in a brief intervention (BI) targeting HL regarding common musculoskeletal and mental health complaints and to identify patient perceptions of how the intervention was helpful and whether it affected their subsequent coping. Three focus group interviews with 14 patients were conducted. Systematic text condensation was used for the analysis, supported by the health literacy skill (HLS) framework to sharpen the focus on intervention elements related to the acquisition and utilization of HLSs. Results revealed the importance of receiving comprehensible health information and guidance, the use of metaphors to create recognizable narratives and the use of practical examples and exercises. Normalizing the experienced health complaints, together with a safe and accommodating clinical environment, facilitated the change process. The BI initiated processes that contributed to acceptance, resilience and empowerment, aiding work-life balance and return to work. The study presents authentic narratives of value for future focus in BI.

An idiographic approach to idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) part I. Environmental, psychosocial and clinical assessment of three individuals with severe IEI-EMF

IEI-EMF refers to an environmental illness whose primary feature is the occurrence of symptoms that are attributed to exposure to weak electromagnetic fields (EMFs). There is a growing evidence that this condition is characterized by marked individual differences thus a within-subject approach might add important information beyond the widely used nomothetic method. A mixed qualitative/quantitative idiographic protocol with a threefold diagnostic approach was tested with the participation of three individuals with severe IEI-EMF. In this qualitative paper, the environmental, psychosocial, and clinical aspects are presented and discussed (results of ecological momentary assessment are discussed in Part II of this study). For two participants, psychopathological factors appeared to be strongly related to the condition. Psychological assessment indicated a severe pre-psychotic state with paranoid tendencies, supplemented with a strong attentional focus on bodily sensations and health status. The psychological profile of the third individual showed no obvious pathology. Overall, the findings suggest that the condition might have uniformly been triggered by serious psychosocial stress for all participants. Substantial aetiological differences among participants with severe IEI-EMF were revealed. The substantial heterogeneity in the psychological and psychopathological profiles associated with IEI-EMF warrants the use of idiographic multimodal assessments in order to better understand the different ways of aetiology and to facilitate person-taylored treatments.

Neural activation changes in response to pain following cognitive behavioral therapy for patients with comorbid fibromyalgia and insomnia: a pilot study

STUDY OBJECTIVES

To examine whether cognitive behavioral treatments for insomnia (CBT-I) and pain (CBT-P) lead to neural activation changes in response to pain in fibromyalgia.

METHODS

Thirty-two patients with fibromyalgia (mean age = 55.9, standard deviation = 12.2) underwent an experimental pain protocol during functional magnetic resonance imaging and completed 14-day diaries assessing total wake time, total sleep time, and pain intensity before and after CBT-I, CBT-P, or waitlist control. Random effects analysis of covariance identified regions with significant group (CBT-I, CBT-P, waitlist control) by time (baseline, post-treatment) interactions in blood oxygen level-dependent response to pain. Linear regressions using residualized change scores examined how changes in total wake time, total sleep time, and pain intensity were related to activation (blood oxygen level-dependent) changes.

RESULTS

Twelve regions exhibited small to moderate effects with significant interactions Ps < .00; right hemisphere: inferior frontal, middle occipital, and superior temporal gyri, insula, lentiform nucleus; left hemisphere: angular, superior temporal, midfrontal, inferior occipital, midtemporal, and inferior frontal gyri. Blood oxygen level-dependent response to pain decreased in 8 regions following CBT-I, and in 3 regions following CBT-P (CBT-I effects > CBT-P). Blood oxygen level-dependent response also increased in 3 regions following CBT-P and in 6 regions following waitlist control. Improved total wake time and/or total sleep time, not pain intensity, predicted decreased blood oxygen level-dependence in 7 regions (Ps < .05), accounting for 18%-47% of the variance.

CONCLUSIONS

CBT-I prompted greater decreases in neural activation in response to pain across more regions associated with pain and sleep processing than CBT-P. Reported sleep improvements may underlie those decreases. Future research examining the longer-term impact of CBT-I and improved sleep on central pain and sleep mechanisms is warranted.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Sleep and Pain Interventions in Fibromyalgia (SPIN); Identifier: NCT02001077; URL: https://clinicaltrials.gov/ct2/show/NCT02001077.

CITATION

McCrae CS, Craggs JG, Curtis AF, et al. Neural activation changes in response to pain following cognitive behavioral therapy for patients with comorbid fibromyalgia and insomnia: a pilot study. J Clin Sleep Med. 2022;18(1):203-215.

Protocol for the impact of CBT for insomnia on pain symptoms and central sensitisation in fibromyalgia: a randomised controlled trial

INTRODUCTION

Approximately 50% of individuals with fibromyalgia (a chronic widespread pain condition) have comorbid insomnia. Treatment for these comorbid cases typically target pain, but growing research supports direct interventions for insomnia (eg, cognitive behavioural treatment for insomnia (CBT-I)) in these patients. Previous research suggests sustained hyperarousal mediated by a neural central sensitisation mechanism may underlie insomnia and chronic pain symptoms in fibromyalgia. We hypothesise CBT-I will improve insomnia symptoms, improve clinical pain and reduce central sensitisation. The trial will be the first to evaluate the short-term and long-term neural mechanisms underlying insomnia and pain improvements in fibromyalgia. Knowledge obtained from this trial might allow us to develop new or modify current treatments to better target pain mechanisms, perhaps reversing chronic pain or preventing it.

METHODS AND ANALYSIS

Female participants (n=130) 18 years of age and older with comorbid fibromyalgia (with pain severity of at least 50/100) and insomnia will be recruited from the University of Missouri in Columbia, Missouri, and surrounding areas. Participants will be randomised to 8 weeks (plus 4 bimonthly booster sessions) of CBT-I or a sleep hygiene control group (SH). Participants will be assessed at baseline, post-treatment, 6 and 12 months follow-ups. The following assessments will be completed: 2 weeks of daily diaries measuring sleep and pain, daily actigraphy, insomnia severity index, pain-related disability, single night of polysomnography recording, arousal (heart rate variability, cognitive affective arousal), structural and functional MRI to examine pain-related neural activity and plasticity and mood (depression, anxiety).

ETHICS AND DISSEMINATION

Ethics approval was obtained in July 2018 from the University of Missouri. All data are expected to be collected by 2022. Full trial results are planned to be published by 2024. Secondary analyses of baseline data will be subsequently published.

TRIAL REGISTRATION NUMBER

NCT03744156.

Associations Among Sleep Latency, Subjective Pain, and Thermal Pain Sensitivity in Gynecologic Cancer

OBJECTIVE

Pain is common among women with gynecologic cancer and contributes to depressed mood, sleep disturbances, and likelihood of future chronic pain. Little is known about how psychosocial factors are associated with central sensitization of pain in gynecologic cancer. This study examined relations among depressive symptoms, sleep, subjective pain, and aftersensation pain (a proxy for central sensitization of pain) in gynecologic cancer.

METHODS

Participants were 42 women (mean age [SD] = 59.60 [10.11] years) enrolled in a randomized clinical trial examining psychological intervention effects on sleep, pain, mood, and stress hormones/cytokines in gynecologic cancer. Six to eight weeks after surgery, participants completed an assessment of depressive symptoms, sleep, and subjective pain and a temporal summation of pain protocol via quantitative sensory testing (QST).

RESULTS

Controlling for recent chemotherapy, history of chronic pain, and analgesic medication use, regression analyses revealed that longer sleep onset latency (SOL; B = 3.112, P = 0.039, bias-corrected and accelerated (BCa) 95% confidence interval [CI] = 0.371 to 6.014) and greater sensory pain (B = 0.695, P = 0.023, BCa 95% CI = 0.085 to 1.210) were associated with greater aftersensation pain at 15 seconds. Greater sensory pain scores were associated with greater aftersensation pain at 30 seconds (B = 0.286, P = 0.045, BCa 95% CI = 0.008 to 0.513). Depression was not associated with aftersensation pain. The overall models accounted for 44.5% and 40.4% of the variance in aftersensation pain at 15 and 30 seconds, respectively. Conclusions. Longer SOL and higher subjective sensory pain were related to greater aftersensation of experimentally induced pain in women postsurgery for gynecologic cancers. Interventions that improve sleep and subjective sensory pain during the perisurgical period may reduce risk for central sensitization of pain.

Quantitative sensory testing and predicting outcomes for musculoskeletal pain, disability, and negative affect: a systematic review and meta-analysis

Hypersensitivity due to central pain mechanisms can influence recovery and lead to worse clinical outcomes, but the ability of quantitative sensory testing (QST), an index of sensitisation, to predict outcomes in chronic musculoskeletal disorders remains unclear. We systematically reviewed the evidence for ability of QST to predict pain, disability, and negative affect using searches of CENTRAL, MEDLINE, EMBASE, AMED, CINAHL, and PubMed databases up to April 2018. Title screening, data extraction, and methodological quality assessments were performed independently by 2 reviewers. Associations were reported between baseline QST and outcomes using adjusted (β) and unadjusted (r) correlations. Of the 37 eligible studies (n = 3860 participants), 32 were prospective cohort studies and 5 randomised controlled trials. Pain was an outcome in 30 studies, disability in 11, and negative affect in 3. Meta-analysis revealed that baseline QST predicted musculoskeletal pain (mean r = 0.31, 95% confidence interval [CI]: 0.23-0.38, n = 1057 participants) and disability (mean r = 0.30, 95% CI: 0.19-0.40, n = 290 participants). Baseline modalities quantifying central mechanisms such as temporal summation and conditioned pain modulation were associated with follow-up pain (temporal summation: mean r = 0.37, 95% CI: 0.17-0.54; conditioned pain modulation: mean r = 0.36, 95% CI: 0.20-0.50), whereas baseline mechanical threshold modalities were predictive of follow-up disability (mean r = 0.25, 95% CI: 0.03-0.45). Quantitative sensory testing indices of pain hypersensitivity might help develop targeted interventions aiming to improve outcomes across a range of musculoskeletal conditions.

Musculoskeletal pain in Primary Care Physiotherapy: Associations with demographic and general health characteristics

BACKGROUND

Many patients reporting musculoskeletal pain present to Primary Care Physiotherapy with costly comorbid overlapping complaints that remain medically unexplained. These subjective health complaints (SHC) incorporate coexisting multi-site musculoskeletal pain and varied non-musculoskeletal complaints (e.g. anxiety, tiredness). The role of these non-musculoskeletal complaints is acknowledged in spinal musculoskeletal disorders, but less so for peripheral musculoskeletal disorders.

OBJECTIVE

This cross-sectional study explored the relationships between self-reported musculoskeletal pain sites, non-musculoskeletal complaints and disability among people reporting spinal or peripheral musculoskeletal pain.

METHODS

Fifty individuals with spinal musculoskeletal pain and fifty with peripheral musculoskeletal pain provided data on disability, number of musculoskeletal pain sites and non-musculoskeletal complaints. Relationships between these variables were examined for each group using Pearson's correlation coefficient and linear regression analysis.

RESULTS

Participants with spinal musculoskeletal pain recorded significantly more pain sites and non-musculoskeletal complaints than participants with peripheral musculoskeletal pain. However, there was no significant difference in disability between the groups. Non-musculoskeletal complaints were significantly associated with disability (correlation = 0.41, p < 0.01) and number of pain sites (correlation = 0.42, p < 0.01). Number of pain sites and disability were not significantly associated in either group. Participants with spinal musculoskeletal pain reported more tiredness, dizziness, anxiety and sleep problems. Participants reporting dizziness, anxiety, sadness/depression and sleep problems had higher disability.

CONCLUSION

Further studies must confirm the robustness of these associations, to permit comparisons between clinical and general populations and aid identification of causal factors. Considering SHC within individualised management programmes may improve outcomes.

Vulvodynia is not created equally: empirical classification of women with vulvodynia

Background

Vulvodynia classification is based on the sensory dimensions of pain and does not include psychological factors associated with the pain experience and treatment outcomes. Previous work has shown that individuals with chronic pain can be classified into subgroups based on pain sensitivity, psychological distress, mood, and symptom severity.

Objective

The aim of this study was to identify distinct subgroups of women with vulvodynia enrolled in the National Vulvodynia Registry. We hypothesized that women with vulvodynia can be clustered into subgroups based on distress and pain sensitivity.

Design

A cross-sectional study.

Methods

We conducted an exploratory hierarchical agglomerative cluster analysis using Ward’s cluster method and squared Euclidean distances to identify unique subgroups based on baseline psychological distress and pain sensitivity. The variables included the catastrophizing subscale of the Coping Strategies Questionnaire, the Beck Depression Inventory, the State Trait Anxiety Index-Trait scale, McGill Pain Questionnaire-Affective subscale, and vulvar and pelvic muscle pressure pain sensitivity.

Subjects

Eight sites enrolled women who presented with vaginal or vulval pain of at least 3-month duration.

Results

Two distinct subgroups, high pain sensitivity with high distress (n=27) and low pain sensitivity with low distress (n=100), emerged from the cluster analysis. Validation indicated that subgroups differed in terms of clinical pain intensity, sensory aspects of pain, and intercourse pain.

Conclusion

Empirical classification indicates that unique subgroups exist in women with vulvodynia. Providers should be aware of the heterogeneity of this condition with respect to pain-related distress and pain sensitivity.

Comorbidity in Migraine with Functional Somatic Syndromes, Psychiatric Disorders and Inflammatory Diseases: A Matter of Central Sensitization?

To approach the questions as to why migraine appears to be associated with functional somatic syndromes (FSSs) and whether central sensitization may be an underlying mechanism, the present study investigated (a) comorbidity with diagnoses of three FSSs, three psychiatric disorders, and three inflammatory diseases, (b) degree of mental health problems (stress, burnout, anxiety, depression and somatization), and (c) prevalence of ten cognitive/affective and nine airway symptoms in persons with migraine in the general population. From a randomized and stratified Swedish adult sample, questionnaire data were analyzed from 151 individuals with a diagnosis of migraine and 3,255 without migraine. The results showed (a) significant comorbidity in migraine with all FSSs, psychiatric disorders and inflammatory diseases, (b) significantly elevated scores on stress, burnout, anxiety, depression, and somatization, and (c) relatively high prevalence rates on almost all symptoms. Taken together, the results motivate future study of central sensitization as a mechanism underlying migraine.

Comorbidity in allergic asthma and allergic rhinitis: functional somatic syndromes

Based on the concept of central sensitisation, the present study tested the hypothesis of comorbidity in allergic asthma and allergic rhinitis with diagnoses of functional somatic syndromes (FSSs), including fibromyalgia, irritable bowel syndrome and migraine. Data were used from the population-based Västerbotten Environmental Health Study (n = 3406). The participants consisted of 164 individuals with allergic asthma and 298 individuals with allergic rhinitis as well as 2876 individuals without allergic or non-allergic asthma, allergic rhinitis or atopic dermatitis. Diagnoses were based on self-reports of having been diagnosed by a physician. Odds ratios (ORs) were calculated from binary logistic regression analysis, both crude and adjusted for age and education. The adjusted ORs (1.87-4.00) for all FSSs differed significantly from unity for both allergic asthma and rhinitis. The results provide support for the hypothesis of comorbidity in allergic asthma and rhinitis with FSSs. Since central sensitisation is likely to underlie FSSs, the present findings raises the question as to whether central sensitisation may also be involved in allergic asthma and rhinitis.

Windmill Noise Annoyance, Visual Aesthetics, and Attitudes towards Renewable Energy Sources

A small focused socio-acoustic after-study of annoyance from a windmill park was undertaken after local health officials demanded a health impact study to look into neighborhood complaints. The windmill park consists of 31 turbines and is located in the South of Norway where it affects 179 dwellings. Simple exposure-effect relationships indicate stronger reactions to windmills and wind turbine noise than shown internationally, with the caveat that the sample size is small (n = 90) and responses are colored by the existing local conflict. Pulsating swishing sounds and turbine engine hum are the main causes of noise annoyance. About 60 per cent of those who participated in the survey were of the opinion that windmills degrade the landscape aesthetically, and were far from convinced that land-based windmills are desirable as a renewable energy source (hydropower is an important alternative source of renewables in Norway). Attitudes play an important role in addition to visual aesthetics in determining the acceptance of windmills and the resulting noise annoyance. To compare results from different wind turbine noise studies it seems necessary to assess the impact of important modifying factors.

Intolerance to environmental chemicals and sounds in irritable bowel syndrome: Explained by central sensitization?

This study tested the hypotheses of irritable bowel syndrome showing (1) comorbidity with chemical and sound intolerance, other types of functionally somatic syndromes, and psychiatric disorders and (2) stronger than normal affective reactions to and behavioral disruptions from odorous/pungent chemicals and sounds in daily life. These hypotheses were tested by means of data from a large-scale population-based questionnaire study. The results showed comorbidity in irritable bowel syndrome with chemical and sound intolerance, fibromyalgia, migraine, post-traumatic stress disorder, generalized anxiety disorder, panic syndrome, and depression as well as strong reactions/disruptions from odorous/pungent chemicals and sounds in irritable bowel syndrome.

Psychosocial predictors of quality of life in hematological cancer

The improvement of health related Quality of Life (QOL) has become one of the main objectives of psychological interventions in cancer. The aim of this study was to analyze sociodemographic and psychosocial variables that predict the different components of QOL in a sample of 69 hemato-oncological patients. Depression, social support, disease-related stress situations, coping strategies and optimism were taken as psychosocial predictors. QOL was evaluated with the Short-Form Health Survey (SF-36). With respect to sociodemographic variables, results showed that age and time from the diagnosis were associated with a decrease in QOL, while educational level and having a partner were associated with less pain and better mental health. With respect to negative-affecting psychosocial variables, depression was associated with general health and social functioning, the coping strategy of stoicism was associated with physical and emotional roles, the number of disease-related stress situations was associated with pain, and the feeling of negative emotions associated with the illness was associated with mental health. Social support and optimism were positively associated with vitality. These results have clear clinical implications for psychological interventions aimed to improve QOL in hemato-oncological patients.

Orthostatic responses in adolescent chronic fatigue syndrome: contributions from expectancies as well as gravity

BACKGROUND

Orthostatic intolerance is common in chronic fatigue syndrome (CFS), and several studies have documented an abnormal sympathetic predominance in the autonomic cardiovascular response to gravitational stimuli. The aim of this study was to explore whether the expectancies towards standing are contributors to autonomic responses in addition to the gravitational stimulus itself.

METHODS

A total of 30 CFS patients (12-18 years of age) and 39 healthy controls underwent 20° head-up tilt test and a motor imagery protocol of standing upright. Beat-to-beat cardiovascular variables were recorded.

RESULTS

At supine rest, CFS patients had significantly higher heart rate, diastolic blood pressure, and mean arterial blood pressure, and lower stroke index and heart rate variability (HRV) indices. The response to 20° head-up tilt was identical in the two groups. The response to imaginary upright position was characterized by a stronger increase of HRV indices of sympathetic predominance (power in the low-frequency range as well as the ratio low-frequency: high-frequency power) among CFS patients.

CONCLUSIONS

These results suggest that in CFS patients expectancies towards orthostatic challenge might be additional determinants of autonomic cardiovascular modulation along with the gravitational stimulus per se.

Brain sensitization to external and internal stimuli

Sensitization is defined as a non-associative learning process occurring when repeated administrations of a stimulus result in a progressive amplification of a response (Shettleworth, 2010). The purpose of this review paper is to discuss whether brain sensitization is helpful in common health problems in man. The paper reviews data on brain sensitization covering increased behavioral, physiological, cognitive, and emotional responses in man and animals. The paper concludes that brain sensitization may be a helpful concept to understand subjective and "unexplained" health complaints (nonspecific muscle pain, mood changes, fatigue, and gastrointestinal complaints), and, therefore, relevant for evidence based treatment and prevention of these common health problems.

Multiple symptoms and medically unexplained symptoms--closely related concepts in general practitioners' evaluations. A linked doctor-patient study

OBJECTIVES

Symptoms for which doctors cannot find a clear medical explanation, medically unexplained symptoms (MUS), represent a challenge in medical practice. Recent proposals to define this phenomenon are based on patients' symptom count, without distinguishing between medically explained and unexplained symptoms. We describe how general practitioners (GPs) evaluate multiple and medically unexplained symptoms, and how these dimensions are interconnected. Furthermore, we explore how the number of patient-reported symptoms is associated with the two axes.

METHODS

A multi-centre, doctor-patient-linked cross-sectional study in general practice. GPs rated consecutive patients along two 11 point ordinal scales assessing multiple (Multi-scale) and medically unexplained symptoms (MUS-scale). Patients completed a questionnaire addressing 38 symptoms experienced during the previous week and 866 linked questionnaires were available for analysis.

RESULTS

GPs used the whole range of the scales, rating only a minority of the patients as "0 (not at all)". The two scales were highly correlated (r=0.80), with a quadratically weighted kappa of 0.73, reflecting substantial agreement between the scales. MUS-scores were highest in middle age. There was a tendency that Multi-scores increased with age and that correlations between the scales decreased with age, in both sexes, although partly non-significant. The number of patient-reported symptoms was moderately correlated with the two scales.

CONCLUSION

Multisymptomatology captures MUS as a continuous construct to a great degree in GPs' clinical evaluations, although the two cannot be regarded as the same phenomenon. Patient-reported symptoms seem to be a less valid proxy for MUS.

Inducing symptoms in high symptom reporters via emotional pictures: the interactive effects of valence and arousal

OBJECTIVE

Processing unpleasant emotional cues induces elevated reporting of physical symptoms, especially in people with high habitual symptom reporting. The present study examined the role of valence and arousal of emotional pictorial cues on this effect.

METHODS

Female participants (N=45; 21 high/24 low habitual symptom reporters) viewed six series of emotional pictures with a homogeneous affective content: low arousal/positive, high arousal/positive, low arousal/negative, high arousal/negative-disgust, high arousal/negative-threat and neutral. Heart rate (HR) and skin conductance level (SCL) were recorded during picture viewing and a symptom checklist and valence and arousal ratings were completed after each trial.

RESULTS

High habitual symptom reporters reported more symptoms than low habitual symptom reporters overall, but this difference was more pronounced when processing unpleasant high arousing cues. No group differences were found on physiological measures for any of the conditions, while perceived valence and arousal both moderated the relationship between habitual symptom reporting and symptom induction.

CONCLUSION

These findings show an interactive effect of unpleasantness and high arousal on elevated symptom reporting in high habitual symptom reporters, suggesting that different characteristics of emotional cues contribute to a somatic memory activation process leading to the experience of elevated symptoms.

Acute stress induces hyperacusis in women with high levels of emotional exhaustion

Background

Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis) in individuals with high levels of emotional exhaustion (EE).

Methods

Hyperacusis was assessed using uncomfortable loudness levels (ULL) in 348 individuals (140 men; 208 women; age 23–71 years). Multivariate analyses (ordered logistic regression), were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA). Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording).

Results

There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA). However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5–6.5 dB). Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns) and 2.2 (4 kHz, right ear; left ns) times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax.

Conclusion

Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.

Inflammatory fatigue and sickness behaviour - lessons for the diagnosis and management of chronic fatigue syndrome

Persistent and severe fatigue is a common part of the presentation of a diverse range of disease processes. There is a growing body of evidence indicating a common inflammatory pathophysiology underlying many conditions where fatigue is a primary patient concern, including chronic fatigue syndrome. This review explores current models of how inflammatory mediators act on the central nervous system to produce fatigue and sickness behaviour, and the commonality of these processes in conditions as diverse as surgical trauma, infection, various cancers, inflammatory bowel disease, connective tissue diseases and autoimmune diseases. We also discuss evidence indicating chronic fatigue syndrome may have important pathophysiological similarities with cytokine mediated sickness behaviour, and what lessons can be applied from sickness behaviour to chronic fatigue syndrome with regards to the diagnosis and management.

Neural and psychosocial mechanisms of pain sensitivity in fibromyalgia

Fibromyalgia is a chronic musculoskeletal pain disorder that affects an estimated 5 million adults in the U.S. The hallmark is burning, searing, tingling, shooting, stabbing, deep aching, or sharp pain. Fibromyalgia is generally considered to be a "central sensitivity syndrome" where central sensitization is regarded as the cause of pain in its own right. Nonetheless, the case continues to be made that all central and spatially distributed peripheral components of fibromyalgia pain would fade if the peripheral generators could be silenced. Although neural mechanisms are clearly important in pain sensitivity, cognitive and social mechanisms also need to be considered. The aim of this review is to examine four mechanisms responsible for heightened pain sensitivity in fibromyalgia: peripheral sensitization, central sensitization, cognitive-emotional sensitization, and interpersonal sensitization. The purpose of framing the review in terms of pain sensitivity in fibromyalgia is to highlight that different mechanisms of sensitization are appropriately regarded as intervening variables when it comes to understanding individual differences in the experience of pain. The paper concludes by considering the implications of the findings of the review for explanations of fibromyalgia pain by nurses working in multidisciplinary teams. The trend appears to be able to explain the cause of fibromyalgia pain in terms of sensitization per se. The recommended alternative is to explain fibromyalgia pain in terms of changes in pain sensitivity and the role of underlying neural and psychosocial mechanisms.

The effect of a mental stressor on conditioned pain modulation in healthy subjects

Background and purpose

In animal studies, enhanced sensitivity to painful stimuli succeeding chronic stress has been reported, while acute stress is reported to induce analgesia. Human studies on the effect of mental stress on pain are more equivocal. A disturbed stress-response resulting in an increased sensitivity to painful stimuli has also been discussed as a potential mechanism for e.g., the fibromyalgia syndrome. Endogenous analgesia may be studied in humans by measuring the analgesic effect of heterotopic noxious conditioning stimulation. In neurophysiological animal studies this phenomenon was originally denoted “diffuse noxious inhibitory controls” (DNIC), but for human studies it has been suggested to use the term conditioned pain modulation (CPM).

The clinical relevance of aberrances in CPM is not clear. Inhibitory CPM is reported as being reduced in several medically unexplained syndromes with musculoskeletal pain aggravated by mental stress. However, whether the reported reduced CPM effects are causally related to clinical pain is unknown.

In the present study the effect of a mental stressor on CPM is studied.

Methods

With tourniquet-induced pain as the conditioning stimulus we estimated the CPM effect in twenty healthy subjects. Heat pain threshold (HPT), supra-threshold heat pain level (SHPL) and pressure pain threshold (PPT) were used as test stimuli. Measurements were performed at baseline, after a stressful task and after a non-stressful task presented in a blinded cross-over design. We used repeated-measures ANOVAs in the analysis with simple contrasts for post hoc analysis.

Results

With a ANOVA repeated measures model we found a significant task effect (F = 18.5, p ≤ 0.001), indicating that CPM was successfully induced. In our ANOVA model, we found a significant effect of stress in the contrast analysis (F = 5.2, p = 0.037), indicating that CPM was affected by the stressful task. The effects on PPT could not be analyzed due to a significant carry-over effect (for PPT only).

Conclusions

In the present blinded crossover study, we found a significant small to medium inhibitory effect of mental stress upon the CPM of thermal pain.

Implications

Our results suggest that previously reported reduced inhibitory CPM in several medically unexplained syndromes with musculoskeletal pain aggravated by mental stress possibly can be related to confounding or clinically relevant stress level differences. However, the result might be modality-specific. Further studies in patients are obviously needed, and the impact of mental stress on CPM should be investigated also with other stressors.

Multiple chemical sensitivity: on the scent of central sensitization

BACKGROUND

Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor contributing to the clinical manifestations.

PURPOSE

To use quantitative sensory testing (QST) to study central hyperexcitability and multiple aspects of central sensory processing in MCS patients without comorbid overlapping disorders and to compare the results with those among matched controls.

METHODS

15 MCS patients and 15 healthy matched controls underwent QST to assess the following aspects of pain: capsaicin-induced secondary punctate hyperalgesia, stimulus response function (SRF) to punctate mechanical stimuli before and after capsaicin injection, temporal summation to punctate stimuli post capsaicin injection, pressure pain thresholds, heat pain thresholds, tonic heat stimulation and conditioning pain modulation (CPM: formerly known as diffuse noxious inhibitory control or DNIC).

RESULTS

The mean area of capsaicin-induced secondary punctate hyperalgesia was significantly larger in MCS patients than in controls at 5, 30 and 60 min post capsaicin injection (p=0.01). In addition MCS patients reported higher ratings in response to punctate mechanical stimuli assessed by SRF compared with controls (p<0.001). The CPM test induced significantly higher pain ratings in patients than in controls (p=0.002). We found no group differences in pressure pain and heat pain thresholds, temporal summation to punctate stimuli post capsaicin injection, capsaicin and tonic heat pain ratings or CPM effect.

CONCLUSION

Increased capsaicin-induced secondary punctate hyperalgesia was demonstrated in MCS patients without comorbid, overlapping disorders, suggesting facilitated central sensitization in MCS.

Cortisol, sleep, and recovery - Some gender differences but no straight associations

BACKGROUND

Work related fatigue has been suggested as a link in the assumed sequence of events between repeated adverse work demands and the development of work related stress, which may be associated with changes in concentrations of cortisol, psychological overload and, in the long run, health problems. Insufficient sleep is a contributing factor to lack of recovery, but previous studies on associations between subjective aspects of sleep and recovery, and cortisol, have been inconclusive. The aim with the present study was to examine possible associations between cortisol measures and (I) self-rated recovery, (II) occupational fatigue and (III) subjective sleep quality the night preceding cortisol sampling. Further, possible gender differences were tested.

METHODS

Salivary cortisol was measured in 581 persons during a working day, at awakening, +30 min and in the evening. Various measures of subjective sleep and recovery were analyzed in relation to cortisol.

RESULTS

Few correlations between cortisol and any sleep- or recovery parameters were found. However, some significant associations were found between cortisol and a few measures of more chronic aspects of sleep and recovery. Gender stratified analyses showed somewhat differing associations among men and women. This indicates that possible associations and pathways between lack of recovery/sleepiness and cortisol, and in the long run, unhealth, may not be similar for men and women.

Somatocognitive therapy in the management of chronic gynaecological pain. A review of the historical background and results of a current approach

Historic background and development of our somatocognitive approach

Mensendieck physiotherapy of the Oslo School is a tradition of physiotherapy founded by the American physician Bess Mensendieck, a contemporary and fellow student of Sigmund Freud at the Paris School of Neurology. It builds on the principles of functional anatomy and the theories of motor learning. We have further developed the theory and practice from this physiotherapy tradition, challenged by the enormous load of patients with longstanding, incapacitating pain on western health care systems, by seeking to incorporate inspirational ideas from body oriented dynamic psychotherapy and cognitive psychotherapy. We developed somatocognitive therapy as a hybrid of physiotherapy and cognitive psychotherapy by focusing on the present cognitive content of the mind of the patient, contrary to a focus on analysis of the subconscious and interpretation of dreams, and acknowledging the important role of the body in pain-eliciting defense mechanisms against mental stress and negative emotions.

The core of this somatocognitive therapy

(1) To promote awareness of own body, (2) graded task assignment related to the motor patterns utilized in daily activities, (3) combined with an empathic attitude built on dialogue and mutual understanding, and emotional containment and support. The goal is for the patient to develop coping strategies and mastery of own life. In addition, (4) manual release of tensed muscles and applied relaxation techniques are important.

Methods and results of an illustrative study

One area in particular need of development and research is sexual pain disorders. We have applied this somatocognitive therapy in a randomized, controlled intervention study of women with chronic pelvic pain (CPP).Wesummarize methods and results of this study.

Methods

40 patients with CPP were included in a randomized, controlled intervention study. The patients were randomized into (1) a control group, receiving treatment as usual (Standard Gynecological Treatment, STGT) and (2) a group receiving STGT + Mensendieck Somatocognitive Therapy (MSCT). The patients were assessed by means of Visual Analogue Scale of Pain (VASP), Standardized Mensendieck Test (SMT) for analysis of motor patterns (posture, movement, gait, sitting posture and respiration), and General Health Questionnaire (GHQ-30) assessing psychological distress, at baseline (inclusion into study), after three months of out-patient therapy and at 1 year follow-up. Results: The women averaged 31 years, pain duration 6.1 years, average number of previous surgical procedures 1.8 per women. In the STGT group, no significant change was found, neither in pain scores, motor patterns or psychological distress during the observation period. In the group receiving STGT + MSCT, significant reduction in pain score and improvement in motor function were found at the end of therapy, and the significant improvement continued through the follow-up (64% reduction of pain scores, and 80% increase in the average score for respiration, as an example of motor pattern improvement). GHQ scores were significantly improved for anxiety and coping (p < 0.01).

Conclusions

Somatocognitive therapy is anewapproach that appears to be very promising in the management of chronic gynecological pain. Short-term out-patient treatment significantly reduces pain scores and improves motor function.

Implications

Chronic pelvic pain in women is a major health care problem with no specific therapies and poor prognosis. A novel, somatocognitive approach has documented positive effects. It is now studied by other clinical researchers in order to reinforce its evidence base.

Blunted autonomic reactivity and increased pain tolerance in somatoform patients

Somatoform disorders are characterized by the presence of multiple somatic symptoms. Patients often experience different pain syndromes, and recent research suggests that sympathovagal balance is disturbed in somatoform patients, which could be related to alteration in pain sensitivity. This study analyzed how proposed sympathovagal imbalance interacts with objective pain assessment and the imagination of pain in somatoform disorders. Twenty-one patients (4 men) with diagnosed multisomatoform disorder were included in the study and matched to healthy control subjects. Autonomic measures and heart rate variability were assessed during baseline; pain perception was assessed by means of a pressure algometer and pain imagination. We found evidence for a sympathovagal imbalance in somatoform disorders characterized by low parasympathetic activation and high sympathetic activation during all conditions. Additionally, somatoform patients had reduced pain tolerance. Vagal withdrawal during pain assessment was more pronounced for healthy control subjects and correlated positively with assessed pain tolerance. During imagination somatoform, patients reported higher pain unpleasantness and higher pain intensity as compared to control subjects. We conclude that our data demonstrate an imbalance in sympathovagal activation and a hyposensitivity to pain tolerance stimuli in somatoform disorders. Parasympathetic reactivity might form crucial information when judging pain-associated affective-motivational components. Our results might be attributable to a deficient detection of visceral signals and might be a pathogenetic mechanism for the development of emotional difficulties and increased everyday vulnerability in somatoform patients.

Depression, cytokines and experimental pain: evidence for sex-related association patterns

BACKGROUND

There is robust evidence that altered neural-immune interactions including increased levels of proinflammatory cytokines are involved in both the pathogenesis of depression and altered pain processing. Proinflammatory cytokines induce sickness behavior, a constellation of symptoms that bears a strong similarity to those of depression. A feature of sickness behavior is enhanced pain sensitivity and it has been suggested that proinflammatory cytokines interact with pain processing directly and via several neurobiological pathways. Previous research indicates that depression and pain are closely related. We investigated the association between proinflammatory cytokines and experimental pain in major depression.

METHODS

Psychopathological variables, pressure pain thresholds (PPT) and concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured in 37 outpatients with major depression and 48 healthy controls.

RESULTS

Compared with controls, depressed patients exhibited significantly higher levels of TNF-α and significantly decreased PPT indicating enhanced pain sensitivity. The group differences were robust when adjusting for sex and body mass index, although sex was significantly related to PPT. No group difference was observed in IL-6. PPT correlated significantly with TNF-α in women but not in men.

LIMITATIONS

Because of the cross-sectional design, causality of the relation between TNF-α and pain cannot be determined. Results should be considered preliminary given the small sample size.

CONCLUSION

The present findings suggest that increased pain sensitivity in depression may be linked to increased TNF-α concentration. The absence of this association in men is discussed in terms of pain-related psychobiological sex differences.

Gray matter volumes of pain-related brain areas are decreased in fibromyalgia syndrome

Fibromyalgia (FM) is a chronic, widespread musculoskeletal pain disorder that is very prevalent in the general population (approximately 5%). Accumulating evidence suggests that FM is associated with central pain processing abnormalities, ie, central sensitization. Several previous studies of chronic pain patients, including FM, have shown gray matter atrophy of brain areas associated with sensory and affective pain processing. These findings, however, have not been confirmed in all FM studies. In this study, we investigated gray matter volumes of brain areas associated with pain-related areas of FM patients identified by functional brain imaging. Using voxel-based morphometric (VBM) analysis of magnetic resonance brain images, we compared 19 pain-related brain areas of 14 female FM patients and 11 healthy controls (NC). We found that FM patients had significantly less gray matter volumes than NC in 3 of these brain regions, including the anterior and mid-cingulate, as well as mid-insular cortices. Importantly, FM patients demonstrated neither global gray matter atrophy nor gray matter changes associated with depression, as shown in some studies. Using a more stringent analysis than other VBM studies, we provide evidence for decreased gray matter volumes in a number of pain-related brain areas in FM. Although the mechanisms for these gray matter changes are presently unclear, they may contribute to some of the core features of this chronic disorder including affective disturbances and chronic widespread pain.

PERSPECTIVE

Increasing evidence supports the association of chronic pain with accelerated gray matter atrophy in pain disorders like low back pain, IBS, and FM syndrome. However, cause-effect relationships between chronic pain and decreased gray matter volumes have not been established yet and will require future prospective studies.

Stress and prevalence of hearing problems in the Swedish working population

Background

Current human and experimental studies are indicating an association between stress and hearing problems; however potential risk factors have not been established. Hearing problems are projected to become among the top ten disabilities according to the WHO in the near future. Therefore a better understanding of the relationships between stress and hearing is warranted. Here we describe the prevalence of two common hearing problems, i.e. hearing complaints and tinnitus, in relation to different work-and health-related stressors.

Methods

A total of 18,734 individuals were invited to participate in the study, out of which 9,756 (52%) enrolled.

Results

The results demonstrate a clear and mostly linear relationship between higher prevalence of hearing problems (tinnitus or hearing loss or both) and different stressors, e.g. occupational, poorer self-rated health, long-term illness, poorer sleep quality, and higher burnout scores.

Conclusions

The present study unambiguously demonstrates associations between hearing problems and various stressors that have not been previously described for the auditory system. These findings will open new avenues for future investigations.

Stress and tension-type headache mechanisms

Stress is widely demonstrated as a contributing factor in tension-type headache (TTH). The mechanisms underlying this remain unclear at present. Recent research indicates the importance of central pain processes in tension-type headache (TTH) pathophysiology. Concurrently, research with animals and healthy humans has begun to elucidate the relationship between stress and pain processing in the central nervous system, including central pain processes putatively dysfunctional in TTH. Combined, these two fields of research present new insights and hypotheses into possible mechanisms by which stress may contribute to TTH. To date, however, there has been no comprehensive review of this literature. The present paper provides such a review, which may be valuable in facilitating a broader understanding of the central mechanisms by which stress may contribute to TTH.

Duodenal administered seal oil for patients with subjective food hypersensitivity: an explorative open pilot study

Short-term duodenal administration of n-3 polyunsaturated fatty acid (PUFA)-rich seal oil may improve gastrointestinal complaints in patients with subjective food hypersensitivity, as well as joint pain in patients with inflammatory bowel disease (IBD). The aim of the present explorative pilot study was to investigate whether 10-day open treatment with seal oil, 10 mL self-administrated via a nasoduodenal tube 3 times daily, could also benefit nongastrointestinal complaints and quality of life (QoL) in patients with subjective food hypersensitivity. Twenty-six patients with subjective food hypersensitivity, of whom 25 had irritable bowel syndrome (IBS), were included in the present study. Before and after treatment and 1 month posttreatment, patients filled in the Ulcer Esophagitis Subjective Symptoms Scale (UESS) and the Gastrointestinal Symptom Rating Scale (GSRS) for gastrointestinal symptoms and subjective health complaints (SHC) inventory for nongastrointestinal symptoms in addition to short form of the Nepean dyspepsia index (SF-NDI) for evaluation of QoL. Compared with baseline, gastrointestinal, as well as nongastrointestinal, complaints and QoL improved significantly, both at end of treatment and 1 month posttreatment. The consistent improvements following seal oil administration warrant further placebo-controlled trials for confirmation of effect.

Expectations, perceptions, and physiotherapy predict prolonged sick leave in subacute low back pain

BACKGROUND

Brief intervention programs for subacute low back pain (LBP) result in significant reduction of sick leave compared to treatment as usual. Although effective, a substantial proportion of the patients do not return to work. This study investigates predictors of return to work in LBP patients participating in a randomized controlled trial comparing a brief intervention program (BI) with BI and physical exercise.

METHODS

Predictors for not returning to work was examined in 246 patients sick listed 8-12 weeks for low back pain. The patients had participated in a randomized controlled trial, with BI (n = 122) and BI + physical exercise (n = 124). There were no significant differences between the two intervention groups on return to work. The groups were therefore merged in the analyses of predictors. Multiple logistic regression analysis was used to identify predictors for non return to work at 3, 12, and 24 months of follow-up.

RESULTS

At 3 months of follow-up, the strongest predictors for not returning to work were pain intensity while resting (OR = 5.6; CI = 1.7-19), the perception of constant back strain when working (OR = 4.1; CI = 1.5-12), negative expectations for return to work (OR = 4.2; CI = 1.7-10), and having been to a physiotherapist prior to participation in the trial (OR = 3.3; CI = 1.3-8.3). At 12 months, perceived reduced ability to walk far due to the complaints (OR = 2.6; CI = 1.3-5.4), pain during activities (OR = 2.4; CI = 1.1-5.1), and having been to a physiotherapist prior to participation in the trial (OR = 2.1; CI = 1.1-4.3) were the strongest predictors for non return to work. At 24 months age below 41 years (OR = 2.9; CI = 1.4-6.0) was the only significant predictor for non return to work.

CONCLUSION

It appears that return to work is highly dependant on individual and cognitive factors. Patients not returning to work after the interventions were characterized by negative expectations, perceptions about pain and disability, and previous physiotherapy treatment. This is the first study reporting that previous treatment by physiotherapists is a risk factor for long-term sick leave. This has not been reported before and is an interesting finding that deserves more scrutiny.

Psychosocial and physiological correlates of self-reported hearing problems in male and female musicians in symphony orchestras

Experimental and epidemiological research indicate an association between long-term stress and hearing problems, yet the mechanisms underlying these disorders are not yet fully established. Thus, in order to better understand the pathogenesis of stress-related hearing problems, the present study explored the symptoms and general physiological and psychosocial status of musicians in symphony orchestras. Orchestral musicians are an ideal group to study since physical, psychosocial, work-environmental and acoustic stressors are highly prevalent. The subjects where obtained from two different studies. The first group included 250 participants from 12 orchestras and is entitled "the epidemiological study". The second group, entitled "the longitudinal study", included 47 musicians who were assessed at five occasions (every half year) during two years. Thirty-one of the 47 participants were selected for sampling of physiological variables, i.e. 24-hour ECG to assess heart rate variability to evaluate the synergistic action of the autonomic system as well as saliva cortisol and testosterone levels. The results indicate that self-reported hearing problems are associated with perceived poorer psychosocial environment, as well as mental health symptoms and stress. High-frequency power of heart rate variability (parasympathetic activity) showed a negative relationship to hearing problems, implying a poorer ability to "unwind" from stress. Cortisol levels were not correlated to hearing problems whereas testosterone levels showed a tendency to be lower in subjects with hearing problems than in others. These findings provide evidence for a relationship between long-term stress and self-reported hearing problems and demonstrate a protective role of parasympathetic and anabolic activity on hearing status.

EEG ALPHA SENSITIZATION IN INDIVIDUALIZED HOMEOPATHIC TREATMENT OF FIBROMYALGIA

Fibromyalgia (FM) patients show evidence of sensitizability in pain pathways and electroencephalographic (EEG) alterations. One proposed mechanism for the claimed effects of homeopathy, a form of complementary medicine used for FM, is time-dependent sensitization (TDS, progressive amplification) of host responses. This study examined possible sensitization-related changes in EEG relative alpha magnitude during a clinical trial of homeopathy in FM. A 4-month randomized, placebo-controlled double-blind trial of daily orally administered individualized homeopathy in physician-confirmed FM, with an additional 2-month optional crossover phase, included three laboratory sessions, at baseline, 3 and 6 months (N = 48, age 49.2 +/- 9.8 years, 94% women). Nineteen leads of EEG relative alpha magnitude at rest and during olfactory administration of treatment and control solutions were evaluated in each session. After 3 months, the active treatment group significantly increased, while the placebo group decreased, in global alpha-1 and alpha-2 during bottle sniffs over sessions. At 6 months, the subset of active patients who stayed on active continued to increase, while the active-switch subgroup reversed direction in alpha magnitude. Groups did not differ in resting alpha. Consistent with the TDS hypothesis, sniff alpha-1 and alpha-2 increases at 6 months versus baseline correlated with total amount of time on active remedy over all subjects (r = 0.45, p = .003), not with dose changes or clinical outcomes in the active group. The findings suggest initiation of TDS in relative EEG alpha magnitude by daily oral administration of active homeopathic medicines versus placebo, with laboratory elicitation by temporolimbic olfactory stimulation or sniffing.

Obstructions for quality care experienced by patients with chronic fatigue syndrome (CFS)--a case study

OBJECTIVE

To explore obstructions for quality care from experiences by patients suffering from chronic fatigue syndrome (CFS).

METHODS

Qualitative case study with data drawn from a group meeting, written answers to a questionnaire and a follow-up meeting. Purposeful sample of 10 women and 2 men of various ages, recruited from a local patient organization, assumed to have a special awareness for quality care.

RESULTS

CFS patients said that lack of acknowledgement could be even worse than the symptoms. They wanted their doctors to ask questions, listen to them and take them seriously, instead of behaving degrading. Many participants felt that the doctors psychologized too much, or trivialized the symptoms. Participants described how doctors' lack of knowledge about the condition would lead to long-term uncertainty or maltreatment. Even with doctors who were supportive, it would usually take months and sometimes years until a medical conclusion would be reached, or other disorders were ruled out. Increased physical activity had been recommend, but most of the informants experienced that this made them worse.

CONCLUSION

Current medical scepticism and ignorance regarding CFS shapes the context of medical care and the illness experiences of CFS patients, who may feel they neither get a proper assessment nor management.

PRACTICE IMPLICATIONS

CFS patients' reports about patronizing attitudes and ignorance among doctors call for development of evidence based strategies and empowerment of patients, acknowledging the patients' understanding of symptoms and the complex nature of the disease. The NICE guidelines emphasize the need of patient participation and shared decision-making.

From acute musculoskeletal pain to chronic widespread pain and fibromyalgia: application of pain neurophysiology in manual therapy practice

During the past decade, scientific research has provided new insight into the development from an acute, localised musculoskeletal disorder towards chronic widespread pain/fibromyalgia (FM). Chronic widespread pain/FM is characterised by sensitisation of central pain pathways. An in-depth review of basic and clinical research was performed to design a theoretical framework for manual therapy in these patients. It is explained that manual therapy might be able to influence the process of chronicity in three different ways. (I) In order to prevent chronicity in (sub)acute musculoskeletal disorders, it seems crucial to limit the time course of afferent stimulation of peripheral nociceptors. (II) In the case of chronic widespread pain and established sensitisation of central pain pathways, relatively minor injuries/trauma at any locations are likely to sustain the process of central sensitisation and should be treated appropriately with manual therapy accounting for the decreased sensory threshold. Inappropriate pain beliefs should be addressed and exercise interventions should account for the process of central sensitisation. (III) However, manual therapists ignoring the processes involved in the development and maintenance of chronic widespread pain/FM may cause more harm then benefit to the patient by triggering or sustaining central sensitisation.

Effects of induced stress on experimental pain sensitivity in chronic tension-type headache sufferers

BACKGROUND AND PURPOSE

It has been proposed that stress may contribute to chronic tension-type headache (CTH) through hyperalgesic effects on already sensitized pain pathways in CTH sufferers. This hypothesis could be partially tested by examining effects of stress on mechanical and thermal pain sensitivity in CTH sufferers. Such examinations have not been reported to date.

MATERIALS AND METHODS

In the present study, we measured cephalic and extra-cephalic pressure [pressure-pain threshold (PPT)] and cold-pain thresholds (CPT) in CTH sufferers (n = 8 females, n = 8 males) and healthy control subjects (n = 8 males, n = 7 females) recruited from the general population before and after exposure to a 15-min stressful mental task.

RESULTS

Results indicated that PPT's at head and hand were lower in the CTH compared with control group both before and after task exposure. PPT's and CPT's decreased from pre- to post-task in both groups, with a significantly greater pre- to post-task reduction in cephalic PPT in the CTH compared with control group. Subjective stress increased from pre- to post-task in both groups and did not differ between groups. In the CTH group, stress reactivity was negatively correlated with PPT's, whilst absolute stress levels were positively correlated with pre- to post-task decrease in PPT's.

CONCLUSIONS

The main finding is an enhanced hyperalgesic effect of stress on cephalic pressure-pain sensitivity in the CTH sufferers compared with the healthy controls. The results support the hypothesis that stress may contribute to CTH through hyperalgesic effects on already sensitized pain pathways in CTH sufferers.

A sensitive body or a sensitive mind? Associations among somatic sensitization, cognitive sensitization, health worry, and subjective health complaints

OBJECTIVES

Psychobiological sensitization and health worry appear to be involved in the etiology of clinical manifestations of subjective health complaints (SHCs) via amplified processing of health-related information. However, it is not clear whether sensitization and health worry are also associated with common SHCs, which are extremely prevalent and are responsible for a large part of both human suffering and health care costs. In this study, we investigated whether SHCs are associated with health worry and two types of sensitization: cognitive health-related sensitization and somatic sensitization. We also examined whether health worry mediates the relationship between cognitive sensitization and SHCs and whether both levels of sensitization interact.

METHODS

A nonclinical sample of 47 female students completed questionnaires about their recent subjective health as well as health worry and underwent tests for cognitive sensitization, operationalized as Stroop interference and free recall performance, and somatic sensitization, operationalized as pain tolerance and pain threshold in a cold pressor task.

RESULTS

Severity of health complaints was positively related with recall of health-related stimuli, but not with Stroop interference, and with worrying about health complaints. In addition, worry mediated the relationship between recall bias and severity of health complaints. Both the number and severity of recent health complaints were associated with pain tolerance. Pain threshold was associated with Stroop interference for health-related information.

CONCLUSIONS

The results suggest that specific types of cognitive sensitization and somatic sensitization are associated with common health complaints and that worrying about one's complaints might play a role by enhancing biased memory of health-related information.

The duration of capture and restraint during anesthesia and euthanasia influences glucocorticoid levels in male golden hamsters

Deep litter has been shown to decrease stereotypic wire-gnawing in male golden hamsters, suggesting that increased litter depth may be associated with decreased chronic stress levels. To determine the relationship between litter depth and stress levels in hamsters, the authors measured serum levels of corticosterone, cortisol, and ACTH in male golden hamsters kept in cages with three different depths of litter. The duration of handling the hamsters significantly increased the concentrations of corticosterone, cortisol, and the ratio of cortisol/corticosterone. It took longer to catch hamsters housed in cages with deep litter and the ACTH levels were higher in these hamsters. The positive effect of the enrichment (deep litter) was diminished by methodological problems during handling/anesthesia.

Dysfunctional cognitions in idiopathic environmental intolerances (IEI)—An integrative psychiatric perspective

Idiopathic environmental intolerances (IEI) - formerly multiple chemical sensitivities (MCS) - are characterized by diffuse symptoms reported after exposure to low doses of everyday chemicals. Previous theories about the origin of IEI have emphasized either biological or psychological factors, neglecting a probable interplay. Many have suggested classifying IEI as a somatoform or an anxiety disorder, irrespective of some incongruities. By focusing on dysfunctional cognitions we discuss obvious parallels of IEI with somatoform disorders, and also indicate overlaps with anxiety and delusional disorders. To propose a hypothetical psycho-neurobiological basis of IEI, recent evidence about cortically represented symptoms in the absence of peripheral stimuli is briefly summarized. We conclude that IEI can serve as an illustrative example for the impact of cognitive, representational processes in symptom generation.