Stress Response Pattern of Heart Rate Variability in Patients with Functional Somatic Syndromes

Functional somatic syndromes (FSSs) represent a clinically important group of disorders that are often stress-related. Their autonomic pathophysiology, including reduced heart rate variability (HRV), has been reported. However, the response pattern to mental stress and recovery in FSSs remains unclear. Thus, we aimed to clarify the pattern of autonomic stress response and recovery to mental arithmetic stress in patients with FSS compared to that in healthy controls. This cross-sectional study included 79 patients with FSS who visited the Department of Psychosomatic Medicine at a university hospital in Japan and 39 healthy controls. Following a mood questionnaire and obtaining epidemiologic information, HRV was measured during three periods (5 min each): relaxation baseline resting, stress (mental arithmetic task), and post-stress recovery period. The HRV analysis included inter-beat interval, low frequency power, and high frequency power. Compared to healthy controls, patients with FSS exhibited significantly higher scores on the mood questionnaire, prolonged duration of illness, and decreased functionality in daily activities. While the healthy control group showed a pronounced stress response pattern with a significant decrease in vagal HRV and recovery, the FSS group showed a "flat" vagal stress response pattern, and the HRV in the FSS group was lower at relaxation baseline, remained low during the stress, and did not change post stress. Patients with severe FSS exhibit an altered stress response pattern. Our results could provide significant clues for the diagnosis and treatment of such patients, as well as useful insights into the relationship between stress and illness.

Kappa Opioid Receptor Blockade in the Amygdala Mitigates Pain Like-Behaviors by Inhibiting Corticotropin Releasing Factor Neurons in a Rat Model of Functional Pain

Functional pain syndromes (FPS) occur in the absence of identifiable tissue injury or noxious events and include conditions such as migraine, fibromyalgia, and others. Stressors are very common triggers of pain attacks in various FPS conditions. It has been recently demonstrated that kappa opioid receptors (KOR) in the central nucleus of amygdala (CeA) contribute to FPS conditions, but underlying mechanisms remain unclear. The CeA is rich in KOR and encompasses major output pathways involving extra-amygdalar projections of corticotropin releasing factor (CRF) expressing neurons. Here we tested the hypothesis that KOR blockade in the CeA in a rat model of FPS reduces pain-like and nocifensive behaviors by restoring inhibition of CeA-CRF neurons. Intra-CeA administration of a KOR antagonist (nor-BNI) decreased mechanical hypersensitivity and affective and anxiety-like behaviors in a stress-induced FPS model. In systems electrophysiology experiments in anesthetized rats, intra-CeA application of nor-BNI reduced spontaneous firing and responsiveness of CeA neurons to peripheral stimulation. In brain slice whole-cell patch-clamp recordings, nor-BNI increased feedforward inhibitory transmission evoked by optogenetic and electrical stimulation of parabrachial afferents, but had no effect on monosynaptic excitatory transmission. Nor-BNI decreased frequency, but not amplitude, of spontaneous inhibitory synaptic currents, suggesting a presynaptic action. Blocking KOR receptors in stress-induced FPS conditions may therefore represent a novel therapeutic strategy.

Simulating the mind and applications – a theory-based chance for understanding psychic transformations in somatic symptom disorders

With the new category of somatic symptom disorder/bodily distress disorder in ICD-11, research into pathogenetic and therapeutic pathways is stimulated. By turning away from the definition of somatoform disorders as “the lack of something physical explaining everything”, this new classification might offer a way to put the focus on the individual patient’s psychodynamic balance and conflicts and their condensation in the symptom. Modelling and simulation have a long history in science to gain insight also into complex phenomena. Considering the evolution of precision medicine many different parameters are meanwhile operationalised and ready for consequent process research. Calculation models have to fit to the complexity of this disorder category. In an interdisciplinary discourse between computer and medical/psychoanalytic scientists a multilayer, fine grained calculation model is elaborated. Starting from a clinical case history, within iterative discussion, by acknowledging the demand for interdisciplinary synergy and cooperation in science, psychoanalytic theory served as the basis for computer-scientific information technique. A parallelisation with the Mealy model helped to establish a meaningful calculation possibility for further process research. How psychic transformations can be understood properly in order to provide meaningful treatments, the respective training, and to conduct appropriate process- and outcome-research is established in simulating the mind and applications.

Systematic Review of Autonomic Nervous System Functioning in Pediatric Chronic Pain

OBJECTIVES

Chronic pain is a common and debilitating health problem that impacts up to one third of children and adolescents. The pathophysiological mechanisms of chronic pain are complex, but considerable research links dysfunction of the autonomic nervous system (ANS) and chronic pain in adults. No review of ANS functioning has been conducted in pediatric chronic pain. We systematically reviewed studies examining ANS activity among youth with primary chronic pain conditions.

METHODS

A systematic search of PsycINFO, PubMed, and CINAHL was conducted using specific search terms. Articles were included if studies measured heart rate, blood pressure, heart rate variability, galvanic skin responses, or pupillometry among children or adolescents with a chronic pain condition. Studies examining these factors in the context of a specific disease-related pain condition were excluded.

RESULTS

Of the 1304 articles screened, 15 studies met the criteria for inclusion in this review. All included studies were cross-sectional and primarily included youth with abdominal pain. Results revealed preliminary evidence of reduced parasympathetic activity among youth with pain as measured by heart rate variability. However, results were mixed across ANS indices. Measurement and procedural differences, in addition to a lack of control groups in some studies, limit the interpretability of the reviewed findings.

DISCUSSION

Additional studies with larger and more diverse samples of youth with various chronic primary pain conditions are needed to delineate possible relationships among ANS functioning and the development and maintenance of chronic pain in children and adolescents. Clinical implications and avenues for future research are discussed.

Meta-analysis of the effectiveness of the Trier Social Stress Test in eliciting physiological stress responses in children and adolescents

The Trier Social Stress Test (TSST) is known to reliably induce physiological stress responses in adult samples. Less is known about its effectiveness to elicit these responses in youth samples. We performed a meta-analysis of stress responses to the TSST in youth participants. Fifty-seven studies were included representing 5026 youth participants. Results indicated that the TSST was effective at eliciting stress responses for salivary cortisol (sCort; effect size [ES] = 0.47, p = 0.006), heart rate (HR; ES = 0.89, p < 0.001), pre-ejection period (PEP; ES = -0.37, p < 0.001), heart rate variability (HRV; ES = -0.33, p = 0.028), and systolic blood pressure (ES = 1.17, p < 0.001), as well as negative affect (ES = 0.57, p = 0.004) and subjective anxiety (ES = 0.80, p = 0.004) in youth samples. Cardiac output (ES = 0.15, p = 0.164), respiratory sinus arrhythmia (ES = -0.10, p = 0.064), and diastolic blood pressure (ES = 2.36, p = 0.072) did not reach statistical significance. Overall, effect sizes for the TSST varied based on the physiological marker used. In addition, several physiological markers demonstrated variance in reactivity by youth age (sCort, HR, HRV, and PEP), gender (sCort), type of sample (i.e., clinical versus community sample; sCort and HR), duration of TSST (sCort, HR, HRV, negative affect, and subjective anxiety), number of judges present in TSST (HR and subjective anxiety), gender of judges (sCort), and time of day the marker was assessed (morning versus afternoon/evening; sCort). Overall, the findings provide support for the validity of the TSST as a psychosocial stressor for inducing physiological and psychological stress responses in children and adolescents, but also highlight that some markers may capture the stress response more effectively than others.

Interoceptive Abilities in Inflammatory Bowel Diseases and Irritable Bowel Syndrome

Alexithymia is usually described by three main dimensions difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and externally oriented thinking (EOT). The most commonly used questionnaire investigating alexithymia, the Toronto Alexithymia Scale (TAS-20), supports this three-factor structure. One important assumption is that alexithymia severity is associated to vulnerability to somatic diseases, among them gastrointestinal disorders. However, the association between alexithymia and gastrointestinal disorders is not systematic, thus questioning the role of alexithymia as a vulnerability factor for those illnesses. A recent factor analysis suggested another four-factor structure for the TAS-20: difficulties in awareness of feelings (DAF), difficulties in interoceptive abilities (DIA), externally oriented thinking (EOT), and poor affective sharing (PAS). We assume that DIA and DAF might be more relevant to investigate the association between alexithymia and gastrointestinal disorders. The rationale is that DIA and DAF reflect impairments in emotion regulation that could contribute to an inappropriate autonomic and HPA axis homeostasis in irritable bowel syndrome (IBS), ulcerative colitis (UC), or Crohn's disease (CD). The aim of this study was to investigate whether DIA and DAF are associated with the presence of IBS, UC or CD, while checking for anxiety, depression, parasympathetic (vagus nerve) activity and cortisol levels. We recruited control participants (n=26), and patients in remission who were diagnosed with IBS (n=24), UC (n=18), or CD (n=21). Participants completed questionnaires to assess anxiety, depression, and alexithymia. A blood sample and an electrocardiogram were used to measure the level of cortisol and parasympathetic activity, respectively. Logistic regressions with the four-factor structure of the TAS-20 revealed that DIA was a significant predictor of IBS (W(1)=6.27, p=.01). Conversely, DIA and DAF were not significant predictors in CD and UC patients. However, low cortisol level was a significant predictor of UC (W(1)=4.67, p=.035). Additional logistic regressions based on the original 3-factor structure of TAS-20 (DIF, DDF, and EOT) showed that only DDF was a significant predictor of CD [W(1)=6.16, p < .001]. The present study suggests that DIA is an important dimension for assessing potential risk for gastrointestinal diseases, in particular for IBS.

Stress-system activation in children with chronic pain: A focus for clinical intervention

Accumulating evidence indicates that psychological and neurophysiological processes interconnect and interact to activate the body's stress system and to trigger and maintain functional somatic symptoms. This study used the Early Life Stress Questionnaire, Depression Anxiety Stress Scales and biological markers (heart rate, heart rate variability, skin conductance, C-reactive protein (CRP) titre, respiratory rate, and accuracy and reaction time in an emotion-face identification task), to examine childhood adversity, psychological distress and stress-system activation in 35 children and adolescents (23 girls and 12 boys, 9-17 years old) disabled by chronic pain (vs two groups of age- and sex-matched healthy controls). Patients reported more early-life stress (U = 798.5, p = .026) and more psychological distress (U = 978, p < .001). They showed activation of the autonomic system: elevated heart rate (U = 862.5, p = .003), elevated electrodermal activity (U = 804.5, p = .024) and lower heart rate variability in the time domain (U = 380.5, p = .007) and frequency domain (U = 409.5, p = .017). The group showed an upward shift of CRP titres (with 75th and 90th CRP percentiles of 4.5 and 10.5 mg/L, respectively), suggesting the activation of the immune-inflammatory system. Elevated CRP titres were associated with elevated heart rate (p = .028). There were no differences in respiratory rate or in accuracy and reaction time in the emotion-face identification task. The results indicate that interventions for children and adolescents with chronic pain need a multidisciplinary mind-body approach that concurrently addresses psychological distress, physical impairment and stress-system dysregulation.

Wired for Threat: Clinical Features of Nervous System Dysregulation in 80 Children

BACKGROUND

The negative effect of perceived stress on health has become a cultural epidemic. Despite many health implications, the clinical impact of stress on the nervous system is not well understood. This case series describes the symptom profiles of 80 children with nervous system dysregulation attributed to maladaptive neuroendocrine responses to stress.

METHODS

We reviewed of 80 children with nervous system dysregulation identified from a single, tertiary care pediatric neurology clinic. Included patients were between five and 17 years of age, with unexplained medical symptoms lasting three months or longer affecting at least four of six neurological domains: (1) somatization, (2) executive function, (3) autonomic function, (4) digestion, (5) sleep, and (6) emotional regulation. Medical symptoms, diagnoses, and detailed social histories were collected.

RESULTS

Of 80 children, 57 were female (71%), 57 were Caucasian (71%), with median age of 14 years. Symptoms had a mean duration of 32 months, and included: 100% somatic symptoms, 100% emotional dysregulation, 92.5% disrupted sleep, 82.5% autonomic dysregulation, 75% executive dysfunction, and 66% digestive problems. Overall, 94% reported chronic or traumatic stressors; adverse childhood experiences were present in 65%.

CONCLUSIONS

Perceived stress impacts many functions of the neuroendocrine system through experience-dependent plasticity, resulting in a constellation of symptoms and functional impairments we describe as nervous system dysregulation. The pathophysiology of these symptoms involves dysregulation of subcortical, hormonal, and autonomic circuits, which remain largely untested. Recognition and understanding of maladaptive neurophysiology in stress-related symptoms has important implications for diagnosis, treatment, and advances in health research.

Using the child behavior checklist to determine associations between psychosocial aspects and TMD-related pain in children and adolescents

BACKGROUND

Since children and adolescents are frequently experiencing emotional and behavioral consequences due to pain, their parents should be aware of this emotional and behavioral status. Therefore, the aim of this study was to analyze and describe the parents' reports of the emotional and behavioral status of children and adolescents with different types of temporomandibular disorders using the Child Behavior Checklist.

METHODS

This Cross-sectional study comprises of 386 randomly selected children and adolescents that ages between 10 and 18 years in Jeddah. One day prior the clinical examination according to Research Diagnostic Criteria for temporomandibular disorders (TMD) Axis I and II, Arabic version of the Child Behavior Checklist scale was distributed to the parents of participant. According to the diagnosis, the participants were divided into three groups; non-TMD group, TMD-pain group, and TMD-painfree group.

RESULTS

In regard to internalizing problems, the parents to the children and adolescents in the TMD-pain group rated a higher frequency of anxiety, depression and somatic complaints in their children than the parents of children in the non-TMD group (p < 0.05). Only one significant association regarding the externalizing problems was found for the aggressive behavior in the TMD-pain group.

CONCLUSION

The parents rated that their children with TMD-pain suffer from emotional, somatic and aggressive behavior to a higher degree than healthy control subjects. Also, the parents believed that TMD-pain influenced their children's physical activities but not social activities.

Pediatric abdominal migraine: current perspectives on a lesser known entity

Background

Abdominal migraine (AM) is a common cause of chronic and recurrent abdominal pain in children. It is characterized by paroxysms of moderate to severe abdominal pain that is midline, periumbilical, or diffuse in location and accompanied by other symptoms including headache, anorexia, nausea, vomiting, or pallor. Despite the presence of comprehensive diagnostic criteria under Rome IV classification of functional gastrointestinal disorders (FGIDs) and International Classification of Headache Disorders, it continues to be an underdiagnosed entity.

Overview

The average age of diagnosis is 3–10 years with peak incidence at 7 years. Most of the patients have a personal or family history of migraine. Pathophysiology of the condition is believed to be similar to that of other FGIDs and cephalic migraine. It is also well recognized as a type of pediatric migraine variant. A careful history, thorough physical examination, and use of well-defined, symptom-based guidelines are needed to make a diagnosis. Selective or no testing is required to support a positive diagnosis. It resolves completely in most of the patients. However, these patients have a strong propensity to develop migraine later in life. Explanation and reassurance should be the first step once the diagnosis is made. Nonpharmacologic treatment options including avoidance of triggers, behavior therapy, and dietary modifications should be the initial line of management. Drug therapy should be considered only if symptoms are refractory to these primary interventions.

Conclusion

More research focused on pathophysiology and management of AM needs to be carried out to improve outcomes in affected children.

Preliminary evidence for increased parasympathetic activity during social inclusion and exclusion in adolescents with functional abdominal pain

OBJECTIVE

Peer victimization (e.g. social exclusion) has been shown to be associated with physical health problems such as functional somatic complaints and especially symptoms of pain. To date, no study has investigated the mechanisms underlying this association in clinical pediatric samples. The aim of this study was to evaluate the parasympathetic activity during a social exclusion experience in adolescents with functional abdominal pain (FAP).

METHODS

Twenty adolecents with FAP and 21 matched healthy participants were compared regarding parameters of parasympathetic activation before, during, and after participating in the Cyberball-game, a well-established paradigm to induce social exclusion.

RESULTS

Adolescents with FAP showed an increase in parasympathetic activation during both consecutive phases of the Cyberball game (inclusion as well as exclusion condition) whereas the healthy control group remained stable. There were no differences in subjective experience of in- and exclusion between the groups.

CONCLUSION

The parasympathetic activation pattern may indicate altered processing of social stimuli in adolescents with FAP.