Looking at allergens increases symptom report in patients with allergic asthma.

OBJECTIVE: Accurate symptom perception is highly important for self-management and clinical treatment of asthma. Recent findings suggest that psychological factors can greatly impact asthma symptom perception. This study examined whether looking at allergens would lead to changes in perceived asthma symptoms. METHODS: Allergic asthma patients and healthy controls viewed picture series containing either allergens or neutral material. Symptom reports and respiratory parameters were measured. RESULTS: The present results demonstrate that looking at pictures with allergens increases subjective symptom reports in patients with allergic asthma in the absence of changes in objective respiratory parameters, but not in healthy controls. CONCLUSIONS: The results are suggestive of preceding learning processes during which patients have learned the association between visual representations of allergens and symptom-inducing effects of real contact with these allergens. This impacts asthma symptom perception without changes in respiratory status and might influence treatment decisions.

Down-regulation of insular cortex responses to dyspnea and pain in asthma.

RATIONALE: Dyspnea is the impairing cardinal symptom of asthma but its accurate perception is also crucial for timely initiation of treatment. However, the underlying brain mechanisms of perceived dyspnea in patients with asthma are unknown. OBJECTIVES: To study brain mechanisms of dyspnea in asthma. METHODS: By using functional magnetic resonance imaging we compared the neuronal responses to experimentally induced dyspnea in patients with asthma and healthy controls. These brain activations were compared with neuronal responses evoked by pain to study neuronal generalization processes to another, similarly unpleasant, physiological sensation. MEASUREMENTS AND MAIN RESULTS: While lying in the scanner, fourteen patients with mild-to-moderate asthma and fourteen matched healthy controls repeatedly underwent conditions of mild dyspnea, severe dyspnea, mild pain and severe pain. Dyspnea was induced by resistive loaded breathing. Heat pain of similar intensity was induced by a contact thermode. Whereas the sensory intensity of both sensations was rated similar by patients and controls, ratings of the affective unpleasantness of dyspnea and pain were reduced in patients. This perceptual difference was mirrored by reduced insular cortex activity, but increased activity in the periaqueductal gray (PAG) in patients during both increased dyspnea and pain. Connectivity analyses showed that asthma-specific down-regulation of the insular cortex during dyspnea and pain was moderated by increased PAG activity. CONCLUSIONS: The results suggest a down-regulation of affect-related insular cortex activity by the PAG during perceived dyspnea and pain in patients with asthma. This might represent a neuronal habituation mechanism reducing the affective unpleasantness of dyspnea in asthma, which generalizes to other unpleasant physiological sensations such as pain.

Dyspnea and pain share emotion-related brain network.

The early detection of stimuli signalling threat to an organism is a crucial evolutionary advantage. For example, the perception of aversive bodily sensations such as dyspnea and pain strongly motivates fast adaptive behaviour to ensure survival. Their similarly threatening and motivating characters led to the speculation that both sensations are mediated by common brain areas, which has also been suggested by neuroimaging studies on either dyspnea or pain. By using functional magnetic resonance imaging (fMRI), we formally tested this hypothesis and compared the cortical processing of perceived heat pain and resistive load induced dyspnea in the same group of participants. Here we show that the perception of both aversive sensations is processed in similar brain areas including the insula, dorsal anterior cingulate cortex, amygdala and medial thalamus. These areas have a documented role in the processing of emotions such as fear and anxiety. Thus, the current study highlights the role of a common emotion-related human brain network which underlies the perception of aversive bodily sensations such as dyspnea and pain. This network seems crucial for translating the threatening character of different bodily signals into behavioural consequences that promote survival.

Reduced perception of dyspnea and pain after right insular cortex lesions.

RATIONALE: The perception of dyspnea and pain show many similarities. Initial imaging studies suggested an important role of the insular cortex for the perception of both sensations. However, little is known about the cortical processing of dyspnea. OBJECTIVES: This study investigated the influence of lesions of the insular cortex on the perception of dyspnea and pain. METHODS: Dyspnea was induced by resistive loaded breathing in four patients with right-hemispheric insular cortex lesions, as assessed with computer tomography or magnetic resonance imaging, and four matched healthy control subjects. Pain was induced by a cold-pressor test. Perceived intensity and unpleasantness of both sensations were rated on visual analog scales. MEASUREMENTS AND MAIN RESULTS: In contrast to healthy control subjects, patients with lesions demonstrated reduced perceptual sensitivity for dyspnea, in particular for the unpleasantness of dyspnea (P < 0.05). This was paralleled by reduced sensitivity for pain in patients with lesions, as reflected by smaller ratings of intensity and unpleasantness, higher sensory pain-thresholds, and, in particular, higher affect-related pain tolerance times (P < 0.05). CONCLUSIONS: The results suggest that lesions of the right insular cortex are associated with reduced sensitivity for the perception of dyspnea and pain, in particular for their perceived unpleasantness. This underlines the importance of the insular cortex for the perception of both sensations.

The unpleasantness of perceived dyspnea is processed in the anterior insula and amygdala.

RATIONALE: The subjective perception of dyspnea, which is an impairing symptom in various cardiopulmonary diseases, consists of sensory (intensity) and affective aspects (unpleasantness). However, little is known about the cortical processing of the perception of dyspnea. OBJECTIVES: To investigate the cortical areas associated with the processing of the affective unpleasantness of perceived dyspnea. METHODS: Brain imaging study using functional magnetic resonance imaging in 14 healthy volunteers. MEASUREMENTS AND MAIN RESULTS: Dyspnea was induced by inspiratory resistive loaded breathing with concomitant positive and negative emotional stimulation by viewing standardized emotional picture series. The blood oxygen level-dependent contrast was measured as an index of local neuronal activity while respiration was continuously monitored. Negative emotional stimulation during loaded breathing was associated with higher unpleasantness of perceived dyspnea when compared with loaded breathing with concomitant positive emotional stimulation (P < 0.05). The levels of intensity of perceived dyspnea, respiratory responses, and load magnitude were similar between both conditions. Higher unpleasantness of dyspnea was associated with neuronal activations in the limbic system-that is, in the right anterior insula and in the right amygdala (respective Z values = 3.93 and 3.15; P < 0.05). CONCLUSIONS: The results of the present brain imaging study suggest that the unpleasantness of subjectively perceived dyspnea is processed in the right human anterior insula and amygdala.

A MATLAB toolbox for correcting within-individual effects of respiration rate and tidal volume on respiratory sinus arrhythmia during variable breathing.

Respiratory sinus arrhythmia (RSA) is a common estimator of vagal outflow to the heart, dependent on parasympathetic activity. During variable breathing, both respiration rate and tidal volume contribute substantially to within-individual RSA variance. A respiratory control method allows for within-individual correction of the time-domain index of RSA. rsaToolbox is a set of MATLAB programs for scoring respiration-corrected RSA using measurements of cardiac interbeat intervals, respiratory-cycle times, and tidal volumes, recorded at different paced-breathing frequencies. The within-individual regression of RSA divided by tidal volume upon total respiratory cycle time is then used to estimate the baseline vagal tone for each breath of a given total respiratory-cycle time. During a subsequent analysis, the difference between the observed RSA (divided by the tidal volume at each breath) and the RSA divided by the tidal volume that was predicted by the baseline equation serves as an estimate of changes in vagal tone. rsaToolbox includes a graphical user interface for intuitive handling. Modular implementation of the algorithm also allows for flexible integration within other analytic strategies or for batch processing.

The evaluation of supervision: construction of brief questionnaires for the supervisor and the supervisee.

This study evaluated the psychometric properties of two parallel questionnaires (for the supervisor and supervisee, respectively). Ninety supervisees and 37 supervisors from different parts of Germany took part in the study. The three dimensions of clarifying, problem solving, and relationship were confirmed, but for both supervisor and supervisee versions of the scale medium intercorrelations also allowed a combined scale to be formed. In exploratory regression analysis, the relationship dimension related to both perspectives (i.e., supervisor and supervisee) served as the best predictor for overall supervision satisfaction. Despite the fact that general session satisfaction correlated in the medium range between supervisor and supervisee, there was no correlation between the perspectives as measured by the questionnaires. Possible reasons for this unexpected correlational pattern are discussed.

Stress effects on lung function in asthma are mediated by changes in airway inflammation.

OBJECTIVE: To examine the association of changes in current negative mood and long-term daily hassles with changes in lung function and airway inflammation in patients suffering from asthma and in healthy controls. Associations between psychological factors and asthma symptoms have been documented, but the relationship between airway inflammation and psychological factors has been largely unexplored. METHOD: Data were analyzed from 46 asthma patients and 25 controls who completed questionnaires on current mood and daily hassles at two assessments 3 months apart. Lung function was measured by spirometry (forced expiratory volume in the first second (FEV(1))) and airway inflammation by the fraction of nitric oxide in exhaled air (FeNO). Regression analyses controlling for allergen load and air pollution (ozone) were calculated to study the association between changes in psychological factors and changes in lung function and airway inflammation, and to examine the mediational role of airway inflammation in the stress-lung function association. RESULTS: In patients with asthma, increases in negative affect were associated with decreases in FEV(1) and increases in FeNO. For daily hassles, a reverse pattern of associations was found, with decreases in daily hassles linked to decreases in FEV(1) and increases in FeNO. Mediation analyses showed that FeNO was a significant mediator of the association of both negative affect and daily hassles with lung function changes. No significant associations were found for healthy controls. CONCLUSION: Psychological variables are consistently associated with spirometric lung function and airway inflammation in asthma patients. For asthma patients, effects of acute negative affect must be distinguished from more chronic distress due to daily hassles.

Perceived triggers of asthma: evaluation of a German version of the Asthma Trigger Inventory.

BACKGROUND AND OBJECTIVE: Patients' perception of asthma triggers has been explored in a largely unstructured fashion in the past. Therefore, we developed the Asthma Trigger Inventory (ATI), a questionnaire that allows for a psychometrically valid measurement of patients' perceived asthma triggers. Here we evaluate a German language version of the ATI and studied the relationship of subscales with self-reported health status, health care use, psychopathology, and results of allergy skin testing. METHOD: Data were obtained from 370 asthma patients recruited from the community, primary care, and in-patient asthma treatment and education. RESULTS: Analysis revealed a five-factor structure that largely confirmed results with the English original. Reliability was good to satisfactory (Cronbach's alpha=0.77-0.89) for allergy, exercise, air pollution/irritants, infection, and psychological trigger subscales. In hierarchical regression analysis adjusting for demographics and asthma severity, asthma patients with stronger non-allergic triggers showed less physical and mental well-being and more asthma-related health care use. Psychological triggers showed unique associations with anxious and depressed mood. Pollen and animal allergen scores of the ATI were significantly related to skin test results for relevant allergens. Non-allergic but not allergic triggers showed substantial associations with asthma control. CONCLUSION: The German version of the ATI reliably measures asthma patients' trigger perceptions. Non-specific asthma triggers exert a greater burden on patients' well-being and primary health care use.

Distractive auditory stimuli reduce the unpleasantness of dyspnea during exercise in patients with COPD.

BACKGROUND: Dyspnea is the primary symptom limiting exercise in patients with COPD. Recent research has demonstrated that psychological factors can substantially influence the perception of dyspnea, but little is known about the modulation of perceived intensity or unpleasantness of dyspnea by attentional distraction. Therefore, we examined the impact of distractive auditory stimuli on the perception of exercise-induced dyspnea and the affective state in patients with COPD during 6-min walking tests (6MWTs). METHODS: Twenty patients with mild-to-severe COPD (mean FEV1, 55.9% predicted) underwent two 6MWTs. Under one exercise condition, distractive auditory stimuli were presented with headphones, while the other condition was performed without auditory distraction. Lung function (FEV1), heart rate (HR), pulse oximetric saturation (SpO2), perceived intensity of dyspnea (ie, visual analog scale for perceived intensity of dyspnea [VAS-I]), and perceived unpleasantness of dyspnea (visual analog scale for perceived unpleasantness of dyspnea [VAS-U]) were measured before and after exercise. In addition, the global level of dyspnea (Borg score), positive affectivity (PA), and negative affectivity were assessed after both conditions. RESULTS: A similar exercise level during both conditions was confirmed by comparable results in FEV1, HR, SpO2, and distances walked. During auditory distraction, Borg scores and increases in VAS-U were smaller, while PA was higher compared to the nondistraction condition (p<0.05). VAS-I did not show differences across conditions. CONCLUSIONS: Distractive auditory stimuli decrease the global level of exercise-induced dyspnea in patients with COPD by reducing the perceived unpleasantness of dyspnea and lead to an additional increase in PA. Auditory distraction might therefore serve as an intervention for the reduction of dyspnea during exercise in this patient group.

Verbal descriptors of dyspnea in patients with COPD at different intensity levels of dyspnea.

BACKGROUND: Verbal descriptors of dyspnea are important in understanding the underlying mechanisms, but little is known about the language of dyspnea in COPD. We examined the language of dyspnea in COPD at different intensity levels of dyspnea. METHODS: Verbal descriptors of dyspnea were assessed in 64 patients with moderate-to-severe COPD (mean age, 62 years; mean percentage of predicted FEV(1) [FEV(1)%pred], 54.1%) during slight dyspnea at rest (mean Borg score, 1.8), moderate dyspnea during cycle ergometer exercise (mean Borg score, 3.1) and somewhat severe dyspnea during a 6-min walking test before (mean Borg score, 4.2), and after pulmonary rehabilitation (PR) [mean Borg score, 3.5]. Furthermore, the influence of age, gender, baseline lung function (FEV(1)%pred), and PR on the verbal descriptors were studied. RESULTS: A cluster analysis showed that patients differentiated between five clusters of verbal descriptors of dyspnea: heavy/fast breathing, shallow breathing, obstruction, work/effort, and suffocation. These were related to the intensity level of dyspnea but not to age, gender, baseline lung function, or PR. While shallow breathing was predominant only during slight dyspnea at rest, heavy/fast breathing and to a lesser extent work/effort became more important during moderate and somewhat severe dyspnea during exercise. The clusters heavy/fast breathing and work/effort demonstrated the highest sensitivity in discriminating between different intensity levels of dyspnea and in characterizing the positive effects of PR. CONCLUSIONS: Verbal descriptors of dyspnea in COPD are related to the intensity level of dyspnea. The clusters heavy/fast breathing and work/effort seem to be particularly sensitive descriptors of dyspnea during exercise in COPD.

Psychological aspects in the perception of dyspnea in obstructive pulmonary diseases.

Dyspnea is an impairing symptom in obstructive pulmonary diseases. Besides multiple physiological pathways contributing to this sensation recent research has demonstrated an important role of psychological factors in the perception of dyspnea. The present review article synthesizes the research literature with regard to psychological aspects of the perception of dyspnea as well as other dyspnea-related issues such as course of disease, neuropsychological correlates and interventions that focus on psychological or behavioural changes. The available data show that inaccurate perception of dyspnea is related to poorer treatment outcome in obstructive pulmonary diseases and is impacted upon by emotional, attentional and learning processes. Neuropsychological deficits might further contribute to this association. Different psychological and behavioural interventions might reduce comorbid psychological disorders and thus improve the perception of dyspnea. However, future research is clearly required to substantiate current findings.

The influence of corticosteroids on the perception of dyspnea in asthma.

Corticosteroids are effective anti-inflammatory medications that are recommended for the control of persistent asthma. Little, however, is known about their influence on the perception of dyspnea, which, in turn, is important to the successful self-management of asthma. This paper provides a synopsis of available studies examining the impact of corticosteroids on the sensitivity to perceive dyspnea and presents possible mechanisms underlying this relationship. The results of these investigations are conflicting with some studies showing improved perception and other studies showing worsened perception of dyspnea after corticosteroid treatment. Thus, firm conclusions cannot be derived from the currently available data. Implications for future research, which is required to increase our understanding of potential influences of corticosteroids on the perception of dyspnea, are provided.

Attentional distraction reduces the affective but not the sensory dimension of perceived dyspnea.

The perception of dyspnea shows many similarities to the perception of pain. Both are multidimensional processes, which are not only influenced by sensory input but also by nonsensory factors like attention. Recent research has suggested that attentional distraction might reduce the perception of dyspnea but results are conflicting. Furthermore, the specific impact of attentional distraction on the distinct dimensions of perceived dyspnea has not been studied yet. Therefore, the present study examined the specific impact of changes in the attentional focus on the sensory and affective dimension of perceived dyspnea. Dyspnea was induced in forty-four healthy volunteers (mean age: 27.7 years, range: 18-47 years) by breathing through an inspiratory resistive load (3.57 kPa/L/s), while attention was directed either to breathing or distracted by reading texts. Inspiratory time (T(i)) and breathing frequency (f) were measured continuously. After each condition the experienced intensity (i.e., sensory dimension) and unpleasantness (i.e., affective dimension) of dyspnea were rated on separate visual analog scales (VAS), presented in randomized order. ANOVAs showed that attentional distraction during loaded breathing reduced the perceived unpleasantness of dyspnea (P<0.05), while the perceived intensity of dyspnea as well as T(i) and f remained unchanged. The results show that attentional distraction reduces the affective, but not the sensory dimension of induced dyspnea in healthy volunteers. Future studies are needed to clarify whether attentional distraction can effectively be used as intervention technique for reducing the unpleasant aspects of dyspnea in different patients groups.

Association of depression and anxiety with health care use and quality of life in asthma patients.

INTRODUCTION: Demographic factors, symptom severity, and psychopathology, in particular anxiety and depression, are known to influence health care use and quality of life in asthma. Because depression and anxiety are typically correlated, we sought to explore whether depression specifically is associated with health care utilization and quality of life when effects of anxiety are controlled for. METHOD: In a cross-sectional questionnaire study, 88 asthma patients (46 women; age range 27-70 years) reported on symptoms and treatment of their disease, as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS), general quality of life (Short Form 12 Health Survey Questionnaire, SF-12) and asthmatic-specific quality of life (Living with Asthma, LAQ). RESULTS: While no considerable associations between anxiety and health care use were found, the associations between higher scores in depression and hospital visits as well as days of corticosteroid intake were significant. Furthermore, considerable variance in all subscales of quality of life questionnaires was explained by higher scores in depression, even when controlling for anxiety. For anxiety scores these associations were comparable, except for physical well-being. CONCLUSION: Depression is an important issue in asthma, as it is substantially related to quality of life and intake of corticosteroids, and marginally to hospitalization. Routine screening for depression should be considered in hospital and primary care.

Implementation and interpretation of respiratory sinus arrhythmia measures in psychosomatic medicine: practice against better evidence?

Respiratory sinus arrhythmia (RSA) or high-frequency heart rate variability has been widely used as a noninvasive measure of cardiac vagal tone. However, their dependency on both respiration rate and tidal volume is largely ignored. Only a minority of studies published in Psychosomatic Medicine in recent years has implemented precautions for controlling respiration rate in RSA measures, and tidal volume effects were only rarely addressed. We discuss methodologic issues related to respiratory control methods and present data that demonstrate that both respiration rate and tidal volume contribute substantially to the within-individual RSA variance under conditions of variable breathing, with tidal volume contributing up to one third beyond respiration rate. Finally, we outline a respiratory control method for the time-domain index of RSA and review research pertaining to its reliability, validity, and experimental application.

Emotions and respiratory function in asthma: a comparison of findings in everyday life and laboratory.

OBJECTIVES: The present study examined the influence of emotions on the respiratory function in asthmatic and non-asthmatic individuals in everyday life and the relationship to emotion-induced respiratory changes in the laboratory. METHODS: Affective states were induced in 10 asthmatic and 10 non-asthmatic participants by viewing affective picture series of either a pleasant, neutral, or unpleasant valence, while airway resistance (Raw) was measured with whole body plethysmography. Following this, individuals measured their mood, forced expiratory volume in the first second (FEV1), peak expiratory flow (PEF), physical activity, and medication use for 21 days with an electronic diary, which included a respiratory self-measurement device. Strong pleasant and unpleasant mood episodes were extracted from the diaries and compared with neutral affective states. RESULTS: Asthmatic patients showed increases of Raw after unpleasant and pleasant emotional stimulation in the laboratory, which was only found after a pleasant stimulation in non-asthmatic participants. In everyday life, no group differences were obtained. Episodes of strong unpleasant mood states were associated with decreases in PEF, whereas in contrast to the laboratory assessment, pleasant mood was associated with increases in PEF. Results for FEV1 were comparable, but non-significant. Physical activity and medication use did not vary systematically between affective episodes. PEF showed no significant relationship with Raw. CONCLUSIONS: Unpleasant mood is associated with decreased respiratory function in asthmatic patients in everyday life and in laboratory assessments, whereas effects of pleasant mood states are inconsistent. Pulmonary responses to laboratory-induced emotional conditions are not predictive of airways reactivity during daily life.

Cortical substrates for the perception of dyspnea.

Dyspnea is a common, unpleasant, and impairing symptom in various respiratory diseases and other diseases. Despite growing understanding of the multiple peripheral mechanisms giving rise to dyspnea, little is known about the cortical mechanisms underlying its perception. The results of neuroimaging studies have shown that distinct brain areas process the dyspneic sensation, among which the anterior insular seems to be the most important. Based on the findings of the first relevant neuroimaging studies, this review describes the cortical structures associated with the perception of dyspnea. Moreover, similarities to the perception of pain are discussed, and implications for future research are provided.

Differentiation between the sensory and affective dimension of dyspnea during resistive load breathing in normal subjects.

STUDY OBJECTIVE: Dyspnea is the uncomfortable sensation of breathing and is an impairing symptom in a variety of diseases. Like pain, it motivates adaptive behavior to regain homeostasis, and both sensations share various characteristics. Whereas the realization of the multidimensionality of pain was a key contribution to pain research, little is known about a similar multidimensionality in the perception of dyspnea. The present study examined whether sensory and affective aspects of induced dyspnea can be differentiated. DESIGN: A controlled laboratory study. SETTING: Psychophysiologic laboratory of the Psychological Institute III, University of Hamburg, Germany. PARTICIPANTS: Ten healthy volunteers aged 24 to 52 years (mean, 35 years). INTERVENTIONS: Dyspnea was induced by breathing through inspiratory resistive loads of increasing magnitude (0.99 to 2.33 kPa/L/s), alternating with episodes of unloaded breathing. Inspiratory time (Ti) and breathing frequency (f) were continuously monitored. The experienced intensity and unpleasantness of dyspnea were rated after each episode on separate visual analog scales (VASs), which were presented in permuted order. Intraindividual linear regression slopes were calculated separately for both dimensions and compared. MEASUREMENTS AND RESULTS: Breathing through inspiratory resistive loads resulted in increases of VAS ratings for intensity and unpleasantness paralleled by increases in Ti and decreases in f (p = 0.012 and p = 0.003, respectively). The mean regression slope for perceived unpleasantness was higher than for perceived intensity (mean +/- SD, 2.83 +/- 1.28 and 2.11 +/- 1.74, respectively; p = 0.032), indicating stronger increases of unpleasantness with increasing magnitude of resistive loads. CONCLUSIONS: The results show that the sensory and affective dimension of experimentally induced dyspnea can be differentiated in healthy volunteers. The obtained multidimensionality of dyspnea converges with previous reports on similarities between dyspnea and pain. Implications for future studies on the perception of dyspnea are provided.

Self-injurious behavior in women with eating disorders.

OBJECTIVE: The authors assessed lifetime and 6-month occurrence and phenomenology of self-injurious behavior in patients with eating disorders. METHOD: Women (N=376) in inpatient treatment for an eating disorder (anorexia: N=119, bulimia: N=137, eating disorder not otherwise specified: N=120) were assessed for self-injurious behavior and completed the Traumatic Life Events Questionnaire, the Dissociative Experience Scale, the Barratt Impulsiveness Scale, and the Yale-Brown Obsessive Compulsive Scale. RESULTS: The lifetime rate of self-injurious behavior occurrence was 34.6%, with the highest rates found in subjects with eating disorder not otherwise specified (35.8%) and bulimia (34.3%); the 6-month rate of self-injurious behavior occurrence was 21.3%. Multivariate comparisons were computed for the factors of self-injurious behavior and diagnostic subgroup: self-injuring patients reported a significantly higher number of traumatic events, showed significantly higher dissociation scores, and exhibited significantly more obsessive-compulsive thoughts and behaviors. Bulimic patients showed significantly higher impulsivity scores. CONCLUSIONS: This study strongly supports the assumption that patients with eating disorders are at risk for self-injurious behavior and points to the necessity of a routine screening for self-injurious behavior as well as the development of a standardized questionnaire. Group comparisons point to the relevance of traumatic experiences and comorbid dissociative phenomenology.