The impact of emotions on the perception of dyspnea in pediatric asthma

The Interactive Effects of Post-Traumatic Stress Symptoms and Breathlessness on Fatigue Severity in Post-COVID-19 Syndrome

Background: Post-traumatic stress symptoms (PTSS) and breathlessness have been well documented in the acute phase of COVID-19 as well as in Post-COVID-19 Syndrome (PCS), commonly known as Long-COVID. The present study aimed to explore whether PTSS and breathlessness interact to exacerbate fatigue among individuals recovering from PCS, similar to the effects evidenced in other health conditions that feature respiratory distress.. Methods: Outcome measures were collected from 154 participants reporting persistent fatigue following acute COVID-19 infection who were enrolled in a 7-week rehabilitation course provided by the Primary Care Wellbeing Service (PCWBS) in Bradford District Care NHS Foundation Trust (BDCFT). Results: Hierarchical multiple linear regression revealed that fatigue severity was associated with a significant interaction between PTSS and breathlessness, even when controlling for pre-COVID health related quality of life (HRQoL), age, symptom duration and hospital admittance during the acute phase. Furthermore, improvements in fatigue following rehabilitation were significantly associated with improvements in PTSS. Conclusions: PTSS may be an important therapeutic target in multidisciplinary rehabilitation for reducing fatigue in the recovery from PCS. It is therefore important that treatment for PCS takes a biopsychosocial approach to recovery, putting emphasis on direct and indirect psychological factors which may facilitate or disrupt physical recovery. This highlights the need for all PCS clinics to screen for PTSD and if present, target as a priority in treatment to maximise the potential for successful rehabilitation.

Time series analysis of intensive longitudinal data in psychosomatic research: A methodological overview

Time series analysis of intensive longitudinal data provides the psychological literature with a powerful tool for assessing how psychological processes evolve through time. Recent applications in the field of psychosomatic research have provided insights into the dynamical nature of the relationship between somatic symptoms, physiological measures, and emotional states. These promising results highlight the intrinsic value of employing time series analysis, although application comes with some important challenges. This paper aims to present an approachable, non-technical overview of the state of the art on these challenges and the solutions that have been proposed, with emphasis on application towards psychosomatic hypotheses. Specifically, we elaborate on issues related to measurement intervals, the number and nature of the variables used in the analysis, modeling stable and changing processes, concurrent relationships, and extending time series analysis to incorporate the data of multiple individuals. We also briefly discuss some general modeling issues, such as lag-specification, sample size and time series length, and the role of measurement errors. We hope to arm applied researchers with an overview from which to select appropriate techniques from the ever growing variety of time series analysis approaches.

An Anti-hyperventilation Instruction Decreases the Drop in End-tidal CO2 and Symptoms of Hyperventilation During Breathing at 0.1 Hz

Breathing at a frequency of around 0.1 Hz is widely used in basic research and in applied psychophysiology because it strongly increases fluctuations in the cardiovascular system and affects psychological functioning. Volitional control of breathing often leads to hyperventilation among untrained individuals, which may produce aversive symptoms and alter the psychological and physiological effects of the paced breathing. The present study investigated the effectiveness of a brief anti-hyperventilation instruction during paced breathing at a frequency of 0.1 Hz. Forty-six participants were randomly assigned to one of two groups: a group given an anti-hyperventilation instruction and a control group without such an instruction. The instruction asked participants to avoid excessively deep breathing and to breathe shallowly and naturally. Participants performed the breathing task for 10 min. Hyperventilation was measured by partial pressure of end-tidal CO₂ (PetCO₂); furthermore, symptoms of hyperventilation, feeling of air hunger, task difficulty, and affective state were measured by self-report. The results showed that paced breathing without instruction decreased PetCO₂ by 5.21 mmHg and that the use of the anti-hyperventilation instruction reduced the drop in PetCO₂ to 2.7 mmHg. Symptoms of hyperventilation were lower in the group with the anti-hyperventilation instruction. Neither the feeling of air hunger nor task difficulty were affected by the instruction. There were no significant effects of the instruction on affective state. The present study indicates that a brief anti-hyperventilation instruction may be used to decrease drop in PetCO₂ and symptoms of hyperventilation during breathing at 0.1 Hz and that the instruction is well tolerated.

Exertional Dyspnea in Childhood: Is There an Iceberg Beneath the Apex?

This essay expounds on fundamental, quantitative elements of the exercise ventilation in children, which was the subject of the Tom Rowland Lecture given at the NASPEM 2018 Conference. Our knowledge about how much ventilation rises during aerobic exercise is reasonably solid; our understanding of its governance is a work in progress, but our grasp of dyspnea and ventilatory limitation in children (if it occurs) remains embryonic. This manuscript summarizes ventilatory mechanics during dynamic exercise, then proceeds to outline our current understanding of mechanisms of dyspnea, particularly during exercise (exertional dyspnea). Most research in this field has been done in adults, and the vast majority of these studies in patients with chronic obstructive pulmonary disease. To what extent conclusions drawn from this literature apply to children and adolescents-both healthy and those with cardiopulmonary disease-will be discussed. The few, recent, pertinent, pediatric studies will be reviewed in an attempt to provide an empirical basis for proposing a hypothetical model to study exertional dyspnea in youth. Just as somatic growth will have consequences for ventilatory and exercise capacity, so too will neural developmental plasticity and experience affect perception of dyspnea. Our path to understand how these evolving inputs and influences summate during a child's life will be Columbus' India.

Breathlessness amplifies amygdala responses during affective processing

Breathlessness is an aversive symptom in many prevalent somatic and psychiatric diseases and is usually experienced as highly threatening. It is strongly associated with negative affect, but the underlying neural processes remain poorly understood. Therefore, using fMRI, the present study examined the effects of breathlessness on the neural processing of affective visual stimuli within candidate brain areas including the amygdala, insula, and anterior cingulate cortex (ACC). During scanning, 42 healthy volunteers, mean (SD) age: 29.0 (6.0) years, 14 female, were presented with affective picture series of negative, neutral, and positive valence while experiencing either no breathlessness (baseline conditions) or resistive-load induced breathlessness (breathlessness conditions). Respiratory measures and self-reports suggested successful induction of breathlessness and affective experiences. Self-reports of breathlessness intensity and unpleasantness were significantly higher during breathlessness conditions, mean (SD): 45.0 (16.6) and 32.3 (19.8), as compared to baseline conditions, mean (SD): 1.9 (3.0) and 2.9 (5.5). Compared to baseline conditions, stronger amygdala activations were observed during breathlessness conditions for both negative and positive affective picture series relative to neutral picture series, while no such effects were observed in insula and ACC. The present findings demonstrate that breathlessness amplifies amygdala responses during affective processing, suggesting an important role of the amygdala for mediating the interactions between breathlessness and affective states.

Being Anxious, Thinking Positively: The Effect of Emotional Context on Respiratory Sensory Gating

Respiratory sensory gating function has been found decreased by induced negative emotion in healthy adults. The increased ratio of the respiratory-related evoked potential (RREP) N1 peak amplitude for the second occlusion (S2) vs. the first occlusion (S1), S2/S1, is indicative of such decreased respiratory sensory gating. In this study, we tested the hypothesis that a positive emotional context would enhance respiratory sensory gating function in healthy individuals. In addition, we tested the modulating role of individual anxiety levels. We compared respiratory sensory gating in 40 healthy individuals by the paired inspiratory occlusion paradigm in a positive and neutral emotional context induced by emotional picture viewing. The results showed that the group averaged RREP N1 peak amplitudes S2/S1 ratios were significantly smaller in the positive compared to neutral context (0.49 vs. 0.64; p < 0.01). Further, analysis showed that the ratio decrease was due to a reduced response to the S2 and an enhanced response to S1 in the positive emotional context (p < 0.05). The subgroup analyses showed that in the positive emotional context, both individuals with low-moderate anxiety levels and those with no anxiety demonstrated a significant decrease of their S2/S1 ratio, but only those with low-moderate anxiety levels showed reduced S2 amplitudes compared to the neutral context (p < 0.01). In conclusion, our results suggest that a positive emotional context is related to better brain inhibitory mechanisms by filtering out repetitive respiratory stimuli in healthy individuals, especially in the presence of low-moderate anxiety levels. Further, investigation on how positive emotional contexts might contribute to improved respiratory sensory gating ability in clinical populations is necessary.

What is chronic cough in children?

The cough reflex is modulated throughout growth and development. Cough—but not expiration reflex—appears to be absent at birth, but increases with maturation. Thus, acute cough is the most frequent respiratory symptom during the first few years of life. Later on, the pubertal development seems to play a significant role in changing of the cough threshold during childhood and adolescence resulting in sex-related differences in cough reflex sensitivity in adulthood. Asthma is the major cause of chronic cough in children. Prolonged acute cough is usually related to the long-lasting effects of a previous viral airway infection or to the particular entity called protracted bacterial bronchitis. Cough pointers and type may orient toward specific etiologies, such as barking cough in croup or tracheomalacia, paroxystic whooping cough in Pertussis. Cough is productive in protracted bacterial bronchitis, sinusitis or bronchiectasis. Cough is usually associated with wheeze or dyspnea on exertion in asthma; however, it may be the sole symptom in cough variant asthma. Thus, pediatric cough has particularities differentiating it from adult cough, so the approach and management should be developmentally specific.

Cerebral anatomical changes in female asthma patients with and without depression compared to healthy controls and patients with depression

BACKGROUND

Population-based studies have demonstrated that asthma patients with depression symptoms are more likely to have poor asthma control and worse asthma outcomes. However, the underlying mechanism of the relationship between asthma and depression is still unclear. The present study aimed to examine the cerebral anatomical changes in female asthma patients with and without depression.

METHODS

Using structural magnetic resonance imaging (MRI) and a voxel-based morphometry technique, the primary effects of and the interaction between asthma and depression were analyzed. The cerebral gray matter volume (GMV) was compared between the groups. Correlation analyses between the GMV value of the brain regions and the clinical parameters were completed.

RESULTS

The interaction effect of asthma and depression was found on the right superior temporal gyrus (STG) and the left middle temporal gyrus. Patients with both asthma and depression showed less GMV in the right STG, the bilateral precuneus, and the right superior frontal gyrus compared to patients with asthma only. The GMV of the right STG showed a decrement form among the asthma only group, healthy controls and asthma plus depression group. In patients with asthma and depression, the volume of the right STG was positively correlated with PD20 (r = 0.714, p = 0.047) and negatively correlated with the nocturnal awakening score in the Asthma Control Test (r = -0.061, p = 0.038).

CONCLUSION

Current findings provided convergent evidence to support the critical role of the right STG in the brain mechanism that mediates asthma and depression.

Sex differences in the neural processing of aversive interoceptive events: the benefit of relief

Do men and women process and experience unpleasant bodily states differently? We used fMRI to determine brain processing before, during and after an aversive respiratory stimulation. No sex difference emerged during anticipation or stimulation. However, after the offset of the stimulation, men but not women showed enhanced activation of brain regions that are important for interoception and reward processing. Moreover, this activation was highest in those males who rated the preceding stimulation as most unpleasant. These results indicate that men are particularly sensitive to reward associated with the termination of an aversive event, which may signal relief.

Perceived triggers of asthma: key to symptom perception and management

Adequate asthma management depends on an accurate identification of asthma triggers. A review of the literature on trigger perception in asthma shows that individuals vary in their perception of asthma triggers and that the correlation between self-reported asthma triggers and allergy tests is only modest. In this article, we provide an overview of psychological mechanisms involved in the process of asthma triggers identification. We identify sources of errors in trigger identification and targets for behavioural interventions that aim to improve the accuracy of asthma trigger identification and thereby enhance asthma control.

Emotions and neural processing of respiratory sensations investigated with respiratory-related evoked potentials

OBJECTIVE

Patients with respiratory diseases such as asthma and chronic obstructive pulmonary disease frequently experience respiratory sensations, which are often perceived as unpleasant or threatening. However, the accurate perception of respiratory sensations is important for the management and treatment of these diseases. Emotions can substantially influence the perception of respiratory sensations and might affect the course of respiratory diseases, but the underlying neural mechanisms are poorly understood. The respiratory-related evoked potential (RREP) recorded from the electroencephalogram is a noninvasive technique that allowed first studies to examine the impact of emotions on the neural processing of respiratory sensations.

METHODS

In this review, we will briefly introduce the importance of the perception of respiratory sensations and the influence of emotions on respiratory perception. We then provide an overview on the technique of RREP and present a systematic review on recent findings using this technique in the context of emotions.

RESULTS AND CONCLUSIONS

The evidence currently available from studies in healthy individuals suggests that short-lasting emotional states and anxiety affect the later RREP components (N1, P2, P3) related to higher-order neural processing of respiratory sensations, but not the earlier RREP components (Nf, P1) related to first-order sensory processing. We conclude with a discussion of the implications of this work for future research that needs to focus on respiratory patient groups and the associated clinical outcomes.

Psychosocial factors and behavioral medicine interventions in asthma

OBJECTIVE

This review examines the evidence for psychosocial influences in asthma and behavioral medicine approaches to its treatment.

METHOD

We conducted a systematic review of the literature on psychosocial influences and the evidence for behavioral interventions in asthma with a focus on research in the past 10 years and clinical trials. Additional attention was directed at promising new developments in the field.

RESULTS

Psychosocial factors can influence the pathogenesis and pathophysiology of asthma, either directly through autonomic, endocrine, immunological, and central nervous system mechanisms or indirectly through lifestyle factors, health behaviors, illness cognitions, and disease management, including medication adherence and trigger avoidance. The recent decade has witnessed surging interest in behavioral interventions that target the various pathways of influence. Among these, self-management training, breathing training, and exercise or physical activation programs have proved particularly useful, whereas other essential or promising interventions, such as smoking cessation, dietary programs, perception and biofeedback training, and suggestive or expressive psychotherapy, require further, more rigorous evaluation. Given the high comorbidity with anxiety and mood disorders, further evaluation of illness-specific cognitive behavior therapy is of particular importance. Progress has also been made in devising community-based and culturally tailored intervention programs.

CONCLUSION

In concert with an essential medication treatment, behavioral medicine treatment of asthma is moving closer toward an integrated biopsychosocial approach to disease management.

Neuromodulation and Palliative Medicine

The palliative care population is generally vulnerable to experiencing medication-induced adverse effects and drug–drug interactions. Neuromodulation may offer particular advantages over systemic medications in this population. Spinal cord stimulation and peripheral nerve stimulation have long been utilized in efforts to provide analgesia for various painful conditions. More recently, deep brain stimulation/motor cortex stimulation has anecdotally been utilized for certain intractable pain states. Although brain electrical stimulation has not been adequately trialed or in some cases even tried at all for management of a variety of symptoms, it is conceivable that in the future it may be a potential therapeutic option in efforts to palliate various severe refractory symptoms (eg, intractable pain, nausea, dyspnea, delirium).

The impact of emotion on the perception of graded magnitudes of respiratory resistive loads

Emotional state can modulate the perception of respiratory loads but the range of respiratory load magnitudes affected by emotional state is unknown. We hypothesized that viewing pleasant, neutral and unpleasant affective pictures would modulate the perception of respiratory loads of different load magnitudes. Twenty-four healthy adults participated in the study. Five inspiratory resistive loads of increasing magnitude (5, 10, 15, 20, 45 cm H(2)O/L/s) were repeatedly presented for one inspiration while participants viewed pleasant, neutral and unpleasant affective picture series. Participants rated how difficult it was to breathe against the load immediately after each presentation. Only at the lowest load, magnitude estimation ratings were greater when subjects viewed the unpleasant series compared to the neutral and pleasant series. These results suggest that negative emotional state increases the sense of respiratory effort for single presentations of a low magnitude resistive load but high magnitude loads are not further modulated by emotional state.

The impact of emotions on symptom perception in patients with asthma and healthy controls

Accurate perception of respiratory symptoms is highly important for course and treatment of asthma. Recent findings suggest that emotions can greatly impact respiratory symptom perception. This study compared the impact of emotions on respiratory symptom perception between patients with asthma and matched healthy controls. Pleasant and unpleasant emotional states were elicited by viewing emotional picture series while symptom reports and respiratory parameters were measured. Greater symptom report was observed for the unpleasant compared to the pleasant emotional state that was not related to respiratory parameters. Notably, this effect was comparable between patients with asthma and healthy controls. The present results suggest that the impact of emotions on respiratory symptom perception is a rather general phenomenon and not dependent upon previous experiences with asthma symptoms.

Structural brain changes related to disease duration in patients with asthma

Dyspnea is the impairing, cardinal symptom patients with asthma repeatedly experience over the course of the disease. However, its accurate perception is also crucial for timely initiation of treatment. Reduced perception of dyspnea is associated with negative treatment outcome, but the underlying brain mechanisms of perceived dyspnea in patients with asthma remain poorly understood. We examined whether increasing disease duration in fourteen patients with mild-to-moderate asthma is related to structural brain changes in the insular cortex and brainstem periaqueductal grey (PAG). In addition, the association between structural brain changes and perceived dyspnea were studied. By using magnetic resonance imaging in combination with voxel-based morphometry, gray matter volumes of the insular cortex and the PAG were analysed and correlated with asthma duration and perceived affective unpleasantness of resistive load induced dyspnea. Whereas no associations were observed for the insular cortex, longer duration of asthma was associated with increased gray matter volume in the PAG. Moreover, increased PAG gray matter volume was related to reduced ratings of dyspnea unpleasantness. Our results demonstrate that increasing disease duration is associated with increased gray matter volume in the brainstem PAG in patients with mild-to-moderate asthma. This structural brain change might contribute to the reduced perception of dyspnea in some patients with asthma and negatively impact the treatment outcome.

Dyspnoea and the brain

Chronic dyspnoea is a devastating symptom that debilitates millions of people worldwide. It causes a large burden on both patient and carer, and significant costs to society and health services. Treatment options are limited. Much effort has been directed at optimising lung function and improving exercise capacity, however, the brain mechanisms underlying dyspnoea perception have received less attention. In this review, we focus on cognitive and affective aspects of dyspnoea and discuss how novel neuroimaging methods can provide quantitative measures of these subjective sensations. We draw parallels with the more advanced field of chronic pain, and explain some of the challenges faced when imaging dyspnoea. To date, brain mechanisms of dyspnoea have been investigated in a handful of studies by a limited number of authors. These have found consistent activation in the insular cortex, the anterior cingulate cortex and the amygdala. Novel neuroimaging methods and an improved understanding of perceptual mechanisms underlying dyspnoea now position us to transform dyspnoea research. Future research should investigate how brain regions associated with dyspnoea interact, as well as accurately correlate this neuronal activation with reliable behavioural measures. A better understanding of the brain processes underlying dyspnoea perception will lead to new therapies that will improve quality of life for a very large group of patients.

Dyspnea-related anxiety: The Dutch version of the Breathlessness Beliefs Questionnaire

Dyspnea-related anxiety may lead to reduced quality of life and functional disability through fearful avoidance of dyspnea-evoking activity. We describe the validation of a generic - diagnosis-independent - instrument assessing dyspnea-related anxiety. A total of 187 patients with respiratory diseases completed the Breathlessness Beliefs Questionnaire (BBQ), a 17-item questionnaire adapted from the Tampa Scale for Kinesiophobia (TSK), a measure of how harmful pain patients think painful movement is and to what extent they think activity should be avoided. Measures of negative and positive affectivity (PANAS), anxiety and depression (HADS), functional status (PFSDQ), and health-related quality of life (CRDQ) were also completed. Principal component analysis and item-total correlations suggested a reliable (reduced) 11-item BBQ (Cronbach's alpha = .85) with two factors converging with the TSK factors: a 'somatic focus' factor assessing the harmfulness of dyspnea and the underlying pathology and an 'activity avoidance' factor assessing beliefs that activity should be avoided. Correlational analyses support the construct validity of the BBQ: higher scores on the BBQ are associated with reduced health-related quality of life and functional status. Associations between 'somatic focus' and negative affectivity and anxiety and between 'activity avoidance' and positive affectivity and depression further supported the validity of the BBQ and its subscales. The BBQ is a valid, short, and useful instrument to assess respiratory patients' beliefs about the harmfulness of their disease and physical activities. Further research is needed to document to what extent BBQ scores are related to daily life activities and symptoms.

The impact of emotion on respiratory-related evoked potentials

Emotion influences the perception of respiratory sensations, although the specific mechanism underlying this modulation is not yet clear. We examined the impact of viewing pleasant, neutral, and unpleasant affective pictures on the respiratory-related evoked potential (RREP) elicited by a short inspiratory occlusion in healthy volunteers. Reduced P3 amplitude of the RREP was found for respiratory probes presented when viewing pleasant or unpleasant series, when compared to those presented during the neutral series. Earlier RREP components, such as Nf, P1, N1, and P2, showed no modulation by emotion. The results suggest that emotion impacts the perception of respiratory sensations by reducing the attentional resources available for processing afferent respiratory sensory signals.

Do asthma patients prefer to monitor symptoms or peak flow?

We administered a 65-item survey to patients to assess preference of symptoms and peak flow to detect worsening asthma and to collect information about asthma triggers, asthma knowledge sources, and barriers to peak flow meter use. It was completed by 139 asthma patients. Survey responses were comparable for adult and pediatric patients and for those who owned peak flow meters and those who did not. But patients who owned a peak flow meter reported more severe asthma than others. On average, the patients preferred symptoms to peak flow for assessing worsening asthma. It is likely that the preference for symptom over peak flow monitoring was effort related: Patients preferred symptom monitoring because it was the easier of the two to conduct.

The impact of affective states on the perception of dyspnea in patients with chronic obstructive pulmonary disease

Dyspnea is the cardinal symptom of chronic obstructive pulmonary disease (COPD). Affective states can profoundly impact upon the perception of dyspnea, but little is known about this relationship in patients with COPD. We, therefore, examined the impact of viewing positive versus negative affective picture series on perceived dyspnea during two cycle ergometer exercise tests (CEET) in 30 patients with COPD. Whereas cardiopulmonary measures indicated comparable exercise intensity during both CEETs, parallel viewing of negative affective pictures resulted in increased dyspnea ratings compared to positive affective pictures. Regression analyses showed that only during positive picture viewing increases in the affective unpleasantness of dyspnea, but not in the sensory intensity of dyspnea, during CEETs were predictive of greater dyspnea during everyday activities and reduced health-related quality of life. The results suggest that negative affective states increase perceived dyspnea in patients with COPD and underline the importance of targeting the affect-dyspnea-relationship in this patient group.

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.

A hidden cost of happiness in children

Happiness is generally considered an emotion with only beneficial effects, particularly in childhood. However, there are some situations where the style of information processing triggered by happiness could be a liability. In particular, happiness seems to motivate a top-down processing style, which could impair performance when attention to detail is required. Indeed, in Experiment 1, 10- to 11-year-old children (N = 30) induced to feel a happy mood were slower to locate a simple shape embedded in a complex figure than those induced to feel a sad mood. In Experiment 2, 6- to 7-year-old children (N = 61) induced to feel a happy mood found fewer embedded shapes than those induced to feel a sad or neutral mood. Happiness may have unintended and possibly undesirable cognitive consequences, even in childhood.

Inaccurate perception of asthma symptoms: a cognitive-affective framework and implications for asthma treatment

Inaccurate perception of respiratory symptoms is often found in asthma patients. Typically, patients who inaccurately perceive asthma symptoms are divided into underperceivers and overperceivers. In this paper we point out that this division is problematic. We argue that little evidence exists for a trait-like stability of under- and overperception and that accuracy of respiratory symptom perception is highly variable within persons and strongly influenced by contextual information. Particularly, expectancy and affective cues appear to have a powerful influence on symptom accuracy. Based on these findings and incorporating recent work on associative learning, attention and mental representations in anxiety and symptom perception, we propose a cognitive-affective model of symptom perception in asthma. The model can act as a framework to understand both normal perception as well as under- and overperception of asthma symptoms and can guide the development of affect-related interventions to improve perceptual accuracy, asthma control and quality of life in asthma patients.

Dyspnoea in children. Does development alter the perception of breathlessness?

Dyspnoea, the perception of an unpleasant and/or uncomfortable sensation of breathlessness, offers several physiological, anatomical and teleological analogies with pain. Pain perception has been shown to exist in the newborn, suggesting that dyspnoea may also occur from birth onwards. The perception of breathlessness will be subservient to developmental changes in the behaviour of sensors and lung and muscular receptors implicated in dyspnoea, some of which are known to be active at time of birth. For example, perinatal resetting of the arterial chemoreceptor could lead to transient depression of the dyspnoeic response to hypoxia. However, though early evoked ventilatory responses and peripheral receptor maturation do exist, dyspnoea will only occur if the corresponding central neural circuitry undergoes parallel maturation. Our knowledge of dyspnoea in later childhood is based on a small number of clinical or psychophysical studies, predominantly dealing with asthma and exercise. There is a thus a clear need for systematic assessment of the existence and severity of dyspnoea sensing in younger children that takes into account its role as an alarm mechanism for triggering adaptive and/or protective responses.

The urge-to-cough and cough motor response modulation by the central effects of nicotine

The urge-to-cough is a respiratory sensation that precedes the cough motor response. Since affective state modulates the perception of respiratory sensations such as dyspnoea, we wanted to test whether nicotine, an anxiolytic, would modulate the urge-to-cough and hence, the cough motor response. We hypothesized that withdrawal from and administration of nicotine in smoking subjects would modulate their anxiety levels, urge-to-cough and cough motor response to capsaicin stimulation. Twenty smoking (SM) adults (8F, 12M; 22+/-3 years; 2.9+/-2.0 pack years) and matched non-smoking (NS) controls (22+/-2 years) were presented with randomized concentrations of capsaicin (0-200 microM) before and after nicotine (SM only) gum and/or placebo (SM and NS) gum. Subjects rated their urge-to-cough using a Borg scale at the end of each capsaicin presentation. Cough number and cough motor pattern were determined from airflow tracings. Subjects completed State-Trait Anxiety Inventory (STAI) questionnaires before and after gum administration. SM subjects that withdrew from cigarette smoking for 12 h exhibited an increase in anxiety scores, a greater number of coughs and higher urge-to-cough ratings compared to NS subjects. Administration of nicotine gum reduced anxiety scores, cough number and urge-to-cough ratings to match the NS subjects. There was no effect of placebo gum on any of the measured parameters in the SM and NS groups. The results from this study suggest that modulation of the central neural state with nicotine withdrawal and administration in young smoking adults is associated with a change in anxiety levels which in turn modulates the perceptual and motor response to irritant cough stimulants.

Exploring and explaining low participation in physical activity among children and young people with asthma: a review

Background

Asthma is the most common chronic illness among children and accounts for 1 in 5 of all child GP consultations. This paper reviews and discusses recent literature outlining the growing problem of physical inactivity among young people with asthma and explores the psychosocial dimensions that may explain inactivity levels and potentially relevant interventions and strategies, and the principles that should underpin them.

Methods

A narrative review based on an extensive and documented search of search of CinAHL, Embase, Medline, PsycINFO and the Cochrane Library.

Results & Discussion

Children and young people with asthma are generally less active than their non-asthmatic peers. Reduced participation may be influenced by organisational policies, family illness beliefs and behaviours, health care advice, and inaccurate symptom perception and attribution. Schools can be reluctant to encourage children to take part in physical education or normal play activity due to misunderstanding and a lack of clear corporate guidance. Families may accept a child's low level of activity if it is perceived that breathlessness or the need to take extra inhalers is harmful. Many young people themselves appear to accept sub-optimal control of symptoms and frequently misinterpret healthy shortness of breath on exercising with the symptoms of an impending asthma attack.

Conclusion

A multi-faceted approach is needed to translate the rhetoric of increasing activity levels in young people to the reality of improved fitness. Physical activity leading to improved fitness should become part of a goal orientated management strategy by schools, families, health care professionals and individuals. Exercise induced asthma should be regarded as a marker of poor control and a need to increase fitness rather as an excuse for inactivity. Individuals' perceptual accuracy deserves further research attention.

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.