Neuropsychological dysfunction in asthmatic children

Asthma, the central nervous system, and neurocognition: Current findings, potential mechanisms, and treatment implications

Accumulating behavioral evidence suggests that asthma is associated with cognitive deficits. A number of studies have identified potential biological contributions to cognition in asthma; however, mechanistic pathways of central nervous system (CNS) involvement in asthma are yet to be established. We therefore conducted a literature review to identify studies examining potential CNS contributions to cognition in asthma. In this review, we discuss our general understanding of the CNS in asthma in the context of cognitive performance and outline a working model of mechanistic pathways linking the proposed neural influences of asthma pathology with cognition. To this extent, we incorporate neural, behavioral, psychological, social and environmental factors. Finally, we underscore the clinical significance of the CNS and neurocognitive sequelae in asthma, highlighting potential opportunities for routine monitoring, therapeutic intervention, and recommend key areas for future research.

Poor Executive Functions among Children with Moderate-into-Severe Asthma: Evidence from WCST Performance

Executive functions (EFs) measures of 27 asthmatic children, with general learning difficulties, were tested by using the Wisconsin card sorting test (WCST), and were compared to the performances of 30 non-asthmatic children with general learning difficulties. The results revealed that the asthmatic group has poor performance through all the WCST psychometric parameters and especially the perseverative errors one. The results were discussed in light of the postulation that poor EFs could be associated with the learning difficulties of asthmatic children. Neurophysiological framework has been suggested to explain the etiology of poor EFs among children with moderate into severe asthma.

Lung disease as a determinant of cognitive decline and dementia

Almost 40 million people currently live with dementia but this is estimated to double over the next 20 years; despite this, research identifying modifiable risk factors is scarce. There is increasing evidence that cognitive impairment is more frequent in those with chronic lung disease than those without. Chronic obstructive pulmonary disease affects 210 million people, with cognitive impairment present in 60% of certain populations. Co-morbid cognitive dysfunction also appears to impact on important outcomes such as quality of life, hospitalisation and survival. This review summarises the evidence of an association between cognition, impaired lung function and obstructive lung disease. It goes on to examine the contribution of neuro-imaging to our understanding of the underlying pathophysiology. While the mechanisms of brain pathology and cognitive impairment are likely to be complex and multi-factorial, there is evidence to suggest a key role for occult cerebrovascular damage independent of traditional vascular risk factors, including smoking.

Psychological interventions for children with asthma

BACKGROUND

Asthma is a chronic disease of inflammation and smooth muscle dysfunction, including bronchoconstriction. These symptoms are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. Psychological factors may influence the symptoms and management of asthma in children in many ways, for example, evidence suggests that emotional stress can either precipitate or exacerbate both acute and chronic asthma.

OBJECTIVES

To assess the efficacy of psychological interventions in improving health and behavioural outcomes for children with asthma.

SEARCH STRATEGY

The Cochrane Airways Group Specialised Register and PsycINFO were searched with pre-defined terms up until March 2005.

SELECTION CRITERIA

Randomised controlled trials published in any language assessing the effects of a psychological intervention compared with a control intervention in children and adolescents with asthma were included in the review. Cross-over trials were considered inappropriate for studies using psychological interventions and were therefore excluded from this systematic review.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed the relevance of abstracts identified by electronic searching and retrieved agreed studies for further scrutiny. The studies that met the inclusion criteria were assembled and data extracted.

MAIN RESULTS

Twelve studies (588 children) were included in the review. Study quality was poor and sample sizes were frequently small. A meta-analysis was possible on two studies only examining the effects of relaxation therapy on PEFR which favoured the treatment group (32 L/min, 95% CI 13 to 50 L/min). No other meta-analysis could be performed due to the diversity of interventions and the outcomes assessed. In addition, many studies reported insufficient data.

AUTHORS' CONCLUSIONS

This review was unable to draw firm conclusions for the role of psychological interventions for children with asthma. This review demonstrates the absence of an adequate evidence base and highlights the need for well-conducted and reported randomised trials in this area.

Sleep problems in children with common medical disorders

Sleep problems are common in many pediatric medical disorders and complicate management and patient outcomes. A wide range of conditions, including asthma, cystic fibrosis, sickle cell disease, gastroesophageal reflux, neuromuscular diseases, scoliosis, craniofacial abnormalities, obesity, and chromosomal disorders, have various sleep disturbances, including sleep-disordered breathing, ventilatory dysfunction, sleep-onset and sleep maintenance problems, and circadian rhythm disturbances. Given the adverse neurocognitive and physiologic outcomes associated with a deranged night's sleep, it is important for pediatricians to be able to anticipate, recognize, and appropriately manage these problems. This article reviews the known sleep-related problems of a few relatively common pediatric disorders.

Psychopathology in patients with severe asthma is associated with increased health care utilization

Severe asthma accounts for the majority of health costs for this disease, which is mainly related to the treatment of failed control. Several psychosocial factors have been associated with poor asthma control, but the question remains whether psychiatric disorder in patients with severe asthma predisposes for increased health care utilization. In the present study we compared outpatients with severe asthma with and without psychological dysfunctioning with respect to health care utilization. All patients used high dose inhaled corticosteroids and long-acting bronchodilators for more than 1 yr, and had difficult-to-control asthma, requiring one or more courses of corticosteroids during the past year or maintenance therapy with prednisone. Medical history was taken and health care utilization questionnaires were completed. The General Health Questionnaire (GHQ) was used to identify psychiatric cases (GHQ-12 score of > or = 6). There were no differences between the psychiatric cases (n = 21) and the noncases (n = 77) with respect to demographic and objective disease characteristics. However, the psychiatric cases had increased odds ratios (OR) for frequent visits to GP (OR = 5.9), frequent emergency visits (OR = 5.3), frequent exacerbations (OR = 12.4), and frequent hospitalizations (OR = 4.8) as compared with the nonpsychiatric patients. The present findings suggest that the morbidity and costs of asthma might be related to the level of psychological dysfunctioning in patients with severe asthma rather than to asthma severity per se, thereby identifying an area of potential intervention.

Factors associated with self-concept in children with asthma

PURPOSE

To investigate the relationship of demographic asthma, family, and child factors with self-concept in children with asthma.

METHODS

Data were collected twice approximately 4 years apart from both the affected children and their mothers (N = 134) via interviews and self-report questionnaire.

FINDINGS

Children who demonstrated more negative attitudes toward their illness, had less satisfaction with family relationships, and used more negative coping behaviors had the poorest self-concepts. Over time, the greatest improvement in self-concept occurred in children whose attitudes and satisfaction with family relationships improved and whose use of negative coping behaviors decreased.

CONCLUSIONS

Results suggest that some children with asthma, especially girls with severe asthma, appear to be at risk for poor self-concept.

Neurocognitive functioning in children with mild and moderate asthma in the childhood asthma management program. The Childhood Asthma Management Program (CAMP) Research Group

BACKGROUND

The Childhood Asthma Management Program (CAMP) is a multicenter double-blind, randomized, placebo-controlled, clinical trial of two anti-inflammatory agents and placebo in children with mild and moderate asthma.

OBJECTIVE

The interrelationship between asthma severity and neurocognitive functioning among 1041 children (age range, 5-12 years) enrolled in the CAMP trial was examined.

METHODS

Asthma severity was established at baseline with a clinical history of asthma symptomatology and measures of lung function (spirometry and methacholine challenge). Diary cards were used in a screening to record nighttime awakenings and doctor contacts caused by asthma symptoms, symptom severity, and number of puffs from a rescue inhaler. All children received a comprehensive neurocognitive assessment at the end of the 28-day screening period (before randomization), including measures of intelligence, attention, memory, and academic achievement.

RESULTS

Significant differences were found between children with mild and moderate asthma on lung function and symptom outcome variables (log(e)FEV(1)PC(20), DeltaFEV(1) percent predicted, change in peak flow percent predicted, nighttime awakenings caused by asthma, average symptom severity score, and average daily number of puffs from a rescue inhaler) but not on neurocognitive variables. Multiple regression analyses revealed that asthma outcomes could not be predicted by neurocognitive variables despite controlling for socioeconomic status. The prevalence of neurocognitive dysfunction, as indicated by the use of psychostimulant medication, was found to be consistent with that found in the existing literature.

CONCLUSION

Mild and moderate asthma symptoms are not related to neurocognitive functioning in the children enrolled in CAMP. Mean performance on neurocognitive variables was found to be similar to that of national normative data.

Caffeine for asthma

BACKGROUND

Caffeine has a variety of pharmacological effects. It is chemically related to the drug theophylline which is used to treat asthma. Accordingly, interest has been expressed in its potential role as an asthma treatment. A number of studies have explored the effects of caffeine in asthma, this is the first review to systematically examine and summarise the evidence.

OBJECTIVES

Caffeine is a weak bronchodilator and it also reduces respiratory muscle fatigue. It has been suggested that caffeine may reduce asthma symptoms. The objective of this review was to assess the effects of caffeine on lung function and identify whether there is a need to control for caffeine consumption prior to lung function testing.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and the reference lists of articles. We also contacted study authors.

SELECTION CRITERIA

Randomised trials of oral caffeine compared to placebo in adults with asthma.

DATA COLLECTION AND ANALYSIS

Trial quality assessment and data extraction were done independently by two reviewers.

MAIN RESULTS

Six trials involving a total of 55 people were included. The studies were all of cross-over design and of high quality. In comparison with placebo, caffeine appears to improve lung function for up to two hours after consumption. Forced expiratory volume in one minute showed a small improvement up to two hours after caffeine use (standardised mean difference -0.73, 95% confidence interval -1.20 to -0.25). Mid-expiratory flow rates also showed a small improvement with caffeine and this was sustained up to four hours.

REVIEWER'S CONCLUSIONS

Caffeine appears to improve airways function modestly in people with asthma for up to four hours. People may need to avoid caffeine for at least four hours prior to lung function testing.