Sleep disturbances in children with multiple disabilities

Summary

Introduction

Although sleep disturbances in disabled children are of central clinical importance, there is little research on that topic. There are no data available on frequency, severity or aetiology of sleep disturbances and related symptoms in this specific patient group.

Objective

To review the current state of research and outline future research objectives.

Methods

We searched international scientific databases for relevant publications from 1980-2009. From all papers qualifying for further analysis we retrieved systematic information on sample characteristics, sleep assessment tools and their test quality criteria, and core findings.

Results

61 publications including 4392 patients were categorized as “mixed” (reporting on heterogeneous diagnoses), or “specified” papers (specific diagnoses) based on international classification of diseases (ICD) 10 classification. To assess sleep disturbances, most authors relied on subjective instruments with poor psychometric quality. Mean prevalence of sleep disturbances was 67% (76%,“mixed” group; 65%, “specified” group). In children suffering severe global cerebral injury, the prevalence of sleep disturbances was even higher (>90%). The most frequent symptoms were insomnia and sleep-related respiratory disorders. Some of these symptoms were closely associated with specific medical syndromes.

Conclusion

There is an urgent need for sleep disturbance assessment tools evaluated for the patient group of interest. By use of validated assessment tools, patient factors, which may be crucial in causing sleep disturbances, may be investigated and appropriate treatment strategies may be developed.

Introduction

Glossary

Disability, is the functional inability of an individual to perform any activity in the manner or within the range considered “normal” for any human being. It is a restriction of activity or ability as a result of impairment and interferes in the performance of daily activities by an individual.

Multiple disabilities, is the co-existence of two or more disabilities such as intellectual impairment and physical handicap.

“Specified” group: sample with specific disease

“Mixed” group: sample with heterogeneous diseases

Since the 1980s, sleep disturbance in healthy children has been a significant issue in paediatrics.1, 2 With a prevalence of 25–40%, sleep disturbance is frequent*3, 4, 5, *6 and has numerous negative effects on physical symptoms, cognitive development, and daytime behaviour.4, *7, *8, 9

Clinical practice as well as research data show that sleep disturbance is not only a problem in healthy children requiring treatment, but is particularly significant in children with physical and mental disability.¹⁰ The more pronounced the disabilities in these patients (co-existence of impairments), the more frequent and severe are the sleep disturbances and the less likely is a spontaneous symptom relieve.*6, *11 Clinical studies and data on frequency, type and symptoms (e.g., daytime restlessness) of sleep disturbance are lacking in this patient group.*6, *10, *11, *12, *13 Furthermore, there is controversial discussion about the aetiological factors, which are responsible for the high prevalence of sleep disturbance in children with multiple disabilities. Some authors assumed factors depending on the specific diagnosis (e.g., brain abnormality)*14, 15, 16, 17 or specific factors inherent to the main diagnosis (e.g., spasticity).18, 19, 20 Since diagnosis of the underlying pathophysiology is not possible in about 50% of children suffering from severe motor or psychomotor life-limiting disease,²¹ the feasibility of exploring the impact of the underlying disease as an aetiological factor for sleep disturbance may be disputed. However, information on prevalence, type and severity of sleep disturbance with respect to the main diagnosis is helpful for clinical practice.

In addition, there are other factors secondary to the disease (e.g., pain), adverse effects of medication, psychosocial factors (e.g., parental distress and behaviour) or environmental factors (e.g., sleep environment, parent–child interaction) which negatively impact on the quality of sleep.*3, 17, 22 The diminished sleep quality may further lead to increased daytime drowsiness, restlessness, and aggravation of the underlying disease (i.e., lower seizure threshold in epileptic disorders, increased level of distress, or impaired regenerative processes). These processes creating a vicious cycle with ever increasing sleep disturbance.

One reason for the lack of sleep research in children with multiple disabilities may be the difficulty in selecting a suitable, validated instrument capable of reliably assessing sleep disturbance in this patient group. Most sleep assessment tools have been designed for use in healthy children.23, 24, 25 However, their use in children with multiple disabilities is questionable given the clinical features and the complexity of disabilities and symptoms of these children, which did not allow their parents to evaluate some sleep disorders (e.g., sleep talking, somnambulism, nightmare). Additionally, questionnaires that have been designed for use in healthy children do not consider factors that disrupt sleep which are inherent to the main diagnosis (e.g., waking for treatment, spasm, etc.) in children with multiple disabilities.24, 26

The aim of this paper is to review the literature on prevalence, symptoms and assessment of sleep disturbance in children with multiple disabilities.

The following questions were addressed by a comprehensive literature review:

• How frequent and what type of sleep disturbance occurs in this specific group of patients with respect to the underlying pathology of diseases? We depicted frequency and type of sleep disturbance in samples with heterogeneous diagnoses (mixed group) and in samples with specific diagnosis (specified group).

• Which assessment tools have been implemented and what is their psychometric quality?