Kurt Lushington

Behavior and Neurocognitive Performance in Children Aged 5-10 Years Who Snore Compared to Controls

Sleep disordered breathing in children is a common but largely underdiagnosed problem. It ranges in severity from primary snoring to obstructive sleep apnea syndrome (OSAS). Preliminary evidence suggests that children with severe OSAS show reduced neurocognitive performance, however, less is known about children who snore but do not have severe upper airway obstruction. Participants included 16 children referred to the Ear, Nose and Throat/Respiratory departments of a Children’s Hospital for evaluation of snoring and 16 non-snoring controls aged 5-10 years. Overnight polysomnography (PSG) was carried out in 13 children who snored and 13 controls. The PSG confirmed the presence of primary snoring in seven and very mild OSAS (as evidenced by chest wall paradox) in eight children referred for snoring while controls showed a normal sleep pattern. To test for group differences in neurocognitive functioning and behavior, children underwent one day of testing during which measures of intelligence, memory, attention, social competency, and problematic behavior were collected. Compared to controls, children who snored showed significantly impaired attention and, although within the normal range, lower memory and intelligence scores. No significant group differences were observed for social competency and problematic behavior. These findings suggest that neurocognitive performance is reduced in children who snore but are otherwise healthy and who do not have severe OSAS. They further imply that the impact of mild sleep disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and developmental progress.

Are sleep problems under-recognised in general practice?

Aims: To evaluate the frequency of sleep problems in Australian children aged 4.5–16.5 years, and to determine whether the frequency of sleep problems on questionnaire predicts the reporting of sleep problems at consultation. Methods: Parents of 361 children (aged 4.5–16.5 years) attending their general practitioner for “sick” visits were asked to assess their child’s sleep over the previous six months using the Sleep Disturbance Scale for Children, from which six sleep “disorder” factors and a total sleep problem score were obtained. Results: The percentage of children with a total sleep problem score indicative of clinical significance (T score >70 or >95th centile) was 24.6% (89/361). Despite this high frequency, parents only addressed sleep problems in 4.1% (13/317) of cases and reported that GPs discussed sleep problems in 7.9% (25/317) of cases. Of the 79 children who reported total sleep problem T scores in the clinical range, only 13.9% (11/79) discussed sleep with their general practitioner within the previous 12 months. Regression analyses revealed an age related decrease in problems with sleep-wake transition and sleep related obstructive breathing; sleep hyperhydrosis, initiating and maintaining sleep, and excessive daytime sleepiness did not significantly decrease with age. No significant gender differences were observed. Conclusions: Results suggest that chronic sleep problems in Australian children are significantly under-reported by parents during general practice consultations despite a relatively high frequency across all age groups. Given the impact on children and families, there is a need for increased awareness of children’s sleep problems in the community and for these to be more actively addressed at consultation.

Development and validation of a scale to measure work-related fatigue and recovery : The Occupational Fatigue Exhaustion/Recovery scale (OFER)

Objective: Various empirical studies link persistent failure to recover from acute fatigue to the evolution of chronic fatigue. However, existing fatigue measurement scales do not tend to distinguish between acute and chronic fatigue elements well, and none include a measure of effective recovery from fatigue. Methods: The 15 item Occupational Fatigue Exhaustion Recovery (OFER) scale has been developed and validated in three study populations specifically to measure work-related fatigue. Results: The OFER scale possesses robust, gender-bias free psychometric characteristics. Its three subscales identify and distinguish between chronic work-related fatigue traits, acute end-of-shift states and effective fatigue recovery between shifts. Conclusion: These studies confirm the mediating role of intershift-shift recovery in the evolution of adaptive end-of-shift fatigue states to maladaptive persistent fatigue traits. The OFER scale is suggested as a potentially valuable new tool for use in work-related fatigue research.

Urinary 6-sulfatoxymelatonin excretion and aging: New results and a critical review of the literature

Abstract: The apparent age‐related decline in melatonin production has been thought to continue in a secular manner across the lifespan. While it is clear that melatonin levels in children and adolescents are elevated compared to older individuals, the question of whether there is a sudden or gradual change has not been adequately addressed. In this study, we report the excretion of the melatonin metabolite, 6‐sulfatoxymelatonin in 253 subjects aged between 21 and 82 yr. The correlation with age was significant (r= ‐ 0.24; P < 0.05). When the data was analysed by ANOVA using 5‐yr age spans, there was a significant effect of age, but post hoc analysis indicated that after 25 yr of age there was no significant decline in excretion of the metabolite. Thus, although the oldest subjects excreted 36% less melatonin metabolite than the youngest, the decrease occurred at a very early age. In the second part of the study, we re‐evaluated the data from seven previous studies that measured plasma melatonin levels or metabolite excretion across a wide range of ages and 11 studies comparing young versus older subjects. Statistical analysis by ANOVA again suggested that the changes in melatonin occurring with age were essentially complete before 30 yr of age. The youngest subjects produced at the most twice the amount of melatonin as the oldest subjects. Finally, we evaluated the mean plasma melatonin levels in 144 groups of normal subjects reported in 137 separate publications with respect to age. Again, whereas there was a significant correlation with age, ANOVA showed that there was no difference between groups after 35 yr of age, and the oldest groups had levels that were only 43% of the youngest groups. We conclude that melatonin production is lower in older people, but that the change occurs very early in life, around 20–30 yr of age.

Adenotonsillectomy and neurocognitive deficits in children with Sleep Disordered Breathing.

Background Sleep Disordered Breathing (SDB) is a common childhood disorder that encompasses a range of sleep-related upper airway obstruction. Children with SDB demonstrate significant neurocognitive deficits. Adenotonsillectomy is the first line of treatment for SDB and whilst this improves respiratory disturbance, it remains to be established whether neurocognitive gains also result. Methods A total of 44 healthy snoring children aged 3–12 years awaiting adenotonsillectomy (SDB group), and 48 age and gender matched non-snoring controls from the general community, completed the study. All children underwent polysomnography and neurocognitive assessment at baseline and after a 6-month follow-up (after surgery in the snoring group). Our primary aim was to determine whether neurocognitive deficits in snoring children were significantly improved following adenotonsillectomy. Results Wide ranging neurocognitive deficits were found at baseline in SDB children compared to controls, most notably a 10 point IQ difference (P<.001) and similar deficits in language and executive function. Whilst adenotonsillectomy improved respiratory parameters and snoring frequency at 6 months post surgery, neurocognitive performance did not improve relative to controls. Conclusion Adenotonsillectomy successfully treated the respiratory effects of SDB in children. However, neurocognitive deficits did not improve 6-months post-operatively.

Eczema and sleep and its relationship to daytime functioning in children

Chronic childhood eczema has significant morbidity characterised by physical discomfort, emotional distress, reduced child and family quality-of-life and, of particular note, disturbed sleep characterised by frequent and prolonged arousals. Sleep disturbance affects up to 60% of children with eczema, increasing to 83% during exacerbation. Even when in clinical remission, children with eczema demonstrate more sleep disturbance than healthy children. Notably, disturbed sleep in otherwise healthy children is associated with behavioural and neurocognitive deficits. Preliminary evidence suggests that disturbed sleep in children with eczema is also associated with behavioural deficits while the impact on neuropsychological functioning remains unexplored. In conclusion, a disease which affects up to 20% of children in some countries and may produce long-term behavioural and neurocognitive deficits merits further evaluation using standardised tests of sleep, behaviour and neurocognition.

Noxious Inhibition of Temporal Summation is Impaired in Chronic Tension-Type Headache

(Headache 2010;50:403‐412)

Reliability of Temporal Summation and Diffuse Noxious Inhibitory Control

BACKGROUND The test-retest reliability of temporal summation (TS) and diffuse noxious inhibitory control (DNIC) has not been reported to date. Establishing such reliability would support the possibility of future experimental studies examining factors affecting TS and DNIC. Similarly, the use of manual algometry to induce TS, or an occlusion cuff to induce DNIC of TS to mechanical stimuli, has not been reported to date. Such devices may offer a simpler method than current techniques for inducing TS and DNIC, affording assessment at more anatomical locations and in more varied research settings. METHOD The present study assessed the test-retest reliability of TS and DNIC using the above techniques. Sex differences on these measures were also investigated. RESULTS Repeated measures ANOVA indicated successful induction of TS and DNIC, with no significant differences across test-retest occasions. Sex effects were not significant for any measure or interaction. Intraclass correlations indicated high test-retest reliability for all measures; however, there was large interindividual variation between test and retest measurements. CONCLUSION The present results indicate acceptable within-session test-retest reliability of TS and DNIC. The results support the possibility of future experimental studies examining factors affecting TS and DNIC.

Further Development and Validation of the Occupational Fatigue Exhaustion Recovery (OFER) Scale

Objective: Refinement of the Occupational Fatigue Exhaustion Recovery (OFER) scale. Method: The responses of 510 nurses to the OFER scale, two of whose scales contained additional items, were examined with CFA and regression analyses. Results: Analyses of the expanded pool of items identified three subscales of 5 items each for the renamed OFER15 scale. The subscales have high internal reliability (>.84), face, construct and discriminant validity. SEM analysis confirmed the role of recovery in mediating the relationship between acute and chronic fatigue measured with the OFER15 scale. Significance: The OFER15 measure is a parsimonious scale with robust psychometric properties whose subscales distinguish well between acute fatigue states and chronic fatigue traits. The intershift recovery subscale is unique among published fatigue scales. The OFER15 is suggested as a valuable new instrument for the researchers in the work-related fatigue area, and also as screening instrument in Primary Care.

Inconsistent sleep schedules and daytime behavioral difficulties in school-aged children

OBJECTIVES Current recommendations for healthy sleep in school-aged children are predominantly focused on optimal sleep duration (9-11h). However, given the importance of routine for circadian health, the stability of sleep/wake schedules may also be important, especially for daytime behavioral functioning. We examined the relationship between short sleep duration, sleep schedule instability and behavioral difficulties in a community sample of Australian children. METHODS Children, aged 5-10 years (N=1622), without chronic health or psychological conditions, were recruited from primary schools in Adelaide, South Australia. A parent-report questionnaire was used to assess sleep/wake behavior. Behavioral functioning was assessed using the Strengths and Difficulties Questionnaire. RESULTS Most children met sleep duration recommendations with approximately 5% reporting <9h and 3% >12h. Weekly variability of bed and rise times >1h were reported in up to 50% of children. Multinomial regression analysis revealed sleep duration <10h, bedtime latency >60 min, and bed and rise time variability >60 min significantly increased the risk of scoring in the 95th percentile for behavioral sub-scales. CONCLUSIONS Inconsistent sleep schedules were common and, similar to short sleep duration, were associated with behavioral difficulties. Considering the lack of study in this area, further research is needed for the development of new recommendations, education and sleep health messages.