ORCID Profile
0000-0003-2372-5904
Current Organisation
University of Southampton
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Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.RIDD.2013.08.018
Abstract: Sleep and related maternal beliefs were assessed in a narrow age range of 18 children with Williams syndrome (WS) and 18 typically developing (TD) children. WS is a rare genetic disorder characterised by a complex physical, cognitive and behavioural phenotype. High prevalence of sleep difficulties in older children and adults with WS have been reported. Parents completed 6 questionnaires: the Brief Infant Sleep Questionnaire, Infant Sleep Vignettes Interpretation Scale, Pittsburgh Sleep Quality Index of Parents, Child Behaviour Checklist, MacArthur Communicative Development Inventory for Infants - Words and Gestures, and the Major (ICD-10) Depression Inventory. Compared to TD children, those with WS had shorter night sleep, more night wakings and wakefulness according to parental report. Regression analyses revealed that a proportion of the variance in language development scores in WS children could be explained by night sleep duration. Compared to control parents, the mothers of the WS group were more likely to describe their child's sleep as problematic and had higher rates of involvement with child sleep, yet they had a lesser tendency to interpret sleep problems as signs of distress and a greater tendency to emphasise limit setting. Approximately half of both groups of mothers experienced poor sleep quality. This was also related to maternal mood, and night wakefulness in the children with WS. This is the first study to quantify sleep difficulties in young children with WS in a narrow age range using maternal report. The possible negative effects on maternal sleep and mood, and the link between night sleep and language development in young children with WS, requires further detailed investigation.
Publisher: Elsevier BV
Date: 11-2013
Publisher: Oxford University Press (OUP)
Date: 12-2016
DOI: 10.5665/SLEEP.6316
Publisher: Oxford University Press (OUP)
Date: 05-2016
DOI: 10.5665/SLEEP.5740
Publisher: Informa UK Limited
Date: 03-10-2016
DOI: 10.1080/09297049.2016.1231298
Abstract: The objective of this study is to investigate whether sleep problems might account for the increased working memory deficits observed in school-aged children with neurological conditions. A novel, transdiagnostic approach to the investigation was chosen, and sleep is treated as a process that can potentially account for working memory difficulties across a range of neurological conditions. Prevalence estimates of sleep problems are also examined. Archival data of 237 children aged 6 to 11 years were collected from a Western Australian statewide neuropsychological service for the period 26 July 2011 to 14 January 2014. Measures of parent-reported sleep quality, snoring, and daytime sleepiness were obtained, in addition to objective measures of verbal and spatial working memory, storage capacity, and processing speed. The results of the data analysis reveal that over one third of participants reported having clinically-significant levels of sleep problems and that poor sleep quality is significantly associated with verbal working memory difficulties. This association remains after partialling out the variance contributed to performance by storage capacity and processing speed, suggesting that sleep is impacting upon an executive component of working memory. No other significant associations are observed. The results suggest that poor sleep quality is associated with an executive component of verbal (rather than spatial) working memory in children with neurological conditions. This has implications for the biological mechanisms thought to underlie the relationship between sleep and cognition in children. The results also demonstrate the clinical utility of a transdiagnostic approach when investigating sleep and cognition in children with neurological conditions.
Publisher: American Psychological Association (APA)
Date: 2014
DOI: 10.1037/NEU0000065
Abstract: To assess cognition in populations born and living at high altitude (HA 3,700 m) and low altitude (LA 500 m) in Bolivia, who were similar for both socioeconomic status and genetic ancestry. To determine whether HA hypoxia influences cognitive decline across the life span. In total, 191 healthy participants aged 4 to 85 years were assessed at HA (N = 94 33 35% male) and LA (N = 97 46, 47% male) on a battery of cognitive tasks: fluid intelligence, attention, short- and long-term memory, and psychomotor speed. Saliva s les were obtained for evaluation of genetic ancestry. HA participants were significantly slower on measures of processing speed and speed of attention than in iduals born and living at LA. HA participants had slightly higher percentage of native Andean ancestry than LA participants, but this was not associated with cognitive performance. This is the first study of HA residence and neurocognition across the life span. Given the physiological challenges of HA living, the impact on cognition appears to be subtle and related only to the speed of more complex cognitive operations, rather than to their accuracy. Moreover, the impact on cognition does not appear to differ with increasing age or for different degrees of genetic admixture. Further studies recruiting HA participants with a broader range of native Andean ancestry will help to address the issue of to what extent Amerindian ancestry provides neuroprotection to chronic hypoxia in those living at HA.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.SLEEP.2017.02.008
Abstract: Sleep-disordered breathing (SDB) is often co-morbid with conductive hearing loss in early childhood due to a shared aetiology of adenotonsillar hypertrophy. Hearing loss is independently associated with impairment of executive function and behavioural difficulties. We hypothesised that these impairments in children with SDB may be mediated through hearing loss. Fifty-eight children including 37 snorers awaiting adenotonsillectomy and 21 healthy non-snoring controls, aged 3-5 years, were assessed with pure tone audiometry, Strengths and Difficulties (SDQ), Behaviour Rating of Executive Function (BRIEF-P), and Childhood Middle Ear Disease and Hearing questionnaires. Polysomnography in snoring children generated an obstructive apnoea/hypopnea index (OAHI). Two regression models examined the effect of SDB and the mediating impact of hearing loss on BRIEF and SDQ. Snoring children had significantly poorer hearing, greater past exposure to hearing loss, and higher total SDQ and BRIEF-P scores than non-snoring controls. The first regression model, including all children, demonstrated that the impact of snoring on BRIEF_P, but not SDQ, was entirely mediated by a history of hearing loss exposure but not same-day audiometry. The second model examined snoring children only, categorising the group into 12 with obstructive sleep apnoea (OSA) (OAHI ≥ 5) and 25 without OSA. OSA had a direct effect on SDQ scores, but this was not mediated by a history of hearing loss. In early childhood, conductive hearing loss mediates the relationship between SDB, irrespective of severity, and parent report of executive function but not behaviour. Treatment of hearing loss in pre-school SDB might improve executive function.
Publisher: Informa UK Limited
Date: 16-07-2019
DOI: 10.1080/15402002.2019.1641501
Abstract: Children with Down syndrome (DS) commonly experience difficulties with executive function (EF). They are also vulnerable to obstructive sleep apnoea (OSA). OSA is associated with EF deficits in typically developing children. A recent study reported an association between OSA and cognitive deficits in 38 school-aged children with DS. We experimentally investigated EF behaviours in young children with DS, and their association with OSA. Children with DS were recruited to take part in a larger study of OSA (N = 202). Parents of 80 children (50 male) aged 36 to 71 months ( Obstructive apnoea/hypopnoea index was in the normal range (0-1.49/h) for 28 children but indicated OSA (≥1.5/h) in 41 children. Consistent with previous research, we found a large effect for children experiencing particular weaknesses in working memory, planning and organising, whilst emotional control was a relative strength. OSA was associated with poorer working memory (β = .23, R2 = .05, Findings suggest that known EF difficulties in DS are already evident at this young age. Children with DS already have limited cognitive reserve and can ill afford additional EF deficit associated with OSA. OSA is amenable to treatment and should be actively treated in these children to promote optimal cognitive development.
Publisher: Oxford University Press (OUP)
Date: 13-09-2018
DOI: 10.1093/SLEEP/ZSY181
Abstract: We aimed to characterize heart-rate variability (HRV) during sleep in Andean children native to high altitude (HA) compared with age, gender, and genetic ancestry-similar low-altitude (LA) children. We hypothesized that the hypoxic burden of sleep at HA could induce variation in HRV. As children have otherwise healthy cardiovascular systems, such alterations could provide early markers of later cardiovascular disease. Twenty-six LA (14F) and 18 HA (8F) children underwent a single night of attended polysomnography. Sleep parameters and HRV indices were measured. Linear mixed models were used to assess HRV differences across sleep stage and altitude group. All children showed marked fluctuations in HRV parameters across sleep stages, with higher vagal activity during nonrapid eye movement sleep and greater variability of the heart rate during rapid eye movement (REM). Moreover, HA children showed higher very low-frequency HRV in REM sleep and, after adjusting for heart rate, higher low-to-high frequency ratio in REM sleep compared with children living at lower altitude. We confirmed previous findings of a stage-dependent modulation of HRV in Andean children living at both HA and LA. Moreover, we showed subtle alteration of HRV in sleep in HA children, with intriguing differences in the very low-frequency domain during REM sleep. Whether these differences are the results of an adaptation to high-altitude living, or an indirect effect of differences in oxyhemoglobin saturation remains unclear, and further research is required to address these questions.
Publisher: American Academy of Pediatrics (AAP)
Date: 07-2007
Publisher: Wiley
Date: 15-04-2013
DOI: 10.1111/DMCN.12149
Abstract: Night-time postural equipment (NTPE) can prevent hip subluxation in children with severe motor disorders (SMDs). However, it is unclear how it affects ventilatory function. The aims of the study were to determine how NTPE use affects ventilatory function and to compare night-to-night variability of ventilatory function in children with SMDs and typically developing healthy children. Fifteen NTPE users (six males, nine females), aged 1 to 19 years (mean age 8y 7mo) alternated sleep condition between NTPE and sleeping unsupported for 14 nights. In all but two participants, gross motor function was classified as Gross Motor Function Classification System (GMFCS) level V in the other two it was level IV. Oxyhaemoglobin saturation (SpO2 ) was monitored each night and transcutaneous CO2 (PtcCO2 ) for one night in each sleep condition. In 17 healthy children of similar age, home SpO2 only was monitored for seven nights. In 13 of 15 NTPE users and 12 of the 17 typically developing children, SpO2 monitoring was satisfactorily completed. Of the children with SMDs, two had mean SpO2 levels below the treatment threshold for supplemental oxygen, which was uniquely associated with use of NTPE in only one participant, and three had nocturnal hypoventilation, which was uniquely associated with NTPE use in only one case. Night-to-night SpO2 variability was higher in children with SMDs than in typically developing children. NTPE may impair or enhance ventilatory function in a minority of children. Owing to night-to-night variability in SpO2 , at least three nights of monitoring are recommended to determine optimal positioning for effective ventilation before and after NTPE introduction.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Catherine Hill.