The Paediatric Narcolepsy Project: The relationships between sleep, physical activity, cognitive function and psychosocial well-being in children with narcolepsy

Narcolepsy is a lifelong neurological sleep disorder characterised by excessive daytime sleepiness and attacks of muscle weakness triggered by emotions (cataplexy). In 2010, alarms were raised about an increase in the incidence rate of narcolepsy diagnosis in children. Subsequent research has confirmed a causal link between the use of the Pandemrix H1N1 influenza vaccine and cases of narcolepsy in children. Despite the rise in cases, there is limited research investigating the clinical characterisation and functional impact of paediatric narcolepsy. To address this gap in the literature, a systematic review of cognitive function and psychosocial well-being in children with narcolepsy was conducted. The results suggested that children who develop narcolepsy are at significant risk of cognitive impairment in at least one domain and emotional problems including depression, anxiety and low self-esteem. Based on the systematic review findings, a case-control study was designed to describe the relationships between sleep, physical activity, cognitive function and psychological well-being in children with narcolepsy. 23 children with narcolepsy (aged 8-15 years) and 23 gender, age, I.Q and socioeconomic status (SES) matched healthy controls underwent standardized neuropsychological assessment and home polysomnography (PSG) using a portable PSG system. The children also wore an actigraphy monitor for eight days to measure their daytime sleep and physical activity. 21 out of the 23 children with narcolepsy were treated with medication at the time of the study. Children with narcolepsy showed more sleep disturbance, spent more time asleep during the day and were less active when awake than controls. Children with narcolepsy reported more feelings of anger and more disruptive behaviour than controls. Children with narcolepsy also reported poorer health-related quality of life than controls. There were no significant differences found in cognitive performance between the two groups, suggesting that well-managed children with narcolepsy do not have significantly impaired cognitive function. Sleep efficiency positively correlated with physical activity and health-related quality of life in children with narcolepsy and controls. Physical activity positively correlated with health-related quality of life and negatively correlated with disruptive behaviour in children with narcolepsy and controls. These findings will inform the design of intervention studies that aim to optimise the clinical management of paediatric narcolepsy.