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Assessment of sleep in children with mucopolysaccharidosis type III
Louise Victoria Mahon1, Michelle Lomax1, Sheena Grant1
1Division of Clinical Psychology, University of Manchester, Manchester, United Kingdom.
Insights
Children with mucopolysaccharidosis Type III (MPS III) experience significant sleep difficulties, including longer sleep onset latency and altered circadian rhythms. Objective measures like actigraphy confirm these sleep problems, suggesting targeted interventions.
Area of Science:
- Pediatric Neurology
- Sleep Medicine
- Rare Genetic Disorders
Background:
- Sleep disturbances are common in mucopolysaccharidosis Type III (MPS III), a rare lysosomal storage disorder.
- Objective, ecologically valid data on sleep quantity, quality, and circadian rhythm in MPS III are lacking.
- Understanding sleep patterns is crucial for managing the overall health and well-being of individuals with MPS III.
Purpose of the Study:
- To objectively assess sleep quantity, quality, and circadian rhythm in children with MPS III compared to typically developing controls.
- To investigate the relationship between age and sleep parameters in the MPS III cohort.
- To evaluate the potential of actigraphy and melatonin analysis in characterizing sleep disturbances in MPS III.
Main Methods:
- Actigraphy was used for 7-10 days/nights to monitor sleep patterns in eight children with MPS III and eight age-matched controls.
- Saliva samples were collected to analyze endogenous melatonin levels, assessing circadian rhythm.
- Parents completed sleep questionnaires and daily sleep diaries to supplement objective data.
Main Results:
- Children with MPS III exhibited significantly longer sleep onset latencies and increased daytime sleep compared to controls.
- Night-time sleep duration did not differ between groups, but sleep efficiency declined and sleep onset latency increased with age in MPS III.
- MPS III patients reported more sleep difficulties across all domains, and melatonin analysis indicated altered circadian systems.
Conclusions:
- Objective actigraphy and subjective reports confirm significant sleep disturbances in children with MPS III.
- Alterations in the circadian system, suggested by melatonin levels, warrant interventions to synchronize sleep-wake cycles.
- Actigraphy is a well-tolerated and recommended tool for assessing treatment efficacy in clinical practice and research for MPS III.
Abstract:
Sleep disturbances are prevalent in mucopolysaccharidosis Type III (MPS III), yet there is a lack of objective, ecologically valid evidence detailing sleep quantity, quality or circadian system. Eight children with MPS III and eight age-matched typically developing children wore an actigraph for 7-10 days/nights. Saliva samples were collected at three time-points on two separate days, to permit analysis of endogenous melatonin levels. Parents completed a sleep questionnaire and a daily sleep diary. Actigraphic data revealed that children with MPS III had significantly longer sleep onset latencies and greater daytime sleep compared to controls, but night-time sleep duration did not differ between groups. In the MPS III group, sleep efficiency declined, and sleep onset latency increased, with age. Questionnaire responses showed that MPS III patients had significantly more sleep difficulties in all domains compared to controls. Melatonin concentrations showed an alteration in the circadian system in MPS III, which suggests that treatment for sleep problems should attempt to synchronise the sleep-wake cycle to a more regular pattern. Actigraphy was tolerated by children and this monitoring device can be recommended as a measure of treatment success in research and clinical practice.
