For both generally developing toddlers and children with various neurodevelopmental disorders, sleep issues have been found to harm language development and behavior. For children with Williams syndrome (WS), the relationship between sleep characteristics and topics and language and behavior is unclear. The purpose of the research was to determine these relationships in 2-year-olds with WS. Researchers reviewed the links between nonverbal reasoning ability, nocturnal sleep duration, and excessive daytime sleepiness with linguistic ability and behavior problems. A total of 96, two-year-olds with classic-length WS deletions were included in the survey. To examine sleep characteristics and difficulties, parents filled out the Pediatric Sleep Questionnaire, which contains a Sleep-Related Breathing Disorder (SRBD) scale with a subscale evaluating excessive daytime drowsiness. To assess behavior problems and expressive vocabulary, parents additionally completed the Child Behavior Checklist (CBCL) and the MacArthur-Bates Communicative Development Inventory: Words and Sentences. The Mullen Scales of Early Learning assessed children’s nonverbal thinking and language abilities. Children slept an average of 10.36 hours per night (SD=1.09, range7.3–13.3), which did not differ substantially from the mean reported by Bell and Zimmerman (2010) for typically developing toddlers (P=.787). SRBD was found in 16% of the subjects, while excessive daytime drowsiness was determined in 30%. On all CBCL scales, children who tested positive for SRBD had considerably more behavior difficulties than children who tested negative. Children who slept excessively during the day showed significantly higher levels of attention/hyperactivity, tension, and externalizing challenges than children who did not sleep excessively during the day. Individual variations in expressive language, receptive language, and internalizing issues were accounted for by differences in parent-reported nocturnal sleep duration and directly evaluated nonverbal reasoning ability. Individual differences in daytime drowsiness reported by parents accounted for differences in externalizing issues. In toddlers with WS, the relationships between nocturnal sleep duration, positive SRBD screens, and excessive daytime drowsiness and language and behavior are similar to those in typically developing toddlers. The need to evaluate young children with WS for sleep disorders is highlighted by these findings. There is a need for more research into the effectiveness of behavioral treatments for increasing sleep in children with WS.
Link:link.springer.com/article/10.1186/s11689-020-09336-z
