Sleep disruption in toddlers with Down syndrome may affect behavior

August 2, 2012 By Ursula Tooley and La Monica Everett-Haynes
Undergraduate researcher Ursula Tooley is working with the UA's Down Syndrome Research Group to study the effects of sleep disruption on cognition and behavior in children with Down syndrome. (Photo credit: Beatriz Verdugo/UANews)

(Medical Xpress) -- In typically developing children, links between behavioral issues and disrupted sleep have been well-researched, though fewer studies have focused on understanding how early sleep disruption affects children with Down syndrome.

At the University of Arizona, undergraduate researcher Ursula Tooley is working with a team to fill the gap in the literature to one day help improve treatment.

Children with have long been identified as a population at risk for -related disorders. But it now seems that sleep disturbance can have an effect on early development, said Tooley, a member of the UA's Down Syndrome Research Group.

Tooley has been investigating a preschool population of children who have Down syndrome, and her study has indicated that the effect of disrupted sleep may begin to influence behavior and in children with Down syndrome who are as young as age 2.

“Sleep is much more important than most people realize,” said Tooley, a neuroscience major and Honors College student. “Many of these children are clearly having difficulty sleeping, and it’s rewarding to be able to provide parents with another avenue of possible treatment for their child.”

Down syndrome is caused by an extra copy of the 21st human chromosome and affects approximately one out of every 600 children born in the U.S. The condition is characterized by delayed development, specific cognitive difficulties and a particular set of physical characteristics. These characteristics, such as decreased muscle tone, contribute to an increase in the probability of sleep apnea.

“Parents of children with Down syndrome should be on the lookout for sleep problems at an early age," said Tooley, also is a student with the UA Undergraduate Biology Research Program, UBRP, and became involved in the lab through the program.

Tooley works under the direction of Drs. Jamie Edgin and Regents' Professor Lynn Nadel, both UA psychologists who lead the research group. In earlier studies, the UA Down Syndrome Research Group found in studying children with Down syndrome that there exists an increase in sleep problems with age. The group also has found connections between memory deficits and sleep apnea.

"She found preliminary correlations between sleep and behavior scores across a number of measures that were quite striking," Edgin, a UA assistant professor of psychology, said of Tooley's work, noting that while the research group gathered the data, Tooley stepped in to complete the analysis.

"In general, sleep is underrecognized as an issue in pediatric populations. We're only starting to understand how sleep may contribute to brain development and delays in brain development over and beyond Down syndrome," Edgin said.

Edgin said current guidelines suggest screening children at age 4, though some doctors and researchers would prefer that to occur much earlier to help prevent future problems.

"Across a person's lifespan, they could be taking an additional hit because of sleep disruption," she added. "It may be easier to treat these children if we get them on the treatment that they need at 18 months to 2-years old rather than a teeanger."

Thus, Tooley's findings provide an important addition to the existing gap in the , she said, adding that the team will be pursuing publication in the future. Edgin presented the preliminary findings to an audience of more than 100 doctors and other medical professionals during the recent National Down Syndrome Medical Interest Group meeting in Washington, D.C.

"When completed, Ursula’s study will provide us with evidence to say that we need to begin screenings and treatments much earlier than we currently do," Edgin said.

In the lab,Tooley performs polysomnograms, which record various physiological variables such as the brain’s activity and eye movements during sleep and allow for the determination of sleep patterns.

Actigraphy, a method of measuring movement that uses a wristband worn during sleep, also is used to evaluate sleep in younger children – toddlers ages 2-5, which is rare in research – to determine the degree of their sleep disturbance over a period of several days, as measured by what is called a fragmentation index.

The fragmentation index is an indicator of how much the child moves during sleep, and thus how often their sleep is disturbed by physical movement or awakenings. In Tooley' study, a higher fragmentation index was associated with both a lower working memory function and an increase in general maladaptive behavior, such as aggression toward others, noncompliance or hyperactivity.

“This increase in restlessness could be caused by Down syndrome-induced sleep apnea or more general , but regardless of the origin, addressing it could lead to improved outcomes for the child,” Tooley said.

Tooley said her initial findings provide hope for parents and caregivers, as early diagnosis and treatment of sleep disorders may help to alleviate some of the behavioral and memory deficits associated with Down syndrome.

"One of the main concerns of parents with with Down syndrome is how they can mitigate the effects and better incorporate their child into society," Tooley said. "Any insight we can gain into the workings of what contributes to behavioral and cognitive issues provides another avenue for positive treatments. It's something parents can take into account when considering their child's health."

Explore further: Parents' conflicts affect adopted infants' sleep

Related Stories

Parents' conflicts affect adopted infants' sleep

August 2, 2011
When parents fight, infants are likely to lose sleep, researchers report. "We know that marital problems have an impact on child functioning, and we know that sleep is a big problem for parents," said Jenae M. Neiderhiser, ...

Sleep breathing machine shows clear benefits in children with sleep apnea

February 10, 2012
Children and adolescents with obstructive sleep apnea had substantial improvements in attention, anxiety and quality of life after treatment with positive airway pressure (PAP)—a nighttime therapy in which a machine ...

Pediatric epilepsy impacts sleep for the child and parents

May 17, 2012
Researchers from Massachusetts General Hospital for Children in Boston have determined that pediatric epilepsy significantly impacts sleep patterns for the child and parents. According to the study available in Epilepsia, ...

Recommended for you

Four simple tests could help GPs spot pneumonia and reduce unnecessary antibiotics

November 23, 2017
Testing for fever, high pulse rate, crackly breath sounds, and low oxygen levels could be key to helping GPs distinguish pneumonia from less serious infections, according to a large study published in the European Respiratory ...

New approach to tracking how deadly 'superbugs' travel could slow their spread

November 22, 2017
Killer bacteria - ones that have out-evolved our best antibiotics—may not go away anytime soon. But a new approach to tracking their spread could eventually give us a fighting chance to keep their death toll down.

Research points to diagnostic test for top cause of liver transplant in kids

November 22, 2017
Biliary atresia is the most common cause of liver transplants for children in the United States. Now researchers report in Science Translational Medicine finding a strong biomarker candidate that could be used for earlier ...

Metabolites altered in chronic kidney disease

November 22, 2017
Chronic kidney disease (CKD) affects 1 in 7 people in the United States, according to the U.S. National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK). These individuals have a very high risk of cardiovascular ...

Alcohol consumption and metabolic factors act together to increase the risk of severe liver disease

November 22, 2017
A new study provides insights into the interaction between alcohol consumption and metabolic factors in predicting severe liver disease in the general population. The findings, which are published in Hepatology, indicate ...

Rainfall can indicate that mosquito-borne epidemics will occur weeks later

November 22, 2017
A new study demonstrates that outbreaks of mosquito-borne viruses Zika and Chikungunya generally occur about three weeks after heavy rainfall.Researchers also found that Chikungunya will predominate over Zika when both circulate ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.