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Do Infant Motor Skills Mediate the Association Between Positional Plagiocephaly/Brachycephaly and Cognition in
Brent R Collett1,2, Erin R Wallace2, Cindy Ola1,2
1Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, USA.
Insights
Infant motor skills partially explain the link between positional plagiocephaly/brachycephaly (PPB) and lower cognitive scores in children. Early motor skill monitoring and intervention can support development in infants with PPB.
Area of Science:
- Developmental Pediatrics
- Neuroscience
- Child Psychology
Background:
- Positional plagiocephaly/brachycephaly (PPB) is linked to diminished cognitive function in school-aged children.
- The mediating role of infant motor skills in this association has not been previously established.
Purpose of the Study:
- To investigate whether infant motor skills mediate the relationship between PPB and cognitive scores in later childhood.
- To analyze the specific contributions of fine and gross motor skills to this mediation.
Main Methods:
- Longitudinal study tracking 187 children with PPB and 149 controls from infancy to age 9.
- Assessment of infant motor skills using the Bayley Scales of Infant and Toddler Development (Bayley-3).
- Evaluation of cognitive abilities using the Differential Ability Scales (DAS-2), including general cognitive ability (GCA).
Main Results:
- Children with PPB exhibited lower DAS-2 GCA scores compared to controls.
- Infant motor skills significantly mediated the association between PPB and cognitive scores, accounting for approximately 33% of the difference.
- Gross motor skills demonstrated a stronger mediating effect than fine motor skills.
Conclusions:
- Infant motor skills partially mediate the association between PPB and cognitive outcomes in school-aged children.
- Monitoring and intervening in motor development may mitigate cognitive concerns for children with PPB.
- Early motor development is crucial for overall developmental trajectories in children with PPB.
Objective:
Positional plagiocephaly/brachycephaly (PPB) is associated with lower cognitive scores in school-aged children. This study tested the hypothesis that infant motor skills mediate this association.
Methods:
Children with a history of PPB (cases, n = 187) and without PPB (controls, n = 149) were followed from infancy through approximately 9 years of age. Infant motor skills were assessed using the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-3), and cognition was assessed using the Differential Ability Scales, 2nd edition (DAS-2). The Bayley-3 motor composite was examined as a mediator of the association between PPB and DAS-2 general cognitive ability (GCA) scores. In secondary analyses, mediation models were examined for the DAS-2 verbal ability, nonverbal ability, and working memory scores; models using the Bayley-3 fine versus gross motor scores also were examined.
Results:
Cases scored lower than controls on the DAS-GCA (β = -4.6; 95% CI = -7.2 to -2.0), with an indirect (mediated) effect of β = -1.5 (95% CI = -2.6 to -0.4) and direct effect of β = -3.1 (95% CI = -5.7 to -0.5). Infant motor skills accounted for approximately 33% of the case-control difference in DAS-2 GCA scores. Results were similar for other DAS-2 outcomes. Evidence of mediation was greater for Bayley-3 gross motor versus fine motor scores.
Conclusion:
Infant motor skills partially mediate the association between PPB and cognition in school-aged children. Monitoring motor development and providing intervention as needed may help offset associated developmental concerns for children with PPB.
Impact:
To our knowledge, this study is the first longitudinal investigation of the development of children with and without PPB from infancy through the early school years and the first to examine motor skills as a mediator of cognitive outcomes in this population. The findings highlight the importance of early motor skills for other developmental outcomes.
Lay Summary:
Infants' motor skills are related to the development of PPB and its association with later cognition. If your child has PPB, physical therapists may have an important role in assessing and providing treatment to promote motor development.
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