Motor and cognitive development of children with Down syndrome: The effect of acquisition of walking skills on their cognitive and language abilities

Motor-language links in children with Down syndrome: a scoping review to revisit the literature with a developmental cascades lens

Background

Children with Down syndrome (DS) typically have motor and language needs. Improving function is a shared goal for the rehabilitation therapy team, however physical therapy, occupational therapy, and speech-language pathology professionals treat patients differently. This difference in care may mask developmental cascades whereby changes in one domain (e.g., motor) can have seemingly unexpected effects on another domain (e.g., language).

Objective

This scoping review identified papers where motor and language data have been reported together in children with DS and reinterpreted findings from a developmental cascades lens.

Design

Online databases were used to identify 413 papers published before October 2021 from which 33 papers were retained that reported both motor (gross and/or fine) and language (expressive and/or receptive) data in individuals with DS with a chronological age of 0-18 years.

Results

The majority of papers (79%) that reported motor and language data in children with DS did not examine their link, while 12% analyzed motor-language links, but using a cross-sectional or retrospective design. Only three papers (9%) utilized a longitudinal design to examine predictive links.

Conclusion

Motor functioning and language functioning have often been reported together, but not analyzed together, in studies of children with DS. The few studies that did analyze motor-language links largely replicated findings from other developmental populations where motor gains were positively linked to language gains. Analyzing links between domains when such data is available is needed to fully characterize developmental cascades in DS and may have broad clinical implications.

Effects of thalamic and basal ganglia deep brain stimulation on language-related functions - Conceptual and clinical considerations

Deep Brain Stimulation (DBS) is a therapy for various neurological movement disorders. It acts predominantly on motor symptoms, but may unfold a number of mostly subtle cognitive effects. In this regard, reports on particular language-related DBS sequels are comparably frequent, but difficult to overlook, given the heterogeneity of targeted structures in the brain, treated diseases, assessment methods and results reported. Accordingly, available knowledge was organized with respect to important aspects, such as the main DBS loci and surgical versus neuromodulatory therapy actions. Current views of biolinguistic underpinnings of the reviewed data, their clinical relevance and potential implications are discussed.

Cognitive profiles in children and adolescents with Down syndrome

The Down syndrome (DS) phenotype is usually characterized by relative strengths in non-verbal skills and deficits in verbal processing, but high interindividual variability has been registered in the syndrome. The goal of this study was to explore the cognitive profile, considering verbal and non-verbal intelligence, of children and adolescents with DS, also taking into account interindividual variability. We particularly aimed to investigate whether this variability means that we should envisage more than one cognitive profile in this population. The correlation between cognitive profile and medical conditions, parents’ education levels and developmental milestones was also explored. Seventy-two children/adolescents with DS, aged 7–16 years, were assessed with the Wechsler Preschool and Primary Scale of Intelligence-III. Age-equivalent scores were adopted, and Verbal and Non-Verbal indices were obtained for each individual. The cognitive profile of the group as a whole was characterized by similar scores in the verbal and non-verbal domain. Cluster analysis revealed three different profiles, however: one group, with the lowest scores, had the typical profile associated with DS (with higher non-verbal than verbal intelligence); one, with intermediate scores, had greater verbal than non-verbal intelligence; and one, with the highest scores, fared equally well in the verbal and non-verbal domain. Three cognitive profiles emerged, suggesting that educational support for children and adolescents with DS may need to be more specific.

The interaction of fine motor, gesture, and structural language skills: The case of autism spectrum disorder

Motor skill differences have been consistently reported in individuals with ASD. Associations between motor skill and social communication skills have been reported in both typical development (TD) and autism spectrum disorder (ASD). The current study extends these findings to characterize performance on a fine motor imitation task, probing skills as a predictor of social and communicative functioning, and co-speech gesture use. These research questions were addressed by a secondary analysis of data collected during a previous study characterizing a cohort of individuals who were diagnosed with ASD in early childhood but lost the autism diagnosis (LAD) by the time of adolescence. Fine motor imitation skills were compared between 14 individuals with LAD, 15 individuals with autism spectrum disorder (ASD), and 12 typically developing (TD) individuals. LAD and TD groups had more advanced fine motor imitation skills than the ASD group, and abilities were significantly associated with ASD symptoms and amount of gesture use (though there was a counterintuitive interaction between group and fine motor skill in the LAD and TD groups only, in which lower motor skills predicted more ASD symptoms; this relationship was of a small effect size and is likely driven by the compressed range of fine motor skills in these two groups). Findings suggest that fine motor skills normalize along with social communication skills and restricted and repetitive behaviors and interests in individuals who lose the ASD diagnosis, and that individuals with better fine motor abilities produce more co-speech gesture.

Aging Effect on Manipulative Skills in Individuals With Down Syndrome

Deficits in motor performance have been well documented in individuals with Down syndrome (DS). However, only a few studies have focused on manipulative skills and older adults in this population. Given the associations between manipulative skills and daily living activities, more work is needed to examine the aging effect on individuals with DS. A total of 54 adults with DS participated in this study. The results indicated that older participants showed more lateralization than younger participants. They exhibited superior dominant hand preference compared to younger participants. In addition, participants with DS with high verbal ability had better performance in manual dexterity and handgrip force. Therefore, in the clinical setting, assessing mental age may help in identifying individuals with DS at a higher risk of motor impairment. Future work should examine additional determinants with a large sample size to understand the development of manipulative skills in individuals with DS. Furthermore, additional studies are needed to investigate the associations between mental age and other cognitive functions and motor performance in this population.

Is the Age of Developmental Milestones a Predictor for Future Development in Down Syndrome?

Down Syndrome (DS) is the most common genetic alteration responsible for intellectual disability, which refers to deficits in both intellectual and adaptive functioning. According to this, individuals with Down Syndrome (DS) reach developmental milestones (e.g., sitting, walking, and babbling) in the same order as their typically developing peers, but later in life. Since developmental milestones are the first blocks on which development builds, the aims of the current study are to: (i) expand the knowledge of developmental milestone acquisition; and (ii) explore the relationship between developmental milestone acquisition and later development. For this purpose 105 children/adolescents with DS were involved in this study, divided in two groups, Preschoolers (n = 39) and School-age participants (n = 66). Information on the age of acquisition of Sitting, Walking, Babbling, and Sphincter Control was collected, together with cognitive, motor, and adaptive functioning. Sitting predicted later motor development, but, with age, it became less important in predicting motor development in everyday life. Babbling predicted later language development in older children. Finally, Sphincter Control emerged as the strongest predictor of motor, cognitive, language, and adaptive skills, with its role being more evident with increasing age. Our data suggest that the age of reaching the milestones considered in the study has an influence on successive development, a role that can be due to common neural substrates, the environment, and the developmental cascade effect.