2.0 CE Credits - Special Issue: The Neuropsychology of Neurodevelopmental Disorders III

2.0 Hours of Continuing Education credits are available for reading this series. You must read ALL listed critical reviews below in order to receive credit, and you must pass the evaluation with a score of at least 75%.

On this page you may review the learning objectives for this series, as well as the titles, authors, and abstracts for each critical review.

CLICK HERE to view this overall issue on the Cambridge University Press website.

LEARNING OBJECTIVES FOR THIS SERIES:

At the completion of reading these materials, learners will be able to:
  1. Discuss executive function skills documented in children with neurofibromatosis type 1.
  2. Describe moderator variables of executive function skills in children with in neurofibromatosis type 1.
  3. Describe the course of cortical development within a developmental context in pediatric Down syndrome.
  4. Discuss current limitations and future directions critical for future work in this field (i.e., the field of pediatric Down syndrome).
  5. Discuss the relationship between a molecular lesion approach to dystrophinopathy and cognition.
  6. Explain how individual capacity as opposed to IQ in isolation may be a better predictor of academic achievement.
  7. Describe the memory deficits associated with Down syndrome.
  8. Discuss procedures for learning new words, including fast mapping and explicit encoding.

Individual Article Titles And Authors:

Systematic Review and Meta-analysis of Executive Functions in Preschool and School-Age Children With Neurofibromatosis Type 1

Marie-Laure Beaussart, Sébastien Barbarot, Claire Mauger, AND Arnaud Roy

Objectives: Neurofibromatosis type 1 (NF1) is a genetic disorder in which the most frequent complication in children is learning disabilities. Over the past decade, growing arguments support the idea that executive dysfunction is a core deficit in children with NF1. However, some data remain inconsistent. The aim of this study was to determine the magnitude of impairment for each executive function (EF) and clarify the impact of methodological choices and participant’s characteristics on EFs. Methods: In this meta-analysis, 19 studies met the selection criteria and were included with data from a total of 805 children with NF1 and 667 controls. Based on the Diamond’s model (2013), EF measures were coded separately according to the following EF components: working memory, inhibitory control, cognitive flexibility, planning/ problem solving. The review protocol was registered with PROSPERO (International prospective register of systematic reviews; CRD42017068808). Results: A significant executive dysfunction in children with NF1 is demonstrated. Subgroup analysis showed that the impairment varied as a function of the specific component of executive functioning. The effect size for working memory and planning/problem solving was moderate whereas it was small for inhibitory control and cognitive flexibility. Executive dysfunction seems to be greater with increasing age whereas assessment tool type, intellectual performance, attention deficit hyperactivity disorder and control group composition did not seem to affect EF results. Conclusions: EF deficits are a core feature in children with NF1 and an early identification of executive dysfunctions is essential to limit their impact on the quality of life. (JINS, 2018, 24, 977–994)

Pediatric Brain Development in Down Syndrome: A Field in Its Infancy

Taralee Hamner, Manisha D. Udhnani, Karol Z. Osipowicz, AND Nancy Raitano Lee

Objectives: As surprisingly little is known about the developing brain studied in vivo in youth with Down syndrome (DS), the current review summarizes the small DS pediatric structural neuroimaging literature and begins to contextualize existing research within a developmental framework. Methods: A systematic review of the literature was completed, effect sizes from published studies were reviewed, and results are presented with respect to the DS cognitive behavioral phenotype and typical brain development. Results: The majority of DS structural neuroimaging studies describe gross differences in brain morphometry and do not use advanced neuroimaging methods to provide nuanced descriptions of the brain. There is evidence for smaller total brain volume (TBV), total gray matter (GM) and white matter, cortical lobar, hippocampal, and cerebellar volumes. When reductions in TBV are accounted for, specific reductions are noted in subregions of the frontal lobe, temporal lobe, cerebellum, and hippocampus. A review of cortical lobar effect sizes reveals mostly large effect sizes from early childhood through adolescence. However, deviance is smaller in adolescence. Despite these smaller effects, frontal GM continues to be largely deviant in adolescence. An examination of age-frontal GM relations using effect sizes from published studies and data from Lee et al. (2016) reveals that while there is a strong inverse relationship between age and frontal GM volume in controls across childhood and adolescence, this is not observed in DS. Conclusions: Further developmentally focused research, ideally using longitudinal neuroimaging, is needed to elucidate the nature of the DS neuroanatomic phenotype during childhood and adolescence. (JINS, 2018, 24, 966–976)

Executive Skills and Academic Achievement in the Dystrophinopathies

Robert J. Fee, Jacqueline Montes, Jennifer L. Stewart, AND Veronica J. Hinton

Objectives: To examine academic performance in dystrophinopathy as a function of dystrophin gene mutation position as well as intellectual function, executive skills, socioeconomic status (SES), behavior, and physical ability. Methods: In a cross-sectional study, boys with dystrophinopathy (ages 5–17; n= 50) completed tests of academics (Woodcock-Johnson- III: spelling, reading, calculation and total scores), executive functioning (selective attention/inhibitory control, set shifting, working memory, and processing speed), single word comprehension and nonverbal reasoning. Motor skills were assessed and parents provided demographic information and child behavioral assessments. Dystrophin gene mutation positions were dichotomized into groups (upstream versus downstream of exon 43, location of isoforms previously linked to intellectual impairment). Genetic mutation groups were compared on measures of academic achievement, and multiple regression analyses examined unique and joint contributions of executive skills, intelligence quotient (IQ), SES, motor abilities, behavior, and mutation positions to academic outcomes. Results: Academic performance was slightly, yet significantly, lower than IQ and varied as a function of dystrophin gene position, wherein boys possessing the downstream mutation exhibited greater impairment than boys with the upstream mutation. Digit span forward (indexing verbal span), but no other measure of executive function, contributed significant variance to total academic achievement, spelling and calculation. Conclusions: Weak academic performance is associated with dystrophinopathy and is more common in downstream mutations. A specific deficit in verbal span may underlie inefficiencies observed in children with dystrophinopathy and may drive deficits impacting academic abilities. (JINS, 2018, 24, 928–938)

Small Sets of Novel Words Are Fully Retained After 1-Week in Typically Developing Children and Down Syndrome: A Fast Mapping Study

Stella Sakhon, Kelly Edwards, Alison Luongo, Melanie Murphy, AND Jamie Edgin

Objectives: Down syndrome (DS) is a population with known hippocampal impairment, with studies showing that individuals with DS display difficulties in spatial navigation and remembering arbitrary bindings. Recent research has also demonstrated the importance of the hippocampus for novel word-learning. Based on these data, we aimed to determine whether individuals with DS show deficits in learning new labels and if they may benefit from encoding conditions thought to be less reliant on hippocampal function (i.e., through fast mapping). Methods: In the current study, we examined immediate, 5-min, and 1-week delayed word-learning across two learning conditions (e.g., explicit encoding vs. fast mapping). These conditions were examined across groups (twenty-six 3- to 5-year-old typically developing children and twenty-six 11- to 28-year-old individuals with DS with comparable verbal and nonverbal scores on the Kaufman Brief Intelligence Test – second edition) and in reference to sleep quality. Results: Both individuals with and without DS showed retention after a 1-week delay, and the current study found no benefit of the fast mapping condition in either group contrary to our expectations. Eye tracking data showed that preferential eye movements to target words were not present immediately but emerged after 1-week in both groups. Furthermore, sleep measures collected via actigraphy did not relate to retention in either group. Conclusions: This study presents novel data on long-term knowledge retention in reference to sleep patterns in DS and adds to a body of knowledge helping us to understand the processes of word-learning in typical and atypically developing populations. (JINS, 2018, 24, 955–965)