Ida Sue Baron

Delis-Kaplan Executive Function System

Executive function (EF) is a global, umbrella construct that has received considerable attention from clinicians and researchers in recent years. One result of such scrutiny is recognition of the varied ways intact or impaired EF may be demonstrated on formal neuropsychological evaluation. As a result of a variety of theoretical perspectives and consequent cumulative empirical and clinical data, the fractionation of EF into subdomains has become routine, with certain capacities such as inhibition, working memory, mental shifting, and cognitive flexibility receiving special and deserved attention. Other defined broad or narrow subdomains are of interest, as are how one complements another or is singularly crucial to understanding an individual’s behavior. Interest in assessing EF has led to the development of test instruments and scoring procedures that are believed to have a high probability of validly measuring EF competence. Determining whether the resulting good or poor scores are generalizable to a real-world environment is one of the biggest challenges we face in understanding this multispectrum cognitive function whose neuroanatomical connections are acknowledged to be within a widely distributed neural network. Further complicating EF assessment are the potential inconsistencies between how an adult and a child will manifest patterns of executive dysfunction. It is a difficult undertaking to measure discrete effects of rapid and ongoing maturational development, a dynamic process that complicates the ability to disentangle true EF strengths or weaknesses from other plausible and valid etiological factors. Additionally, which measures will have the highest sensitivity and specificity for the most efficacious EF assessment is an active, ongoing exploratory process, along with whether new measures or established measures with updated scoring modifications may prove most valuable. The Delis–Kaplan Executive Function System (D–KEFS) arrives into this mix of diverse test instruments and provides a co-normed assortment of existing measures, or newly modified established tests, which crosses modalities and covers a wide age range. The D–KEFS in its entirety includes 9 ‘‘stand-alone tests’’ and provides normative data appropriate for those 8to 89-years old for 8 of these. Normative data for the ninth, Proverb, subtest does not begin until 16 years old. The D–KEFS presents age stratified normative data (N1⁄4 1750) based on the 2000 U.S. Census figures. Additionally, a sample of 101 individuals aged 9–74 years provided test-retest data for a mean of 25 days. Comparisons are made with the California Verbal Learning Test-II and the Wisconsin Card Sorting Test. Each D–KEFS subtest is described along with its ‘‘key executive functions assessed’’, yet it should be noted that the D–KEFS manual

Attention-Deficit/Hyperactivity Disorder: A Neuropsychological Perspective Towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.

Visuospatial and verbal fluency relative deficits in 'complicated' late-preterm preschool children.

BACKGROUND Late-preterm children constitute a majority of all preterm deliveries (75%). Their immature brain development at birth has been associated with an increased risk for morbidities. Data have been sparse regarding neuropsychological outcomes in the preschool years. AIM To examine general cognition, attention/working memory, language, manual coordination/motor dexterity, visuomotor, visuospatial, and executive functions in preschoolers born late-preterm (LPT; 34-36 gestational weeks) who required NICU admission compared to term-born participants. DESIGN Single-center retrospective cohort study of 95 three-year-old children; 60 born LPT in 2004-2005 and admitted to the NICU compared to 35 healthy term-born participants born > or =37 gestational weeks and > or =2500 g. RESULTS LPT birth was associated with visuospatial (p=.005), visuomotor (p=.012), and executive function (noun [p=.018] and action-verb [p=.026] fluency) relative deficits, but not attention/working memory, receptive or expressive language, nonverbal reasoning, or manual coordination/dexterity deficit. CONCLUSIONS Late-preterm birth is likely to be associated with negative neuropsychological sequelae, although subtle and selective compared to effects reported for children born at an earlier gestational age. Visuospatial function appears to be especially vulnerable to disruption even at preschool age, and verbal fluency may be useful as an early predictor of executive dysfunction in childhood. Routine preschool neuropsychological evaluation is recommended to identify delay or deficit in LPT children preparing for school entry, and may highlight underlying vulnerable neural networks in LPT children.

Cognitive deficit in preschoolers born late-preterm

BACKGROUND late-preterm (LPT) birth accounts for a majority of preterm deliveries and until recently was considered low risk for poor cognitive outcome. Previously, we reported deficits in complicated LPT (cLPT) preschoolers (neonatal intensive care unit [NICU]-admitted). AIM to extend our prior study by comparing cognitive outcome in cLPT and uncomplicated LPT (uLPT; NICU non-admitted) preschoolers. STUDY DESIGN single center retrospective cohort study of 118 LPT children born in 2004-2006 at 35-36 weeks of gestation; 90 cLPT and 28 uLPT, compared with 100 term-born (≥ 37 weeks of gestation and ≥ 2500 g) participants. OUTCOME MEASURE a well-standardized measure of general conceptual ability (GCA), the Differential Ability Scales, Second Edition. RESULTS cLPT participants had average mean performances but significantly poorer GCA, Nonverbal Reasoning, and Spatial scores than term-born children, and higher rates of Nonverbal Reasoning and Spatial impairment; uLPT did not differ from TERM. Combined LPT males were at eightfold greater risk than term-born males for nonverbal deficit, and at sevenfold greater risk for GCA impairment than LPT females. CONCLUSIONS finding greater risk of cognitive deficit in those NICU-admitted due to clinical instability or birth weight < 2 kg compared with non-admitted preschoolers indicates that neonatal morbidities contribute to subtle cognitive deficits detectable at young age, with male gender an additive risk factor. LPT gestational age alone is an insufficient predictor of long-term neurocognitive outcome. Further study should elucidate salient etiologies for early emerging cognitive weaknesses and suggest appropriate interventions to prepare at-risk LPT preschoolers for elementary school entry.

Extremely preterm birth outcome: a review of four decades of cognitive research.

Premature birth incidence and survival rates are increasing steadily due to advances in obstetric and neonatal intensive care. Those born at the limits of viability are highly at-risk of adverse neurocognitive function over their lifespan, leading to current controversy regarding aggressive resuscitation efforts for these extremely preterm children. However, data from earlier generation cohorts who were born in substantially different eras of neonatal intensive care cannot be relied on to predict outcome of today’s newborn. Our review by the crucial variable of birth cohort year shows a changing developmental trajectory in which today’s extremely preterm survivor is likely to have fewer severe medical complications, better neurological outcomes, and fewer adverse cognitive late effects. Such data further underscore the importance of concurrently considering medical, familial, socioenvironmental, and neurobiological factors in combination with individual neonatal intensive care center protocols when studying outcomes of the preterm child. This complex, interrelated range of factors directly affects the immature, rapidly developing premature brain. However, ongoing surveillance to detect subsequent delay or impairment and to apply interventional strategies early in the developmental course holds promise for further enhancement of functional outcome.

Executive functions in extremely low birth weight and late-preterm preschoolers: Effects on working memory and response inhibition

Executive function (EF) refers to fundamental capacities that underlie more complex cognition and have ecological relevance across the individuals lifespan. However, emerging executive functions have rarely been studied in young preterm children (age 3) whose critical final stages of fetal development are interrupted by their early birth. We administered four novel touch-screen computerized measures of working memory and inhibition to 369 participants born between 2004 and 2006 (52 Extremely Low Birth Weight [ELBW]; 196 late preterm; 121 term-born). ELBW performed worse than term-born on simple and complex working memory and inhibition tasks and had the highest percentage of incomplete performance on a continuous performance test. The latter finding indicates developmental immaturity and the ELBW groups most at-risk preterm status. Additionally, late-preterm participants performed worse compared with term-born on measures of complex working memory but did not differ from those term-born on response inhibition measures. These results are consistent with a recent literature that identifies often subtle but detectable neurocognitive deficits in late-preterm children. Our results support the development and standardization of computerized touch-screen measures to assess EF subcomponent abilities during the formative preschool period. Such measures may be useful to monitor the developmental trajectory of critical executive function abilities in preterm children, and their use is necessary for timely recognition of deficit and application of appropriate interventional strategies.

Late preterm birth: a review of medical and neuropsychological childhood outcomes.

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks’ gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth’s disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.

Neuropsychological functioning in early hydrocephalus: review from a developmental perspective.

Children with hydrocephalus have deficits in several neuropsychological domains. The most notable are motor, visuoperceptual, and visuomotor function. These deficits are multiply determined and depend on the etiology and severity of the hydrocephalus to a large extent. Corpus callosum abnormalities resulting from stretching of callosal fibers and other cortical white matter tracts are implicated as contributory to these deficits. Enlarged ventricles and associated compression of posterior cortical areas also correlate with cognitive impairment. Distinguishing which cognitive domain negatively impacts on the child’s functioning and which domains influence behavior in isolation or in combination has been the subject of numerous studies. Developmentally, we know little about the emergence of neuropsychological functioning in children with hydrocephalus. Study of the effects of hydrocephalus at different stages of development is useful to clinicians and researchers interested in the impact of diffuse neurophysiological damage on cognition in the developing brain. The medical and neuropsychological literature have begun to inform about these effects. The core deficits in hydrocephalus have yet to be explicated and a focus on investigations that answer these questions is required. This review summarizes the current knowledge about neurocognitive sequelae of hydrocephalus.

Neuropsychological and behavioral outcomes of extremely low birth weight at age three.

Preterm (PT) birth is an established risk factor for high mortality and morbidity rates. Infants and school-aged children have been well-studied, but few have described neuropsychological and behavioral outcomes at preschool age. We compared a 2004–2006 preterm/extremely low birth weight (ELBW) cohort (PT/ELBW; N = 60) born ≤33 weeks gestation and <1,000 g with term-born participants (N = 90) at age 3. PT/ELBW subgroups (<26 weeks; 26–33 weeks) performed more poorly than the term-born group on verbal, nonverbal, fine motor, visual-motor, visual attention, noun fluency, early number concepts, and functional communication measures prior to age correction; PT/ELBW children born <26 weeks additionally performed more poorly on action-verb fluency. Those born 26–33 weeks had executive and adaptive deficits on parental behavioral report. Age correction significantly improved preterm scores without masking relative verbal, nonverbal, motor, and behavioral weaknesses that may require early intervention. In conclusion, subtle delays in emergent neuropsychological and behavioral functions are measurable at age 3, and neurobiological immaturity remains a prepotent influence on outcome in the preschool years. Further study should enhance our understanding of the trajectory of brain development and the limits of neuroplasticity in these highly at-risk children.

Age-appropriate early school age neurobehavioral outcomes of extremely preterm birth without severe intraventricular hemorrhage: A single center experience

BACKGROUND Extremely low birth weight (ELBW) is an established risk factor for poor neurocognitive outcome, particularly when severe intraventricular hemorrhage (IVH) complicates the neonatal course. Those born <26 weeks gestational age (GA) are at greatest risk, their outcomes poorer than later born ELBW children. Outcomes of GA subgroups of ELBW uncomplicated by severe IVH have not been well described. AIM To compare neurocognitive and behavioral outcomes of those born < and >or=26 weeks for an ELBW cohort treated in a single center with extremely low IVH incidence. DESIGN Single center retrospective observational cohort study of <or=1000 g survivors born between 1998-2000, using standardized tests of cognition, academic achievement, executive function, attention, language, memory, motor/visual-motor skill, parent and teacher behavioral questionnaires. RESULTS ELBW participants (mean age: 6.85+/-0.79) had a mean General Cognitive Ability of 101.4+/-13.05; no significant differences found between <26 weeks (98.19+/-12.48) and >or=26 weeks (102.97+/-13.21) subgroups. No neurocognitive, achievement, or behavioral score was impaired (>or=2 SDs below the normative mean). Subgroup comparisons were nonsignificant after controlling for BW and maternal education, except for >or=26 week advantage for phoneme analysis. Poorer, but low average, performances were found for motor dexterity/coordination, spatial working memory, and selective attention. CONCLUSIONS Age-appropriate neurocognitive and behavioral function of ELBW survivors suggests outcome may be predicted based on IVH incidence as opposed to birth weight or GA. Factors leading to decreased IVH incidence deserve further study, via single- and cross-center methodologies, to enhance decision-making regarding resuscitation and care of these highly at-risk neonates.