Aiko Lundequist

Visual‐motor and executive functions in children born preterm: The Bender Visual Motor Gestalt Test revisited

Visual-motor development and executive functions were investigated with the Bender Test at age 5½ years in 175 children born preterm and 125 full-term controls, within the longitudinal Stockholm Neonatal Project. Assessment also included WPPSI-R and NEPSY neuropsychological battery for ages 4-7 (Korkman, 1990). Bender protocols were scored according to Brannigan & Decker (2003), Koppitz (1963) and a complementary neuropsychological scoring system (ABC), aimed at executive functions and developed for this study. Bender results by all three scoring systems were strongly related to overall cognitive level (Performance IQ), in both groups. The preterm group displayed inferior visual-motor skills compared to controls also when controlling for IQ. The largest group differences were found on the ABC scoring, which shared unique variance with NEPSY tests of executive function. Multiple regression analyses showed that hyperactive behavior and inattention increased the risk for visual-motor deficits in children born preterm, whereas no added risk was seen among hyperactive term children. Gender differences favoring girls were strongest within the preterm group, presumably reflecting the specific vulnerability of preterm boys. The results indicate that preterm children develop a different neurobehavioral organization from children born at term, and that the Bender test with a neuropsychological scoring is a useful tool in developmental screening around school start.

Ability and Disability in Autism Spectrum Disorder: A Systematic Literature Review Employing the International Classification of Functioning, Disability and Health‐Children and Youth Version

Objective: This study is the first in a series of four empirical investigations to develop International Classification of Functioning, Disability and Health (ICF) Core Sets for Autism Spectrum Disorder (ASD). The objective was to use a systematic review approach to identify, number, and link functional ability and disability concepts used in the scientific ASD literature to the nomenclature of the ICF‐CY (Children and Youth version of the ICF, covering the life span). Methods: Systematic searches on outcome studies of ASD were carried out in Medline/PubMed, PsycINFO, ERIC and Cinahl, and relevant functional ability and disability concepts extracted from the included studies. These concepts were then linked to the ICF‐CY by two independent researchers using a standardized linking procedure. New concepts were extracted from the studies until saturation of identified ICF‐CY categories was reached. Results: Seventy‐one studies were included in the final analysis and 2475 meaningful concepts contained in these studies were linked to 146 ICF‐CY categories. Of these, 99 categories were considered most relevant to ASD (i.e., identified in at least 5% of the studies), of which 63 were related to Activities and Participation, 28 were related to Body functions, and 8 were related to Environmental factors. The five most frequently identified categories were basic interpersonal interactions (51%), emotional functions (49%), complex interpersonal interactions (48%), attention functions (44%), and mental functions of language (44%). Conclusion: The broad variety of ICF‐CY categories identified in this study reflects the heterogeneity of functional differences found in ASD—both with respect to disability and exceptionality—and underlines the potential value of the ICF‐CY as a framework to capture an individuals functioning in all dimensions of life. The current results in combination with three additional preparatory studies (expert survey, focus groups, and clinical study) will provide the scientific basis for defining the ICF Core Sets for ASD for multipurpose use in basic and applied research and every day clinical practice of ASD. Autism Res 2015, 8: 782–794.

Cognitive outcome varies in adolescents born preterm, depending on gestational age, intrauterine growth and neonatal complications

The aim of this study was to investigate long‐term cognitive outcome in a cohort of 18‐year‐olds born preterm and previously assessed at the age of 5.5.

Individual cognitive patterns and developmental trajectories after preterm birth

Cognitive outcome after preterm birth is heterogeneous, and group level analyses may disguise individual variability in development. Using a person-oriented approach, this study investigated individual cognitive patterns and developmental trajectories from preschool age to late adolescence. As part of a prospective longitudinal study, 118 adolescents born preterm, with a birth weight < 1,500 g, participated in neuropsychological assessments at age 5½ years and at 18 years. At each age, four cognitive indices, two tapping general ability and two tapping executive functions, were formed to reflect each individual’s cognitive profile. Cluster analyses were performed at each age separately, and individual movements between clusters across time were investigated. At both 5½ and 18 years, six distinct, and similar, cognitive patterns were identified. Executive functions were a weakness for some but not all subgroups, and verbal ability was a strength primarily among those whose overall performance fell within the normal range. Overall, cognitive ability at 5½ years was highly predictive of ability at age 18. Those who performed at low levels at 5½ years did not catch up but rather deteriorated in relative performance. Over half of the individuals who performed above the norm at 5½ years improved their relative performance by age 18. Among those performing around the norm at 5½ years, half improved their relative performance over time, whereas the other half faced increased problems, indicating a need for further developmental monitoring. Perinatal factors were not conclusively related to outcome, stressing the need for cognitive follow-up assessment of the preterm-born child before school entry.

Correlation between white matter microstructure and executive functions suggests early developmental influence on long fibre tracts in preterm born adolescents

Main objectives Executive functions are frequently a weakness in children born preterm. We examined associations of executive functions and general cognitive abilities with brain structure in preterm born adolescents who were born with appropriate weight for gestational age and who have no radiological signs of preterm brain injury on neuroimaging. Methods The Stockholm Neonatal Project (SNP) is a longitudinal, population-based study of children born preterm (<36 weeks of gestation) with very low birth weight (<1501g) between 1988–1993. At age 18 years (mean 18 years, SD 2 weeks) 134 preterm born and 94 full term participants underwent psychological assessment (general intelligence, executive function measures). Of these, 71 preterm and 63 full term participants underwent Magnetic Resonance Imaging (MRI) at mean 15.2 years (range 12–18 years), including 3D T1-weighted images for volumetric analyses and Diffusion Tensor Imaging (DTI) for assessment of white matter microstructure. Group comparisons of regional grey and white matter volumes and fractional anisotropy (FA, as a measure of white matter microstructure) and, within each group, correlation analyses of cognitive measures with MRI metrics were carried out. Results Significant differences in grey and white matter regional volumes and widespread differences in FA were seen between the two groups. No significant correlations were found between cognitive measures and brain volumes in any group after correction for multiple comparisons. However, there were significant correlations between FA in projection fibres and long association fibres, linking frontal, temporal, parietal, and occipital lobes, and measures of executive function and general cognitive abilities in the preterm born adolescents, but not in the term born adolescents. Overall significance of the study In persons born preterm, in the absence of perinatal brain injury on visual inspection of MRI, widespread alterations in regional brain tissue volumes and microstructure are present in adolescence/young adulthood. Importantly, these alterations in WM tracts are correlated with measures of executive function and general cognitive abilities. Our findings suggest that disturbance of neural pathways, rather than changes in regional brain volumes, are involved in the impaired cognitive functions.

Executive dysfunction in young adults born preterm : Neuropsychological test results and structural brain correlates

Preterm children appear to develop a different neurobehavioral organization from children born at term, and executive function (EF) has repeatedly been cited as an area of specific weakness. Likewise, neuroimaging studies have shown that the majority of very preterm infants display structural abnormalities, including white matter injury and volumetric differences (Nagy et al., 2003, 2009). Based on the analysis of the effects of lesion in adults, Stuss & Alexander (2007) have proposed a theoretical model, relating discrete categories of EF to regions within the frontal lobes. These EF categories and their coarse frontal localizations are: Executive cognition – dorsolateral prefrontal cortex (DLPFC), Behavioral / emotional self regulation – Ventral prefrontal cortex (VPFC) and Energization- superior medial frontal gyrus. The aim of this study was to identify preterm young adults’ strengths and weakness in terms of EF categories, and investigate their brain structural correlates. Preterm children appear to develop a different neurobehavioral organization from children born at term, and executive function (EF) has repeatedly been cited as an area of specific weakness. Likewise, neuroimaging studies have shown that the majority of very preterm infants display structural abnormalities, including white matter injury and volumetric differences (Nagy et al., 2003, 2009). Based on the analysis of the effects of lesion in adults, Stuss & Alexander (2007) have proposed a theoretical model, relating discrete categories of EF to regions within the frontal lobes. These EF categories and their coarse frontal localizations are: Executive cognition – dorsolateral prefrontal cortex (DLPFC), Behavioral / emotional self regulation – Ventral prefrontal cortex (VPFC) and Energization- superior medial frontal gyrus. The aim of this study was to identify preterm young adults’ strengths and weakness in terms of EF categories, and investigate their brain structural correlates. As a part of the longitudinal Stockholm Neonatal Project, 62 preterm and 38 term children were administered the Delis-Kaplan Executive Function System (D-KEFS) and behavioral self-reports (YSR and SDQ) as indices of EF at age 18. To investigate structural brain correlates, T1 and T2 weighted and diffusion weighted magnetic resonance images have been collected using a 1.5 T scanner. Results showed that preterm children had deficits primarily in Executive cognition and Energization, and less so in Behavioral self-regulation, with the extremely preterm children, born GA 23-28, having the most marked deficits also when controlling for overall cognitive level. Structural brain correlates are presently analyzed and preliminary findings are presented. Conclusion: A theory-based and interdisciplinary approach promotes our understanding of executive dysfunction in preterm children.