Poster #17 - Impact of earlier versus later interruption of typical brain maturation on executive functions

• In Event: 3-206 - Poster Session 13
  In Poster Session: PS 13 Section - Biological Processes: Neuroscience and Genetics

Integrative Statement

Executive functions (EFs) are higher-order cognitive processes that are essential for self-control or self-regulation ability (Miyake et al., 2000). Besides the typical neurodevelopment, EFs have been widely studied in patients with developmental brain alterations. It is assumed that cognitive and neural maturation in atypical neurodevelopment undergo different trajectories and involve impairments in aspects of EFs. Atypical neurodevelopment in the absence of brain lesions can occur in children born very preterm. These children have a pre- or perinatal onset of atypical neurodevelopment. Findings with very preterm born children reveal deviant brain development and an increased risk for academic and behavioral difficulties (Cheong et al., 2013). Atypical neurodevelopment also occurs in children after an arterial ischemic stroke (AIS). These children represent a childhood onset of atypical neurodevelopment and have an increased vulnerability for cognitive and behavioral difficulties (Hajek et al., 2013).

The current study examined the impact of an interruption of typical brain maturation on EFs in two different clinical groups. Group comparison within the clinical groups were run regarding earlier interruption versus later interruption of development.

The first group comprised 32 very preterm born children (<32 weeks gestational age and/or at very low birth weight < 1500 g, without MRI lesions in the neonatal phase). The second group consisted of 19 children and adolescents with chronic arterial AIS (time of the lesion > 2 years; age < 16 years at the time of AIS). Both clinical groups were divided into two groups (earlier vs. later interruption): Preterm-born children: < 28 weeks gestational-age (GA) versus > 28 weeks GA; AIS: < 7 years at stroke versus > 7 years at stroke. EFs were assessed between the ages of 8 - 22 by using standard neuropsychological tests focusing on inhibition (Color-Word Interference Test CWIT; D-KEFS), working memory (Letter-Number Sequencing; WISC-IV, WAIS) and shifting (Trail-Making Test, TMT and CWIT; D-KEFS). Additionally, processing speed was measured (processing speed index, WISC-IV/WAIS).

Preliminary analyses reveal that preterm-born children with an earlier interruption showed significantly lower performance in inhibition and shifting than preterm-born children with a later interruption. Contrary to this, performance on working memory was slightly but not significant better in preterm-born children with earlier interruption. Children and adolescents after AIS showed weaker group differences between earlier and later interruption. Tendencies for worse performance in case of earlier interruption were shown on inhibition and shifting whereas better but not significant performance on working memory occurred also after earlier interruption. In both clinical groups, there were strong positive relations (r = > .30, p < 0.01) between processing speed and the two EFs (inhibition, shifting). Overall, findings give interesting insights into earlier and later interruption of brain maturation in two different clinical groups. The results reveal similarities and differences of EFs across two different timepoints of onset in relation to the interruption. However, findings are discussed with respect to processing speed as an important participating cognitive factor, specifically for inhibition and shifting.

Authors

• Qendresa Thaqi, University of Bern
  Presenting Author

• Maja Steinlin, Division of Neuropediatrics, Development and Rehabilitation Children’s University Hospital, University of Bern
  Non-Presenting Author

• Claudia Roebers, Bern University
  Non-Presenting Author

• Regula Everts, Division of Neuropediatrics, Development and Rehabilitation Children’s University Hospital, University of Bern
  Non-Presenting Author