{'fraction_non_alphanumeric': 0.019413092550790066, 'fraction_numerical': 0.002708803611738149, 'mean_word_length': 5.806451612903226, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Neurodevelopmental outcomes in children with congenital heart disease: the role of perioperative neuroimaging

For professionals and parents caring for children with congenital heart disease (CHD), the long-term neurodevelopmental problems faced by these children are of utmost importance. Since the first paper from the Boston Circulatory Trial was published in the mid-1990s, the wealth of literature on neurodevelopmental outcomes has irrefutably established that children with CHD need structured, longitudinal followup. As cumulative understanding of the complex brain maturational processes and cerebrovascular physiology evolves the relationship between abnormal neuroimaging and later neurodevelopmental outcome needs to be clarified. An important knowledge gap exists between structural abnormalities identified in the critically ill neonates with CHD and their impact on later functional outcomes. Claessens et al. have attempted to address this gap in their study of 34 neonates with critical CHD. They have presented a comprehensive study on preand post operative neuroimaging (brain volumes, white matter injury [WMI], and grey matter focal infarctions) followed by 2-year (Bayley Scales of Infant and Toddler Development) and 6-year neurodevelopmental outcome (Movement Assessment Battery for Children, Wechsler Preschool and Primary Scale of Intelligence, and Child Behaviour Checklist and Teacher Report Form). This was achieved notwithstanding the logistical challenges in recruiting neonates to neuroimaging and sequential neurodevelopmental testing without significant attrition. They report that after adjusting for maternal education, the 2-year cognitive score and 6-year Full-scale IQ were significantly lower in children with neonatal WMI. The high incidence of WMI may be affected by the imaging protocols/techniques, the timing of imaging, the definition itself, and patient selection; thus, it may influence the results and conclusions in the context of a small study cohort. Despite this, the impact on neurodevelopmental outcome to the age of 6 years remains an important finding. The results are even more relevant as this cohort was comprised of few children with single ventricular physiology (who are known to have later poor neurodevelopmental outcome). Several researchers have reported on the increased incidence of new postoperative WMI and its associations with the diagnostic group, duration of cardiopulmonary bypass, and brain immaturity; while others have found no patientor procedure-related factors and reported new WMI in infants with and without bypass surgery. Brain immaturity (and not injury) has been reported to correlate with 2-year neurodevelopmental outcome. Claessens et al. further describe associations between the internal capsule posterior limb involvement and later motor function, and smaller volumes of basal ganglia-thalami/brainstem and below-average Full-scale IQ. Understanding the neuropathological substrate correlation with later neurodevelopment is noteworthy, bearing in mind that there may be complex mechanisms (such as abnormal brain microstructure and decreased connectivity) yet to be elucidated. Brain morphometric measurements (global and/or regional volumes) have been shown to be reduced in adolescents with CHD, as well as in survivors of critical illness in the neonatal period with important implications on functional outcomes. Adverse neurodevelopmental outcome is multifactorial in origin and it is important to focus on modifiable factors, right from the antenatal period, which is an area of current research. Early identification and timely interventions may influence the neurodevelopmental profile and testing results of any study cohort, when longitudinally assessed. Future studies should assess the impact of such interventions and include parental perspectives, which add a valuable dimension to the spectrum of neurodevelopmental issues. Claessens et al. have presented a much-needed study clarifying the role of neuropathological correlates on neuroimaging and long-term follow-up in children undergoing complex cardiac surgery. This study will add to the repository of information available on lifelong functional abilities and outcome of children undergoing complex cardiac surgery. It reinforces the need for continuing structured surveillance and interventions to optimize neurodevelopmental health of neonates with critical CHD.