NEUROCOGNITIVE SEQUELAE OF REPAIRED CONGENITAL HEART DISEASE (CHD)

Abstract

Purpose/Hypothesis: Children with cyanotic CHDs are at risk for neurological damage due to lack of oxygen supply to the brain early in post-natal development. Global delays/deficits in cognitive development, measured by intellectual assessment, have been reported. The neural basis of these cognitive impairments remains unclear. The purpose of this research was to characterize cognitive development in children with repaired CHD from a neuroscientific perspective and attempt to elucidate specific patterns of deficits. The hippocampus is a brain structure that subserves declarative memory. This structure is particularly vulnerable to oxygen deprivation, a common occurrence both prior to and as a result of surgical repair of cyanotic CHD. Therefore, we hypothesized that children with repaired cyanotic CHD would show deficits in declarative memory with relative sparing of other cognitive functions. Number of Subjects: Subjects were 7–11 year-old children with repaired cyanotic CHD (n = 12) and age-matched controls (n = 12). Materials/Methods: The Cambridge Neuropsychological Testing Automated Battery (CANTAB) and an intellectual assessment (WISC-III) were used to measure specific and global cognitive function, respectively. The CANTAB is a computerized battery of non-verbal, visually presented, cognitive tasks with specific neural correlates. Children also underwent a brief neurological exam by a physical therapist. Results: Global cognitive function of the CHD group was within normal ranges, though significantly impaired compared to matched controls (P < 0.05). These findings are largely consistent with previous reports. Specific neurocognitive testing revealed that performance of cyanotic CHD and control groups on specific cognitive tasks did not differ significantly. However, consistent trends suggest that children with repaired cyanotic CHD show subtle decrements in memory and executive functions. Multiple regressions will be performed to identify risk factors that predict variance in cognitive development. Conclusions: Children with cyanotic CHD demonstrate subtle global cognitive deficits. They may also demonstrate specific deficits in memory, both that subserved by the hippocampus and that thought to rely on frontal lobe areas. The extant literature suggests children with CHD often demonstrate gross and/or fine motor delays/deficits. Thus, our future studies of children with CHD aim to examine both cognitive and motor abilities to relate the development of these entwined neurological functions. Clinical Relevance: Recent advances in cardiac surgery have improved the survival of children with CHDs. Therefore, the identification and amelioration of neurodevelopmental morbidity has become increasingly important. PTs play an important role in the rehabilitation and care of children with CHD and are dedicated to maximizing their neurodevelopmental potential. When employing a dynamic systems approach, we realize that a better understanding of multiple domains of development, including movement and cognition, will improve our evaluation and treatment abilities and, ideally, translate to improved patient outcomes.