Neuropsychology is interested in how our brain and other parts of the nervous system influence aspects of our cognitive, emotional and behavioural functioning. Understanding the neuropsychological functioning of school-age children with agenesis of the corpus callosum (ACC) means knowing about their general intellectual and cognitive abilities, as well as their academic, social, emotional and behavioural functioning. Such knowledge can be helpful for families, practitioners and teachers to understand how we might expect a child with ACC to function in daily life, including areas of difficulty and strength that a child might experience. This knowledge can also be helpful for understanding the types of early interventions that might be beneficial in supporting positive development in children with ACC, and the types of school support that might be beneficial.

To have a good understanding of the neuropsychological functioning of children with ACC researchers need to study large samples of children. So far most studies have been based on small samples or studies have focused on adults. As part of the Paediatric Agenesis of the Corpus Callosum Project at the Murdoch Children’s Research Institute in Melbourne, we have described neuropsychological functioning in a relatively large cohort of school-age children with ACC (either partial ACC or complete ACC) who presented for clinical services to a hospital. An important finding of this study is that there is a wide range in the neuropsychological functioning of children diagnosed with ACC who present for clinical attention. Around half of our cohort experienced general intellectual, academic, executive, social and/or behavioural difficulties, while around 20% of our cohort were functioning at a level similar to their typically developing peers. We also found that children tended to show relative strengths within some neuropsychological domains: for intellectual abilities they generally showed stronger non-verbal than verbal abilities, for academic performance they showed stronger spelling and reading than mathematics, and for executive functioning children showed better behavioural regulation than meta-cognition (insight into their own thinking).

Together, these findings suggest that there is no clear and unique neuropsychological profile for children with ACC. Perhaps this is not surprising given the wide range in the presentation of ACC, for example, presenting with partial or complete ACC, some have a genetic syndrome and others do not have an identified genetic syndrome, and some experience a seizure disorder while others do not.

A key question is why some children with ACC experience neuropsychological difficulties and others function at a level similar to their typically developing peers. We want to identify early the children at risk for neuropsychological difficulties who might benefit from interventions. To do this we are studying a range of factors that might influence neuropsychological development in children with ACC. We know that many factors can influence child development, including social, environmental, genetic and neurological factors. Research suggests that the story is complicated and it is likely that many factors influence neuropsychological functioning in children with ACC. So far studies of our cohort have found that some neurological factors such as having brain anomalies, complete ACC, and microstructure of the anterior commissure (a small pathway connecting the brain’s hemispheres) are associated with difficulties in some (but not all) aspects of neuropsychological functioning. Social risk (social and economic disadvantage) seems to be particularly important for understanding the wide range in neuropsychological functioning observed in children with ACC. These initial findings suggest that providing children with ACC and their families with a supportive social environment could promote positive neuropsychological functioning across a range of domains, for example through school support and aid, parenting advice, and access to tailored interventions according to the child’s individual difficulties.

More research is needed in large cohorts of children with ACC to better understand neuropsychological functioning in school-age children, and help identify early the children with ACC at risk of neuropsychological difficulties who might benefit from intervention.

Megan Spencer-Smith