The impact of lesion size on executive function performance in children and adolescents after pediatric stroke

Abstract

Cognitive deficits after childhood arterial ischemic stroke (AIS) can be observed in more than half the affected children, especially in executive functions. Previous research revealed some main factors that influence cognitive outcome after childhood AIS, including lesion location, lesion size, and age at stroke. However, the importance of lesion size particularly has been discussed controversially. Thus, the present study takes a closer look at the impact of lesion size on executive performance in children who suffered an AIS using both direct cognitive testing and parental ratings. The study sample comprised 14 patients after childhood AIS (mean age 12.71, 5 female) and 14 age- and sex-matched healthy controls (mean age 11.00, 6 female). Results of cognitive testing revealed that the patient group performed poorer in executive functioning compared to controls, but mostly within the normal range. Lesion size correlated with sustained attention performance and some of the parental rating scales. However, if these correlations were controlled for sustained attention, lesion size was no longer correlated with any parental rating scale. The results of the present study suggest that sustained attention performance mediates the correlation between parental ratings of executive functions and lesion size. This confounding factor may explain inconsistent results of the relationship between lesion size and cognitive outcome in previous research.