White Matter Connectivity and Executive Function in Young Children with ADHD

Overview

Attention-deficit hyperactivity disorder (ADHD) is a common childhood neurodevelopmental disorder marked by inattention, hyperactivity, and impulsiveness. The importance of the Superior Longitudinal Fasciculus II (SLFII), a white matter tract connecting the frontal and parietal regions, to developing executive function has not been established in children who typically have executive function deficits. The present study explored the association between diffusion properties of the SLFII and developing executive function in young children diagnosed with ADHD. The performance on the NIH Toolbox Card Sort and the NIH Toolbox Flanker, two executive function tasks, in 59 4-7-year-old children was assessed. Diffusion-weighted magnetic resonance imaging scans were used to quantify the white matter properties of the bilateral SLFII. The results showed that there was an association between age and performance on the Flanker and Card Sort tasks. As age increased, performance also improved. There was no significant association between white matter properties of the SLFII, birth sex, and the Card Sort and Flanker tasks. As the first study to explore this association in children of this age with ADHD, this result was unexpected suggesting that it may be the case that it is too early in development to detect a strong association. The findings inform contemporary and future investigations into the brain-behavior relations between SLFII and executive function in children with ADHD. With further research, neuroimaging could become a potential diagnostic biomarker for predicting executive function impairments and ADHD symptoms in young children, potentially altering treatment outcomes.