Exploring the relationship between resting-state intra-network connectivity and accelerometer-measured physical activity in pediatric concussion: a cohort study

Our objective was to explore the association between resting-state functional connectivity and accelerometer-measured physical activity in pediatric concussion. Fourteen children with concussion (aged 14.54 ± 2.39 years, 8 female) were included in this secondary data analysis of a larger study. Participants had neuroimaging at 15.3 ± 6.7 days postinjury and subsequently a mean of 11.1 ± 5.0 days of accelerometer data. Intra-network connectivity of the default mode network (DMN), sensorimotor network (SMN), salience network (SN), and frontoparietal network (FPN) was computed using resting-state MRI. We found that, per general linear models (GLMs), only intra-network connectivity of the DMN was associated with physical activity levels. More specifically, increased intra-network connectivity of the DMN was significantly associated with higher levels of subsequent accelerometer-measured light physical activity (LPA; F_{(2, 11)} = 7.053, p = 0.011, R_a² = 0.562; β = 0.469), moderate physical activity (MPA; F_{(2, 11)} = 6.159, p = 0.016, Ra2 = 0.528; β = 0.725), and vigorous physical activity (VPA; F_{(2, 11)} = 10.855, p = 0.002, R_a² = 0.664; β = 0.792). Intra-network connectivity of the DMN did not significantly predict sedentary time. Therefore, these preliminary findings suggest that there is a positive association between the intra-network connectivity of the DMN and device-measured physical activity in children with concussion.