Abstract
Adolescents who have sustained a concussion or mild traumatic brain injury (mTBI) are prone to repeat injuries which may be related to subtle motor deficits persisting after clinical recovery. Cross-sectional research has found that these deficits are associated with altered functional connectivity among somatomotor, dorsal attention, and default mode networks. However, our understanding of how these brain-behavior relationships change over time after clinical recovery is limited. In this study, we examined categorical and dimensional trajectories of functional connectivity and subtle motor performance in youth clinically recovered from mTBI and never-injured controls (10-17 years). All participants completed task-based and resting-state functional magnetic resonance imaging scans and the Physical and Neurological Examination of Subtle Signs (PANESS) at initial and 3-month follow-up visits. We examined somatomotor-dorsal attention and somatomotor-default mode network connectivity and their association with PANESS performance. Compared with controls, a larger proportion of youth recovered from mTBI showed increases in somatomotor-dorsal attention functional connectivity over time; in contrast, there were no differences in somatomotor-default mode connectivity trajectories between youth recovered from mTBI and controls. Relative to controls, youth recovered from mTBI who showed greater increases in somatomotor-dorsal attention connectivity over time also completed motor tasks more slowly at the 3-month compared with the initial visit. Collectively, these findings suggest that longitudinal changes in somatomotor-dorsal attention functional connectivity may be associated with lingering motor learning deficits after clinical recovery from pediatric mTBI. Further research is necessary to understand how trajectories of functional connectivity and motor performance can inform individual-level outcomes, for instance, susceptibility to future injuries in both youth who are never injured and those clinically recovered from mTBI.