Description (from grant):    

About 400,000 youth experience pediatric mild traumatic brain injury (pmTBI) each year. Neurobehavioral symptoms (i.e., cognitive, emotional, and somatic) of pmTBI are more pronounced in the first few weeks of injury, but it is not known how long these symptoms should typically last. Standard neuroimaging techniques are not very sensitive to the diffuse injuries that occur following pmTBI and we do not understand why these symptoms occur or why certain children recover whereas others do not. Children who remain symptomatic are faced with impairment in academic, interpersonal and social functioning, ultimately resulting in a reduced quality of life. A growing literature also suggests that repetitive traumatic events may result in long-term neuropsychiatric disturbances. Thus, developing biomarkers that are capable of tracking neurological change from the semi-acute to more chronic injury phases is a major public health objective. The current application will utilize state-of-the-art neuroimaging techniques (multi-shell DTI, rsfMRI and attention fMRI, CBF and CVR) to quantify how diffuse injuries (e.g., gray matter, white matter and vascular) change during the dynamic course of pmTBI, and how they relate to neurobehavioral symptoms. This information is of vital significance for clinical decisions about injury severity and return to normal physical activity, as well as for ultimately developing treatments that target injury mechanisms rather than symptomatology. We will collect longitudinal (1 week, 4 months and 1 year post-injury) neuroimaging and clinical data on a large cohort of pmTBI patients (N = 150) and healthy controls (N = 125), with the aim to better elucidate neuropathology underlying the expression of post-concussive symptoms (PCS) and the impact on clinical outcomes. One measurement of neurovascular function is cerebral vascular reactivity (CVR), which will allow us to disambiguate hemodynamic from neuronal dysfunction.