Resting‐State Power and Regional Connectivity After Pediatric Mild Traumatic Brain Injury

Abstract

Background: Physiological recovery from pediatric mild traumatic brain injury (pmTBI) as a function of age remains actively debated, with the majority of studies relying on subjective symptom report rather than objective markers of brain physiology. Purpose: To examine potential abnormalities in fractional amplitude of low-frequency fluctuations (fALFF) or regional homogeniety (ReHo) during resting-state fMRI following pmTBI. Study Type: Prospective cohort. Population: Consecutively recruited pmTBI (N = 105; 8-18 years old) and age-and sex-matched healthy controls (HC; N = 113). Field Strength/Sequence: 3T multiecho gradient T 1-weighted and single-shot gradient-echo echo-planar imaging. Assessment: All pmTBI participants were assessed 1 week and 4 months postinjury (HC assessed at equivalent timepoints after the first visit). Comprehensive demographic, clinical, and cognitive batteries were performed in addition to primary investigation of fALFF and ReHo. All pmTBI were classified as "persistent" or "recovered" based on both assessment periods. Statistical Tests: Chi-square, nonparametric, and generalized linear models for demographic data. Generalized estimating equations for clinical and cognitive data. Voxelwise general linear models (AFNI's 3dMVM) for fALFF and ReHo assessment. Results: Evidence of recovery was observed for some, but not all, clinical and cognitive measures at 4 months postinjury. fALFF was increased in the left striatum for pmTBI relative to HC both at 1 week and 4 months postinjury; whereas no significant group differences (P > 0.001) were observed for ReHo. Age-at-injury did not moderate either resting-state metric across groups. In contrast to analyses of pmTBI as a whole, there were no significant (P > 0.001) differences in either fALFF or ReHo in patients with persistent postconcussive symptoms compared to recovered patients and controls at 4 months postinjury. Data Conclusions: Our findings suggest prolonged clinical recovery and alterations in the relative amplitude of restingstate fluctuations up to 4 months postinjury, but no clear relationship with age-at-injury or subjective symptom report. Level of Evidence: 1 Technical Efficacy: 2

White matter microstructure of the neural emotion regulation circuitry in mild traumatic brain injury

“…Although highly speculative, it is tantalizing to elaborate on a possible protective effect of compromised UF microstructure regarding the development of persistent symptoms via the presence of less emotional awareness. In line with our results, previous diffusion and resting‐state fMRI studies have shown null findings with respect to persistent symptoms in pediatric and adult mTBI (Ilvesmaki et al., 2016; Stephenson et al., 2020; Wäljas et al., 2014). Other studies have reported diffusion abnormalities in the same tracts that were examined in our study, and that these abnormalities were related to PTS (Aoki & Inokuchi, 2016; Dodd et al., 2014; Hellstrøm et al., 2017; King et al., 2019; Mayer et al., 2010; Wallace et al., 2020).…”

Resting-State Functional MRI Metrics in Patients With Chronic Mild Traumatic Brain Injury and Their Association With Clinical Cognitive Performance

“…fALFF is also associated with increased metabolism in cortical regions. Higher fALFF and metabolism in cortical areas could be interpreted as representing a potential compensatory response to the damage in patients suffering from trauma ( Stephenson et al, 2020 ). In line with this, a recent study in patients with severe TBI showed higher ALFF in the right temporal, frontal, and IPC in the conscious subgroup compared with the coma subgroup.…”

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

“…In this study, rs-fMRI was used to provide insight into areas of the brain that are synchronously active at rest in the absence of any particular cognitive stimuli) to explore the functional neuropathology of concussion. While the brain regions and/or networks studied, time of imaging, and rs-fMRI analysis methods themselves have varied across studies, studies consistently show that there are rs-fMRI disturbances in children with concussion in comparison to their healthy peers 12-23 . Collectively, these studies have shown patterns of both hyper-and hypo-connectivity within the initial weeks of injury 24 , abnormal rs-fMRI activity in children with protracted symptoms 15 , and a persistence of functional impairment in asymptomatic children who have been medically cleared to return-to-sport 21 .…”