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Job Title
Research Assistant, Neurology
Academic Rank
Staff/Research Assistant
Department
Neurology
Authors
Hui Shi, Yelena G. Bodien, Karl Zimmerman, David Sharp, Michael D. Fox, Brian L. Edlow, Samuel B. Snider
Principal Investigator
Samuel B. Snider
Categories
Tags
After traumatic brain injuries (TBIs), many patients remain with severe disability due to cognitive impairment. It is not currently possible to predict individuals’ recoveries. Resting state functional MRI (rs-fMRI) now enables the measurement of functional integrity of distributed brain networks and the “toggling” of activity between the task-positive (Salience) and task-negative (Default Mode) networks (DMN), which are both associated with normal cognition. Thus, we sought to test whether rs-fMRI-measured network integrity predicts functional outcomes after TBI.
We combined three datasets to form a sample of 101 patients with moderate/severe TBI and 207 matching healthy controls. For all participants, we obtained an MRI within 2 months of injury. The primary outcome was Glasgow Outcome Scale -Extended (GOSE) < 5 at 6-months post injury, indicating severe disability. We segmented the brains into 7 resting state networks, each represented by 3-4 regions of interest. We screened all region-to-region connections using univariate logistic regressions, performing bidirectional stepwise selection on FDR-significant variables. When controlling for prognostic markers, only the Salience-DMN inter-network connectivity was associated with unfavorable outcome (aOR, 1.5, p< 0.05). These findings suggest that “toggle-switch” preservation may be a critical marker of brain health with implications for improved disability prediction and neuromodulatory treatment targets.
After traumatic brain injuries (TBIs), many patients remain with severe disability due to cognitive impairment. It is not currently possible to predict individuals’ recoveries. Resting state functional MRI (rs-fMRI) now enables the measurement of brain region connectivity and communication and the “toggling” of activity between the task-positive (Salience) and task-negative (Default Mode) networks (DMN), which are both associated with normal function. Thus, we sought to test whether rs-fMRI-measured network functionality predicts functional outcomes after TBI.
We combined three datasets to form a sample of 101 patients with moderate/severe TBI and 207 matching healthy controls. For all participants, we obtained an MRI within 2 months of injury. The primary outcome was Glasgow Outcome Scale -Extended (GOSE) < 5 at 6-months post injury, indicating severe disability. We split the brains into 7 networks, each represented by 3-4 regions of interest. We took the region-to-region connectivity with the strongest relationship to outcome and determined the effect of clinical variables on these region-outcome connections. When controlling for GOSE outcomes, only the Salience-DMN inter-network connectivity was associated with unfavorable outcome. These findings suggest that “toggle-switch” preservation may be a critical marker of brain health with implications for improved disability prediction and treatment targets.
