Evaluation of changes in motor and visual functional activation over time following moderate-to-severe brain injury

Primary objective: Relatively little research has documented functional recovery following traumatic brain injury using neuroimaging techniques. This study aimed to examine the effects of moderate-to-severe brain injury on brain functioning over time. Research design: Eight brain-injured participants completed motor and visual tasks during fMRI at two time points within the first year following injury. Changes in functional activation within ROIs and in dispersion of activation were evaluated across time points. Main outcomes and results: Participants demonstrated significantly reduced activation intensity within the ROI over time for the motor task, but not the RPS task. Participants demonstrated a (non-significant) trend toward reduced functional dispersion over time. Most participants demonstrated greater activation within (vs outside) the ROI for both tasks. Variability among participants, in terms of activation intensity and dispersion, was evident. Conclusions: The findings provide support for the occurrence of functional recovery over the first year post-injury, with fewer resources utilized during task completion over time. Additionally, results suggest that variability in functional activation and activation in brain regions typically activated among controls could be anticipated in a moderate-severe TBI group. Lastly, simple motor and visual tasks may be useful in efforts to demonstrate functional recovery over time.