Movement preparation and execution: differential functional activation patterns after traumatic brain injury

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Motor Control

Background:

• Traumatic brain injury (TBI) frequently leads to persistent motor control deficits, particularly in bimanual coordination.
• Previous research linked these deficits to structural abnormalities in white and grey matter.
• Functional brain activation patterns during motor tasks in TBI patients remain underexplored.

Purpose of the Study:

• To investigate cerebral functional activation patterns during bimanual movement preparation and execution in patients with TBI.
• To compare these patterns with those of healthy controls using functional magnetic resonance imaging (fMRI).

Main Methods:

• Eighteen moderate-to-severe TBI patients and 26 healthy controls performed a complex bimanual tracking task.
• The task included preparation and execution phases, with and without augmented visual feedback.
• fMRI was used to measure brain activity during task performance.

Main Results:

• TBI patients showed impaired bimanual tracking performance compared to controls, with worse performance without visual feedback.
• During preparation, TBI patients exhibited reduced activation in frontal, parietal, and occipital areas.
• During execution, TBI patients showed enhanced activation in frontal, parietal, occipital, and subcortical areas, with decreased neural differentiation between feedback conditions.

Conclusions:

• TBI patients demonstrate poorer predictive control during bimanual tasks.
• Overactivation during movement execution in TBI patients suggests more controlled, possibly compensatory, processing.
• Findings highlight altered functional brain dynamics underlying motor deficits after TBI.