Effect of behavioural practice targeted at the motor action selection network after stroke

• Published in: The European journal of neuroscience 2022-08, Vol.56 (4), p.4469-4485
• Main Authors: Stewart, Jill Campbell, Baird, Jessica F., Lewis, Allison F., Fritz, Stacy L., Fridriksson, Julius
• Format: Article
• Language: English
• Subjects: action selection; brain imaging; Cortex (parietal); motor planning; Prefrontal cortex; Reaction time task; Rehabilitation; Somatosensory cortex; Stroke; upper extremity
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.15754

Motor action selection engages a network of frontal and parietal brain regions. After stroke, individuals activate a similar network, however, activation is higher, especially in the contralesional hemisphere. The current study examined the effect of practice on action selection performance and brain activation after stroke. Sixteen individuals with chronic stroke (Upper Extremity Fugl–Meyer motor score range: 18–61) moved a joystick with the more‐impaired hand in two conditions: Select (externally cued choice; move right or left based on an rule) and Execute (simple response; move same direction every trial). On Day 1, reaction time (RT) was longer in Select compared to Execute, which corresponded to increased activation primarily in regions in the contralesional action selection network including dorsal premotor, supplementary motor, anterior cingulate and parietal cortices. After 4 days of practice, behavioural performance improved (decreased RT), and only contralesional parietal cortex significantly increased during Select. Higher brain activation on Day 1 in the bilateral action selection network, dorsolateral prefrontal cortex and contralesional sensory cortex predicted better performance on Day 4. Overall, practice led to improved action selection performance and reduced brain activation. Systematic changes in practice conditions may allow the targeting of specific components of the motor network during rehabilitation after stroke. After 4 days of practice, individuals post‐stroke improved action selection behavioural performance with a corresponding decrease in brain activation throughout the action selection network, especially in the contralesional hemisphere. Higher brain activation at baseline in the bilateral action selection network as well as prefrontal and sensory cortices predicted better performance on Day 4. Systematic changes in practice conditions may allow the targeting of specific components of the motor network during rehabilitation after stroke.