On the Use of Robotic Technology to Quantify Sensorimotor Impairments After Stroke

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Park, Kayne
neuroscience , stroke , robotics , motor control , upper limb
It is well recognized that sensory feedback plays an important role in allowing us to move and interact in our complex world. However, sensory feedback can be impaired following stroke potentially reducing an individual’s independence and increasing their fall risk. Commonly used clinical assessments do not have the ability to accurately quantify these impairments. The objective of this dissertation is to use robot-based behavioural tasks to accurately quantify impairments in the use of sensory information for guiding motor actions. The first study explored the use of a novel interception task to quantify impairments in the use of proprioceptive and visual feedback to generate rapid motor responses. The Fast Feedback Interception Task (FFIT) was developed to examine the ability to intercept a moving ball with a cursor. Sensory feedback was assessed by either mechanically perturbing the participant’s arm or shifting the visual location of the ball or cursor. Compared to healthy controls, 85% of individuals with stroke displayed impairments using their affected arm. Of note, 75% of individuals with stroke were impaired using their unaffected arm. The second study examined whether individuals with stroke could have distinct impairments in sensory feedback for action and perception. We compared performance on FFIT with a reaching task and an upper limb proprioceptive task. Most individuals with stroke were impaired in FFIT and reaching using their affected arm. Further, most FFIT and reaching task parameters were significantly correlated. We found only a few significant correlations between FFIT and proprioceptive task parameters. The third study examined spatial impairments for individuals with stroke using an 8-target reaching task. Of 265 individuals with stroke, 64% demonstrated impaired reaction time. 35% were impaired in initiating a movement towards a specific region of the workspace and 44% were impaired in all directions of reach. Further, lesions to specific brain regions or white matter tracts were associated with reaction time impairment. Our results highlight the high proportion of individuals with stroke impaired in the use of sensory feedback. Future research is required to understand how these findings can be implemented into clinical practice for guiding diagnosis and tracking stroke recovery.
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