The Impact of Cognitive Impairment on Robot-Based Upper-Limb Motor Assessment in Chronic Stroke

Abstract

Background Chronic upper extremity motor deficits are present in up to 65% of stroke survivors, and cognitive impairment is prevalent in 46-61% of stroke survivors even 10 years after their stroke. Robot-assisted therapy programs tend to focus on motor recovery and do not include stroke patients with cognitive impairment. Objective This study aims to investigate performance on the individual cognitive domains evaluated in the MoCA and their relation to upper-limb motor performance on a robotic system. Methods Participants were recruited from the stroke population with a wide range of cognitive and motor levels to complete a trajectory tracking task using the Haptic TheraDrive rehabilitation robot system. Motor performance was evaluated against standard clinical cognitive and motor assessments. Our hypothesis is that the cognitive domains involved in the visuomotor tracking task are significant predictors of performance on the robot-based task and that impairment in these domains results in worse motor performance on the task compared to subjects with no cognitive impairment. Results Our results support the hypothesis that visuospatial and executive function have a significant impact on motor performance, with differences emerging between different functional groups on the various robot-based metrics. We also show that the kinematic metrics from this task differentiate cognitive-motor functional groups differently. Conclusion This study demonstrates that performance on a motor-based robotic assessment task also involves a significant visuospatial and executive function component and highlights the need to account for cognitive impairment in the assessment of motor performance.