A Multiparameter Approach to Evaluate Post-Stroke Patients: An Application on Robotic Rehabilitation

Abstract

Multidomain instrumental evaluation of post-stroke chronic patients, coupled with standard clinical assessments, has rarely been exploited in the literature. Such an approach may be valuable to provide comprehensive insight regarding patients’ status, as well as orienting the rehabilitation therapies. Therefore, we propose a multidomain analysis including clinically compliant methods as electroencephalography (EEG), electromyography (EMG), kinematics, and clinical scales. The framework of upper-limb robot-assisted rehabilitation is selected as a challenging and promising scenario to test the multi-parameter evaluation, with the aim to assess whether and in which domains modifications may take place. Instrumental recordings and clinical scales were administered before and after a month of intensive robotic therapy of the impaired upper limb, on five post-stroke chronic hemiparetic patients. After therapy, all patients showed clinical improvement and presented pre/post modifications in one or several of the other domains as well. All patients performed the motor task in a smoother way; two of them appeared to change their muscle synergies activation strategies, and most subjects showed variations in their brain activity, both in the ipsi- and contralateral hemispheres. Changes highlighted by the new multiparametric instrumental approach suggest a recovery trend in agreement with clinical scales. In addition, by jointly demonstrating lateralization of brain activations, changes in muscle recruitment and the execution of smoother trajectories, the new approach may help distinguish between true functional recovery and the adoption of suboptimal compensatory strategies. In the light of these premises, the multi-domain approach may allow a finer patient characterization, providing a deeper insight into the mechanisms underlying the relearning procedure and the level (neuro/muscular) at which it occurred, at a relatively low expenditure. The role of this quantitative description in defining a personalized treatment strategy is of great interest and should be addressed in future studies.

Perspectives and Challenges in Robotic Neurorehabilitation

“…So far, multi-domain evaluations (behavioral, muscular, and neural correlates) have not performed continuously, and in our opinion, an elegant robotic solution should be accompanied by validation studies of how the rehabilitation robot impacts the patients' life, by assessing, at the same time, the neural and behavioral correlates' changes and their interplay [167,220]. Hence, combining these assessments might increase the sensitivity to better understand the recovery of the sensorimotor functions, to individuate potential maladaptive compensatory strategies, to plan customized therapeutic intervention, and to monitor disease progression more accurately.…”

Functional synergy recruitment index as a reliable biomarker of motor function and recovery in chronic stroke patients

“…Various groups have also reported altered synergy activation patterns in the paretic UL with respect to the healthy activation coefficients in mild-to-moderately impaired subacute [28,36] and chronic patients [5]. Moreover, various groups have documented slight modifications in the correlation between paretic and healthy synergy temporal activations after rehabilitation [28,29], indicating a certain degree of adaptability in the flow of descending cortical commands. However, it is unclear if the reshaping of recruitment patterns shifted towards the direction of healthy coefficients or maladaptive patterns [28,29].…”

Combined action observation- and motor imagery-based brain computer interface (BCI) for stroke rehabilitation: a case report

“…These results might also be explained by the automatization process in which the participant was used to the cognitive task due to performing it several times, so he may have required less effort to perform the task; consequently, neural activation in the contralateral hemisphere may have decreased (28). However, there was only one participant in this study.…”

“…The value of LC is between -1 and 1, which indicates a higher or lower value in the hemisphere on the opposite side of an imagined hand. This implies how lateralization of the brain functions during the cognitive task (26,28).…”