A case to be made: theoretical and empirical arguments for the need to consider fatigue in post-stroke motor rehabilitation

EEG Spectral Feature Modulations Associated With Fatigue in Robot-Mediated Upper Limb Gross and Fine Motor Interactions

This paper investigates the EEG spectral feature modulations associated with fatigue induced by robot-mediated upper limb gross and fine motor interactions. Twenty healthy participants were randomly assigned to perform a gross motor interaction with HapticMASTER or a fine motor interaction with SCRIPT passive orthosis for 20 min or until volitional fatigue. Relative and ratio band power measures were estimated from the EEG data recorded before and after the robot-mediated interactions. Paired-samples t-tests found a significant increase in the relative alpha band power and a significant decrease in the relative delta band power due to the fatigue induced by the robot-mediated gross and fine motor interactions. The gross motor task also significantly increased the (θ + α)/β and α/β ratio band power measures, whereas the fine motor task increased the relative theta band power. Furthermore, the robot-mediated gross movements mostly changed the EEG activity around the central and parietal brain regions, whereas the fine movements mostly changed the EEG activity around the frontopolar and central brain regions. The subjective ratings suggest that the gross motor task may have induced physical fatigue, whereas the fine motor task may have induced mental fatigue. Therefore, findings affirm that changes to localised brain activity patterns indicate fatigue developed from the robot-mediated interactions. It can also be concluded that the regional differences in the prominent EEG spectral features are most likely due to the differences in the nature of the task (fine/gross motor and distal/proximal upper limb) that may have differently altered an individual's physical and mental fatigue level. The findings could potentially be used in future to detect and moderate fatigue during robot-mediated post-stroke therapies.

Prediction of Balance After Inpatient Rehabilitation in Stroke Subjects with Severe Balance Alterations at the Admission

BACKGROUND

Patients with severe motor alterations would be those on who the prediction of the expected motor response after inpatient rehabilitation programs is most required.

OBJECTIVES

To analyze if the balance progress measured by the Berg Balance Scale and the time of hospitalization could be independent predictors of the Berg Balance at the end of a post stroke rehabilitation program in patients with severe balance alteration at the admission. Secondly, to compare a Berg Balance prediction model at the time of discharge based on the Berg Balance at the time of admission (model 1) to a Berg Balance prediction model at the time of discharge based on Berg Balance progress and the time of hospitalization (model 2).

METHODS

Subjects suffering a first subacute supratentorial stroke admitted for inpatient rehabilitation between 2010 through 2018 were included to develop two linear regression models of predicted Berg Balance at discharge (n=149).

RESULTS

According to model 1 (p < 0.0001, R²= 0.166), the Berg Balance at the admission would be a predictor of the Berg Balance at discharge from hospitalization. According to model 2 (p < 0.0001, R²= 0.993) the Berg Balance progress (β= 1.026; p < 0.0001) and the hospitalization time (β=-0.006; p < 0.0001) would be independent predictors of the Berg Balance at discharge.

CONCLUSIONS

The motor response to the rehabilitation programs in subacute patients with severe motor alterations could be explained on the basis of balance condition at the admission, but this explanation may be improved considering the progress on the balance the patients achieve during inpatient rehabilitation irrespective the time of hospitalization.

Application of Transcranial Direct Current Stimulation in Neurorehabilitation: The Modulatory Effect of Sleep

The relationship between sleep disorders and neurological disorders is often reciprocal, such that sleep disorders are worsened by neurological symptoms and that neurological disorders are aggravated by poor sleep. Animal and human studies further suggest that sleep disruption not only worsens single neurological symptoms but may also lead to long-term negative outcomes. This suggests that sleep may play a fundamental role in neurorehabilitation and recovery. We further propose that sleep may not only alter the efficacy of behavioral treatments but also plasticity-enhancing adjunctive neurostimulation methods, such as transcranial direct current stimulation (tDCS). At present, sleep receives little attention in the fields of neurorehabilitation and neurostimulation. In this review, we draw together the strands of evidence from both fields of research to highlight the proposition that sleep is an important parameter to consider in the application of tDCS as a primary or adjunct rehabilitation intervention.

Upper Limb Immobilisation: A Neural Plasticity Model with Relevance to Poststroke Motor Rehabilitation

Advances in our understanding of the neural plasticity that occurs after hemiparetic stroke have contributed to the formulation of theories of poststroke motor recovery. These theories, in turn, have underpinned contemporary motor rehabilitation strategies for treating motor deficits after stroke, such as upper limb hemiparesis. However, a relative drawback has been that, in general, these strategies are most compatible with the recovery profiles of relatively high-functioning stroke survivors and therefore do not easily translate into benefit to those individuals sustaining low-functioning upper limb hemiparesis, who otherwise have poorer residual function. For these individuals, alternative motor rehabilitation strategies are currently needed. In this paper, we will review upper limb immobilisation studies that have been conducted with healthy adult humans and animals. Then, we will discuss how the findings from these studies could inspire the creation of a neural plasticity model that is likely to be of particular relevance to the context of motor rehabilitation after stroke. For instance, as will be elaborated, such model could contribute to the development of alternative motor rehabilitation strategies for treating poststroke upper limb hemiparesis. The implications of the findings from those immobilisation studies for contemporary motor rehabilitation strategies will also be discussed and perspectives for future research in this arena will be provided as well.