Impairment and Compensation in Dexterous Upper-Limb Function After Stroke. From the Direct Consequences of Pyramidal Tract Lesions to Behavioral Involvement of Both Upper-Limbs in Daily Activities

Clinician perceptions of a novel wearable robotic hand orthosis for post-stroke hemiparesis

PURPOSE

Wearable robotic devices are currently being developed to improve upper limb function for individuals with hemiparesis after stroke. Incorporating the views of clinicians during the development of new technologies can help ensure that end products meet clinical needs and can be adopted for patient care.

METHODS

In this cross-sectional mixed-methods study, an anonymous online survey was used to gather clinicians' perceptions of a wearable robotic hand orthosis for post-stroke hemiparesis. Participants were asked about their clinical experience and provided feedback on the prototype device after viewing a video.

RESULTS

154 participants completed the survey. Only 18.8% had previous experience with robotic technology. The majority of participants (64.9%) reported that they would use the device for both rehabilitative and assistive purposes. Participants perceived that the device could be used in supervised clinical settings with all phases of stroke. Participants also indicated a need for insurance coverage and quick setup time.

CONCLUSIONS

Engaging clinicians early in the design process can help guide the development of wearable robotic devices. Both rehabilitative and assistive functions are valued by clinicians and should be considered during device development. Future research is needed to understand a broader set of stakeholders' perspectives on utility and design.

Motor Learning Following Stroke: Mechanisms of Learning and Techniques to Augment Neuroplasticity

Sensorimotor impairments are common after stroke requiring stroke survivors to relearn lost motor skills or acquire new ones in order to engage in daily activities. Thus, motor skill learning is a cornerstone of stroke rehabilitation. This article provides an overview of motor control and learning theories that inform stroke rehabilitation interventions, discusses principles of neuroplasticity, and provides a summary of practice conditions and techniques that can be used to augment motor learning and neuroplasticity in stroke rehabilitation.

Dexterity in the Acute Phase of Stroke: Impairments and Neural Substrates

BACKGROUND

Stroke can impair manual dexterity, leading to loss of independence following incomplete recovery. Enhancing our understanding of dexterity impairment may improve neurorehabilitation.

OBJECTIVES

The study aimed to measure dexterity components in acute stroke patients with and without hand motor deficits, compare them to those of healthy controls (HC), and to explore the neural substrates involved in specific components of dexterity.

METHODS

We used the Dextrain Manipulandum to quantify fine finger force control, finger selection accuracy, coactivation, and reaction time (RT). Dexterity was evaluated twice (2 days apart) in 74 patients and 14 HC. Voxel-Lesion-Symptom-Mapping (VLSM) was used to analyze the relationship between tissue damage and dexterity. Results. Due to severe paresis or fatigue, 24 patients could not perform these tasks. In 50 patients (included 4.6 ± 3.3 days post-stroke), finger force control improved (P < .001), as it did in HC (P = .03) who performed better than patients on both evaluations. Accuracy of finger selection did not improve significantly in any group, but the HC performed better on both evaluations. Unexpectedly, coactivation was better in patients than in HC at D3 (P = .03). There were no between-group differences in RT. VLSM showed that damage to the superior temporal gyrus (STG) impaired finger force control while damage to the posterior limb of the internal capsule (PLIC) impaired finger selectivity.

CONCLUSIONS

Acute stroke affecting the STG or PLIC impaired selective components of dexterity. Patients with mild to moderate impairment showed better finger force control and accuracy selection within 48 hours, suggesting the feasibility of detecting early dexterity improvements.

Predicting self-perceived manual ability at three and six months after stroke: A prospective longitudinal study

BACKGROUND

Recovery of manual ability is a critical issue in rehabilitation. Currently, little is known regarding the baseline predictors of self-perceived manual ability, which could capture information on individual's perceived functional ability, especially in carrying-out routine tasks outside clinical settings.

OBJECTIVE

To identify baseline predictors, which can be easily obtained within clinical settings, of self-perceived manual ability at three and six months after discharge from a stroke unit.

METHODS

A 6-month longitudinal study was carried-out. Participants were recruited from a stroke unit of a public hospital. The dependent outcome was self-perceived manual ability, and the following predictors were investigated: age, stroke severity, upper-limb motor impairments, cognitive function, muscle strength, and functional capacity. Linear regression analyses were employed to identify multivariate predictors of manual ability at three and six months after discharge (α=5%).

RESULTS

Participated 131 individuals, 69 women (mean age of 60 years). Regression analyses revealed that stroke severity and age accounted for 31% and 47% of the variance in manual ability at three and six months after stroke, respectively. Stroke severity was the best predictor of manual ability at three (R2=29%; F=44.7; p<0.0001) and six months (R2=45%; F=88.2; p<0.0001) after stroke, respectively.

CONCLUSION

Stroke severity showed to be the best predictor of manual ability at both three and six months after stroke. Although significant, age added little to the explained variance.

Neural oscillations after acute large artery atherosclerotic cerebral infarction during resting state and sleep spindles

Electroencephalogram-microstate analysis was conducted using low-resolution electromagnetic tomography (LORETA)-KEY to evaluate dynamic brain network changes in patients with acute large artery atherosclerotic cerebral infarction (LAACI) during the rest and sleep stages. This study included 35 age- and sex-matched healthy controls and 34 patients with acute LAACI. Each participant performed a 3-h, 19-channel video electroencephalogram test. Subsequently, 20 epochs of 2-s sleep spindles during stage N2 sleep and five epochs of 10-s electroencephalogram data in the resting state for each participant were obtained. In both the resting state and sleep spindles, patients with LAACI displayed altered neural oscillations. The parameters of microstate A (coverage, occurrence, and duration) increased during the resting state in the patients with LAACI compared with healthy controls. The coverage and occurrence of microstate B and D were reduced in the LAACI group compared with the healthy controls (p < 0.05). Moreover, during sleep spindles, the duration of microstate A and the transition probability from microstate A and B to C decreased, but the coverage of microstate B and the transition rate from microstate B to D increased (p < 0.05) in the LAACI group compared with the healthy controls. These results enable better understanding of how neural oscillations are modified in patients with LAACI during the resting state and sleep spindles. Following LAACI, the dynamic brain network undergoes changes during sleep spindles and the resting state. Continued long-term investigations are required to determine how well these changes in brain dynamics reflect the clinical characteristics of patients with LAACI.

Surface-Electromyography-Based Co-Contraction Index for Monitoring Upper Limb Improvements in Post-Stroke Rehabilitation: A Pilot Randomized Controlled Trial Secondary Analysis

Persons post-stroke experience excessive muscle co-contraction, and consequently the arm functions are compromised during the activities of daily living. Therefore, identifying instrumental outcome measures able to detect the motor strategy adopted after a stroke is a primary clinical goal. Accordingly, this study aims at verifying whether the surface electromyography (sEMG)-based co-contraction index (CCI) could be a new clinically feasible approach for assessing and monitoring patients' motor performance. Thirty-four persons post-stroke underwent clinical assessment and upper extremity kinematic analysis, including sEMG recordings. The participants were randomized into two treatment groups (robot and usual care groups). Ten healthy subjects provided a normative reference (NR). Frost's CCI was used to quantify the muscle co-contraction of three different agonist/antagonist muscle pairs during an object-placing task. Persons post-stroke showed excessive muscle co-contraction (mean (95% CI): anterior/posterior deltoid CCI: 0.38 (0.34-0.41) p = 0.03; triceps/biceps CCI: 0.46 (0.41-0.50) p = 0.01) compared to NR (anterior/posterior deltoid CCI: 0.29 (0.21-0.36); triceps/biceps CCI: 0.34 (0.30-0.39)). After robot therapy, persons post-stroke exhibited a greater improvement (i.e., reduced CCI) in proximal motor control (anterior/posterior deltoid change score of CCI: -0.02 (-0.07-0.02) p = 0.05) compared to usual care therapy (0.04 (0.00-0.09)). Finally, the findings of the present study indicate that the sEMG-based CCI could be a valuable tool in clinical practice.

Virtual reality a technological miracle transforming physical rehabilitation: A scoping review

Physical rehabilitation is evolving day by day. In the same way, simulation in rehabilitation is increasing and has now become a cornerstone for rehabilitation programs. Increase in the number of new protocols, clinical methods, and treatment standardization, virtual reality is appearing as a new medium to deliver the simulation. Virtual reality gives the benefits of forming standardized treatment protocols on demand for various conditions repetitively with a cost-effective delivery system. This was an observational retrospective study. The PubMed database was used to obtain the available material related to virtual reality and rehabilitation and was searched using the same keywords. The articles were then sorted as the subject to the recent decade. The basic information was then obtained, which included timespan, sources of the document, average years of publication, document types we collected, and average citation per year per document. Analysis of the literature that was available online related to virtual reality and rehabilitation between 2011 and 2021 generated a list of 813 documents from 275 sources, of which 810 were from journal articles and 3 were book chapters with an average year of publication of 2.16. The highest number of publications was 480 in 2020, followed by 150 in 2019, 95 in 2018, and 28 in 2017. The annual growth rate percentage of scientific publications was 26.1%. Therefore, more studies should be performed on virtual reality.

Patients' physiological reactions to competitive rehabilitation therapies assisted by robotic devices

BACKGROUND

The aging of the population and the progressive increase in life expectancy in developed countries is leading to a high incidence of cerebrovascular diseases. Several studies have demonstrated that robot-assisted rehabilitation therapies combined with serious games can improve rehabilitation outcomes. Social interaction in the form of multiplayer games has been highlighted as a potential element to increase patient's motivation and exercise intensity, which professionals have described as one of the determining factors in maximizing rehabilitation outcomes. Despite this, it has not been widely studied. Physiological measures have been proven as an objective tool to evaluate patients' experience in robot-assisted rehabilitation environments. However, they have not been used to evaluate patients' experience in multiplayer robot-assisted rehabilitation therapies. The main objective of this study is to analyze whether the interpersonal interaction inherent in a competitive game mode affects the patients' physiological responses in robot-assisted rehabilitation environments.

METHODS

A total of 14 patients participated in this study. The results of a competitive game mode were compared with a single-player game mode with different difficulty levels. Exercise intensity and performance were measured through parameters extracted from the game and the information provided by the robotic rehabilitation platforms. The physiological response of patients in each game mode was measured by the heart rate (HR) and the galvanic skin response (GSR). Patients were asked to fill out the IMI and the overall experience questionnaire.

RESULTS

The exercise intensity results show that high-difficulty single-player game mode is similar in terms of intensity level to a competitive game mode, based on velocity values, reaction time and questionnaire results. However, the results of the physiological responses of the patients measured by GSR and HR are lower in the case of the competitive mode compared to the high-difficulty single-player game mode, obtaining results similar to those obtained in the low-difficulty single-player game mode.

CONCLUSIONS

Patients find the competitive game mode the most fun, which is also the mode they report experiencing the most effort and stress level. However, this subjective evaluation is not in line with the results of physiological responses. This study concludes that interpersonal interaction inherent to a competitive game mode influences patients' physiological responses. This could mean that social interaction is an important factor to consider when interpreting the results obtained from physiological measurements.

Object-centered sensorimotor bias of torque control in the chronic stage following stroke

When lifting objects whose center of mass (CoM) are not centered below the handle one must compensate for arising external torques already at lift-off to avoid object tilt. Previous studies showed that finger force scaling during object lifting may be impaired at both hands following stroke. However, torque control in object manipulation has not yet been studied in patients with stroke. In this pilot study, thirteen patients with chronic stage left hemispheric stroke (SL), nine patients with right hemispheric stroke (SR) and hand-matched controls had to grasp and lift an object with the fingertips of their ipsilesional hand at a handle while preventing object tilt. Object CoM and therewith the external torque was varied by either relocating a covert weight or the handle. The compensatory torque at lift-off (Tcom) is the sum of the torque resulting from (1) grip force being produced at different vertical finger positions (∆CoP × GF) and (2) different vertical load forces on both sides of the handle (∆Fy × w/2). When having to rely on sensorimotor memories, ∆CoP × GF was elevated when the object CoM was on the ipsilesional-, but decreased when CoM was on the contralesional side in SL, whereas ∆Fy × w/2 was biased in the opposite direction, resulting in normal Tcom. SR patients applied a smaller ∆CoP × GF when the CoM was on the contralesional side. Torques were not altered when geometric cues were available. Our findings provide evidence for an object-centered spatial bias of manual sensorimotor torque control with the ipsilesional hand following stroke reminiscent of premotor neglect. Both intact finger force-to-position coordination and visuomotor control may compensate for the spatial sensorimotor bias in most stroke patients. Future studies will have to confirm the found bias and evaluate the association with premotor neglect.

Design of Spiral-Cable Forearm Exoskeleton to Assist Supination for Hemiparetic Stroke Subjects

We present the development of a cable-based passive forearm exoskeleton that is designed to assist supination for hemiparetic stroke survivors. Our device uniquely provides torque sufficient for counteracting spasticity within a below-elbow apparatus. The mechanism consists of a spiral single-tendon routing embedded in a rigid forearm brace and terminated at the hand and upper-forearm. A spool with an internal releasable-ratchet mechanism allows the user to manually retract the tendon and rotate the hand to counteract involuntary pronation synergies due to stroke. We characterize the mechanism with benchtop testing and five healthy subjects, and perform a preliminary assessment of the exoskeleton with a single chronic stroke subject having minimal supination ability. The mechanism can be integrated into an existing active hand-opening orthosis to enable supination support during grasping tasks, and also allows for a future actuated supination strategy.

Case Report: True Motor Recovery of Upper Limb Beyond 5 Years Post-stroke

Most of motor recovery usually occurs within the first 3 months after stroke. Herein is reported a remarkable late recovery of the right upper-limb motor function after a left middle cerebral artery stroke. This recovery happened progressively, from two to 12 years post-stroke onset, and along a proximo-distal gradient, including dissociated finger movements after 5 years. Standardized clinical assessment and quantified analysis of the reach-to-grasp movement were repeated over time to characterize the recovery. Twelve years after stroke onset, diffusion tensor imaging (DTI), functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation (TMS) analyses of the corticospinal tracts were carried out to investigate the plasticity mechanisms and efferent pathways underlying motor control of the paretic hand. Clinical evaluations and quantified movement analysis argue for a true neurological recovery rather than a compensation mechanism. DTI showed a significant decrease of fractional anisotropy, associated with a severe atrophy, only in the upper part of the left corticospinal tract (CST), suggesting an alteration of the CST at the level of the infarction that is not propagated downstream. The finger opposition movement of the right paretic hand was associated with fMRI activations of a broad network including predominantly the contralateral sensorimotor areas. Motor evoked potentials were normal and the selective stimulation of the right hemisphere did not elicit any response of the ipsilateral upper limb. These findings support the idea that the motor control of the paretic hand is mediated mainly by the contralateral sensorimotor cortex and the corresponding CST, but also by a plasticity of motor-related areas in both hemispheres. To our knowledge, this is the first report of a high quality upper-limb recovery occurring more than 2 years after stroke with a genuine insight of brain plasticity mechanisms.

[Functional and activity limitations in patients after a stroke]

One of the main characteristics of the goal of rehabilitation after a stroke is the focus on restoring a certain level of functioning. The formation of the goal of rehabilitation and the implementation of effective rehabilitation are possible when taking into account not only the clinical diagnosis, but also the problems and possibilities of the patient in the categories of the International Classification of Functioning, Disabilities and Health (ICF).

PURPOSE OF THE STUDY

To assess the types and degree of functional limitations and activity limitations in patients after ischemic and hemorrhagic strokes in the early recovery period, taking into account the type of stroke and the affected vascular pool.

MATERIAL AND METHODS

528 patients after a stroke were examined. Functional limitations and activity limitations were assessed in ICF categories, taking into account the type of stroke (hemorrhagic, ischemic) and the affected vascular system (carotid, vertebrobasilar), including dysfunctions (motor, global and specific mental functions, balance function, functions of the cardiovascular system), activity restrictions (limitations of paretic limbs mobility, functional independence from others). To quantify the degree of limitation, generally accepted rating scales were used (Medical Research Council Scale, Modified Ashworth Scale of muscle spasticity, Frenchay arm test, Hauser ambulation index, Rivermead mobility index, Functional Independence Measure, «Memory for images», «Learning 10 words», «Red-black Schulte-Platonov tables», Luscher color test, The hospital Anxiety and Depression Scale, Recovery Locus of Control), stabilography method, registration of office and outpatient blood pressure.

RESULTS

Limitations of the functions of paretic limbs and activity associated with maintaining body position, walking, movement, transfer, manipulation of objects and self-care, dependence on others in everyday life were found in most patients after hemorrhagic stroke (in 94-95%) and ischemic (in 88-93%) stroke in the carotid pool, while more severe disorders were recorded in cases of hemorrhagic type of stroke. Violation of global mental functions was recorded in ¼ of patients, specific mental functions - in 60-75% of patients after hemorrhagic stroke and ischemic stroke in the carotid pool. In ischemic stroke happens in the vertebrobasilar basin, the limitations of the daily activity of patients were determined by the violation of static and dynamic balance; a mild degree of impairment of specific mental functions and limitation of activity (self-service) were also recorded.

CONCLUSION

After a stroke, motor function disorders, mobility limitations of paretic limbs and self-service, postural disorders are recorded. After an ischemic stroke in the vertebrobasilar basin, the restrictions on the activity of patients are determined by postural disorders. Taking into account the identified features of functional limitations and activity limitations in patients after a stroke will allow developing a differentiated approach not only to the formation of goals and objectives of rehabilitation, but also to the choice of rehabilitation methods.