Gait Training with Bilateral Rhythmic Auditory Stimulation in Stroke Patients: A Randomized Controlled Trial

Music therapy with adults in the subacute phase after stroke: A study protocol

Stroke is a highly disabling condition, for which music therapy is regularly used in rehabilitation. One possible mechanism for the effects of music therapy is the motivational aspect of music, for example regarding treatment adherence based on improved mood. In this study, changes in motivation related to Neurologic Music Therapy (NMT) techniques during rehabilitation in the subacute phase after stroke will be investigated. Using a randomised within-subjects cross-over design, the effects of two NMT techniques and related motivational indices will be investigated. Data will be collected at three timepoints: baseline (TP1), after being randomised into groups and receiving NMT or standard care (TP2), and then at a third time point after the cross-over and having received both conditions (TP3). This design allows to counteract order effects, time effects due to spontaneous and/or nonlinear recovery, as well as single-subject comparisons in a relatively heterogeneous sample. Twenty adult participants who have experienced a supratentorial ischaemic or haemorrhagic stroke and are experiencing upper-limb impairments and/or cognitive deficits will be included. Behavioural measures of motor function, cognition, and quality of life will be collected, along with self-reported indices of overall motivation. The study outcomes will have implications for the understanding of the underlying mechanisms of music therapy in stroke recovery, more specifically regarding the relevance of motivational states in neurorehabilitation.

Correlations in abnormal synergies between the upper and lower extremities across various phases of stroke

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations (r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke (P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations.NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Hearing loss, gait and balance impairments and falls among individuals with sub-acute stroke: A comparative cross-sectional study

Background

The impact of hearing loss in stroke is less explored. This study aimed to compare hearing loss in patients with sub-acute stroke with healthy controls and evaluate its association with gait and balance impairments and falls.

Methods

This study involved 78 ambulant sub-acute stroke patients and 78 age-sex-matched controls. Hearing loss was assessed with pure tone average, while gait and balance impairments were assessed with the Timed Up and Go test, Berg Balance Scale, Functional Gait Assessment and 10-m walk test (gait speed). Fall occurrence was evaluated by a self-report questionnaire.

Results

The prevalence of hearing loss (pure tone average of >25 dB) was higher in stroke patients than in controls (64.1% vs. 35.9%; p < 0.001). The mean pure tone average of stroke patients showed a significant positive correlation with Timed Up and Go test (r = 0.357; p = 0.001) and fall occurrence (r = 0.253; p = 0.025), and a significant negative correlation with Berg Balance Scale (r = -0.299; p = 0.008) and Functional Gait Assessment (r = -0.452; p < 0.001). There was a non-significant negative correlation with gait speed (r = -0.166; p = 0.147). Multiple regression showed that mean pure tone average was associated with Timed Up and Go test (B = 0.096; 95%CI: 0.010, 0.183) and Functional Gait Assessment (B = -0.087; 95%CI: -0.157, -0.017), but not with gait speed (B = -0.003; 95%CI: -0.007, 0.001) and Berg Balance Scale (B = -0.058; 95%CI: -0.165, 0.049).

Conclusion

Hearing loss is more prevalent among patients with sub-acute stroke compared with age-sex-matched controls. Hearing loss is also associated with gait and balance impairments and falls among sub-acute stroke patients. We recommend that hearing screening and rehabilitation be incorporated into post-stroke rehabilitation programmes as part of strategies to improve balance and gait and reduce or prevent falls.

Interactions in abnormal synergies between the upper and lower extremities in various phases of stroke: A cohort study

Objective

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However less attention has been paid to the inter-limb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke.

Methods

In this study, we used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis post stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy post stroke.

Results

We found that generally, strong inter-limb correlations (r>0.65 with all p-values<0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). But correlations of lower-extremity extension synergy with upper-extremity flexion synergy and extension synergy decreased (down to r=0.38) around 360 days after stroke (p<0.05).

Interpretation

These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances inter-limb correlations between the flexion synergy and extension, however a recovery of the CST or/and the functional fragmentation (remodeling) of the alternative neural substrates in the chronic phase contribute to diversity in neural pathways in motor execution, eventually leading to reduced inter-limb correlations.

Efficacy and safety of using auditory-motor entrainment to improve walking after stroke: a multi-site randomized controlled trial of InTandemTM

Walking slowly after stroke reduces health and quality of life. This multi-site, prospective, interventional, 2-arm randomized controlled trial (NCT04121754) evaluated the safety and efficacy of an autonomous neurorehabilitation system (InTandemTM) designed to use auditory-motor entrainment to improve post-stroke walking. 87 individuals were randomized to 5-week walking interventions with InTandem or Active Control (i.e., walking without InTandem). The primary endpoints were change in walking speed, measured by the 10-meter walk test pre-vs-post each 5-week intervention, and safety, measured as the frequency of adverse events (AEs). Clinical responder rates were also compared. The trial met its primary endpoints. InTandem was associated with a 2x larger increase in speed (Δ: 0.14 ± 0.03 m/s versus Δ: 0.06 ± 0.02 m/s, F(1,49) = 6.58, p = 0.013), 3x more responders (40% versus 13%, χ2(1) ≥ 6.47, p = 0.01), and similar safety (both groups experienced the same number of AEs). The auditory-motor intervention autonomously delivered by InTandem is safe and effective in improving walking in the chronic phase of stroke.

The effects of rhythmic auditory stimulation on functional ambulation after stroke: a systematic review

BACKGROUND

Several studies have reported the effect of rhythmic auditory stimulation (RAS) on functional ambulation in stroke patients, yet no systematic overview has yet been published. This study aims to synthesize the available evidence describing changes in stroke patients after RAS intervention for functional ambulation and the use of walking assistive devices, and to find out if the effect of RAS and music-based RAS differs depending on the lesioned area.

METHODS

The PubMed, PEDro, Cochrane Central Register of Controlled Trials, Web of Science, Scopus and CINAHL electronic databases were searched for reports evaluating the effect of RAS on walking in stroke patients, applying the PICOS criteria for the inclusion of studies.

RESULTS

Twenty one articles were included (948 stroke survivors). Most studies were of good methodological quality according to the PEDro scale, but they had a high risk of bias. The most consistent finding was that RAS improves walking and balance parameters in stroke patients in all phases compared to baseline and versus control groups with conventional treatment. Functional ambulation and the use of walking assistive devices were inconsistently reported. Several studies also suggest that RAS may be as good as other complementary therapies (horse-riding and visual cueing).

CONCLUSIONS

Despite the beneficial effects of RAS, the question remains as to whether it is better than other complementary therapies. Given the heterogeneity of the interventions, the interventions in control groups, the varied durations, and the different outcome measures, we suggest that care should be taken in interpreting and generalizing findings.

PROSPERO REGISTRATION

CRD42021277940.

Acupuncture for gait disturbance of patients with subacute and chronic stroke: a systematic review and meta-analysis protocol

INTRODUCTION

Hemiparetic gait is one of the most common sequelae of a stroke. Acupuncture has shown potential in correcting hemiplegic gait patterns and improving motor function recovery after stroke. However, controversial findings and a lack of supportive evidence on the effectiveness of acupuncture for post-stroke hemiplegia. The intelligent gait analysis system provides a new perspective for the study of hemiparetic gait. This systematic review aims to collect relevant studies and critically evaluate the efficacy and safety of acupuncture in alleviating gait disturbance of post-stroke hemiplegia based on quantified gait parameters.

METHODS AND ANALYSIS

A comprehensive search of PubMed, Embase, Cochrane stroke group trials register, Cochrane Central Register of Controlled Trials, CINAHL, AMED, three Chinese databases (Chinese Biomedical Literatures database (CBM), National Knowledge Infrastructure (CNKI), and Wan fang Digital Periodicals), four trails registries (The WHO International Clinical Trials Registry Platform, The Chinese Clinical Trial Registry, The US National Institutes of Health Ongoing Trials Register, and The Australian New Zealand Clinical Trials Registry) will be conducted to identify randomised controlled trials of acupuncture for gait disturbance in post-stroke patients. No restrictions on language or publication status. The primary outcomes are gait temporospatial parameters (eg, step length, stride length, step width, step frequency (cadence), walking speed, etc), and gait kinematic parameters (eg, hip peak flex/extend angle, knee peak flex/extend angle, ankle peak dorsi/plantar-flexion angle, etc). We will assess bias using the approach recommended by the Cochrane Handbook for Systematic Reviews of Interventions. A meta-analysis will be conducted to synthesise the evidence for each outcome measure. The χ² test and I² statistic will be used for assessing heterogeneity between studies.

ETHICS AND DISSEMINATION

No ethical approval is needed because no primary data is collected. Scientific conferences or peer-reviewed journals will publish the findings.

PROSPERO REGISTRATION NUMBER

CRD42022384348.

Effects of rhythmic auditory stimulation on motor function and balance ability in stroke: A systematic review and meta-analysis of clinical randomized controlled studies

OBJECTIVE

Rhythmic auditory stimulation (RAS) belongs to neurologic music therapy, which has attracted clinical attention because of its efficacy in motor function after stroke. This study aimed to summarize the effectiveness of rhythmic auditory stimulation (RAS) for the treatment of motor function and balance ability in stroke through a systematic review and meta-analysis.

METHODS

All studies were retrieved from six databases. The effects of RAS on stroke were determined using the following indicators: motor function including step length, step cadence, velocity, Fugl-Meyer assessment (FMA); and balance ability including overall balance index (OBI) and Berg Balance Scale (BBS). The risk map of bias of the quality of the studies and the meta-analysis results of the indicators was prepared using RevMan 5.2 software.

RESULTS

A total of 1,363 abstracts were retrieved. Among them, 325 duplicate studies were eliminated, and 971 studies were excluded after reading the titles and abstracts. In addition, by downloading the full text for further reading and screening, 47 studies were excluded. A total of 22 studies were included in the systematic review, and 18 studies were included in the meta-analysis. Assessment of quality, based on the PEDro scale, two studies had low quality, three studies had excellent quality, and the other studies had good quality; based on the Cochrane Collaborative Network Bias Risk Assessment Scale. A total of 15 studies specifically explained the random methods used. Meanwhile, seven studies did not report random sequence generation. A total of 10 studies reported that the evaluation of experimental results was blinded. In the meta-analysis, the results of motor function [namely, velocity (SMD = 0.99, 95% CI (0.43, 1.55)), step length (SMD = 0.97, 95% CI (0.74, 1.20)), and step cadence (MD = 5.16, 95% CI (4.17, 6.14)), FMA (MD = 2.93, 95% CI (2.04, 3.83))], were statistically significant (P < 0.01). The results of balance ability [OBI (MD = -0.51, 95% CI (-0.86, -0.16)) and BBS (MD = 2.93, 95% CI (1.67, 4.20))], were also statistically significant (P < 0.01). Among all the outcome indicators, three indicators were included in more than 10 studies: these are step length, step cadence, and velocity. The results showed that the two sides of the funnel chart were asymmetrical, thus these results all showed heterogeneity. The GRADEpro GDT online tool was used to evaluate the quality of evidence for the outcome indicators in the included studies. Five outcome indicators were included, of which three were low-quality indicators and two were moderate-quality indicators.

CONCLUSIONS

RAS could improve gait parameters, walking function, and balance ability of individuals with stroke. However, studies or samples of outcome indicators for balance ability of stroke patients is relatively insufficient, which also requires further research in the future.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier: CRD42021225102.

Neurologic Music Therapy in Geriatric Rehabilitation: A Systematic Review

(1) Introduction: Neurologic music therapy (NMT) is a non-pharmacological approach of interaction through the therapeutic use of music in motor, sensory and cognitive dysfunctions caused by damage or diseases of the nervous system. (2) Objective: This study aimed to critically appraise the available literature on the application of particular NMT techniques in the rehabilitation of geriatric disorders. (3) Methods: PubMed, ScienceDirect and EBSCOhost databases were searched. We considered randomized controlled trials (RCTs) from the last 12 years using at least one of the NMT techniques from the sensorimotor, speech/language and cognitive domains in the therapy of patients over 60 years old and with psychogeriatric disorders. (4) Results: Of the 255 articles, 8 met the inclusion criteria. All papers in the final phase concerned the use of rhythmic auditory stimulation (RAS) (sensorimotor technique) in the rehabilitation of both Parkinson's disease (PD) patients (six studies) and stroke patients (SPs) (two studies). (5) Conclusion: All reports suggest that the RAS technique has a significant effect on the improvement of gait parameters and the balance of PD patients and SPs, as well as the risk of falls in PD patients.

A Tailored Music-Motor Therapy and Real-Time Biofeedback Mobile Phone App (‘GotRhythm’) to Promote Rehabilitation Following Stroke: A Pilot Study

Background:

Stroke persists as an important cause of long-term disability world-wide with the need for rehabilitation strategies to facilitate plasticity and improve motor function in stroke survivors. Rhythm-based interventions can improve motor function in clinical populations. This study tested a novel music-motor software application ‘GotRhythm’ on motor function after stroke.

Methods:

Participants were 22 stroke survivors undergoing inpatient rehabilitation in a subacute stroke ward. Participants were randomised to the GotRhythm intervention (combining individualised music and augmented auditory feedback along with wearable sensors to deliver a personalised rhythmic auditory stimulation training protocol) or usual care. Intervention group participants were offered 6-weeks of the GotRhythm intervention, consisting of a supervised 20-minute music-motor therapy session using GotRhythm conducted 3 times a week for 6 weeks. The primary feasibility outcomes were adherence to the intervention and physical function (change in the Fugl-Meyer Assessment of Motor Recovery score) measured at baseline, after 3-weeks and at end of the intervention period (6-weeks).

Results:

Three of 10 participants randomised to the intervention did not receive any of the GotRhythym music-motor therapy. Of the remaining 7 intervention group participants, only 5 completed the 3-week mid-intervention assessment and only 2 completed the 6-week post-intervention assessment. Participants who used the intervention completed 5 (IQR 4,7) sessions with total ‘dose’ of the intervention of 70 (40, 201) minutes.

Conclusion:

Overall, adherence to the intervention was poor, highlighting that application of technology assisted music-based interventions for stroke survivors in clinical environments is challenging along with usual care, recovery, and the additional clinical load.

The Effect of Music-Based Rhythmic Auditory Stimulation on Balance and Functional Outcomes after Stroke

Purpose: the purpose of this paper was to evaluate the effects of music-based rhythmic auditory stimulation on balance and motor function after stroke and whether there are differences depending on the affected hemisphere, lesion site and age. Materials and Methods: This study was an observational and longitudinal study. Adult stroke survivors (n = 28), starting no later than 3 weeks after a stroke, conducted 90 min sessions of music-based rhythmic auditory stimulation 3 days a week, in addition to 60 min a day of conventional physiotherapy. Balance ability was evaluated using the Mini Best Test and the Tinetti Test; motor function was evaluated using the Motor Assessment Scale. Results: All of the participants significantly improved their balance ability and motor function variables upon comparing scores at discharge and admission. Intragroup differences were observed upon comparing subgroups of patients by lesion site and by the degree of motor impairment. Age, stroke type and affected hemisphere seemed not to be directly related to the amount of improvement. Conclusions: This study suggests that the effects of music-based rhythmic auditory stimulation (RAS) on balance ability and motor function varies depending on the scale or test used for evaluation and on the variables that the tests measure. Patients with hemiparesis seemed to improve more than those with hemiplegia.

The Short-Term Effects of Rhythmic Vibrotactile and Auditory Biofeedback on the Gait of Individuals After Weight-Induced Asymmetry

BACKGROUND

Biofeedback (BFB), the practice of providing real-time sensory feedback has been shown to improve gait rehabilitation outcomes. BFB training through rhythmic stimulation has the potential to improve spatiotemporal gait asymmetries while minimizing cognitive load by encouraging a synchronization between the user's gait cycle and an external rhythm.

OBJECTIVE

The purpose of this work was to evaluate if rhythmic stimulation can improve the stance time symmetry ratio (STSR) and to compare vibrotactile to auditory stimulation. Gait parameters including velocity, cadence, stride length, double support time, and step length symmetry, were also examined.

METHODOLOGY

An experimental rhythmic stimulation system was developed, and twelve healthy adults (5 males), age 28.42 ± 10.93 years, were recruited to participate in walking trials. A unilateral ankle weight was used to induce a gait asymmetry to simulate asymmetry as commonly exhibited by individuals with lower limb amputation and other clinical disorders. Four conditions were evaluated: 1) No ankle weight baseline, 2) ankle weight without rhythmic stimulation, 3) ankle weight + rhythmic vibrotactile stimulation (RVS) using alternating motors and 4) ankle weight + rhythmic auditory stimulation (RAS) using a singletone metronome at the participant's self-selected cadence.

FINDINGS

As expected the STSR became significantly more asymmetrical with the ankle weight (i.e. induced asymmetry condition). STSR improved significantly with RVS and RAS when compared to the ankle weight without rhythmic stimulation. Cadence also significantly improved with RVS and RAS compared to ankle weight without rhythmic stimulation. With the exception of double support time, the other gait parameters were unchanged from the ankle weight condition. There were no statistically significant differences between RVS and RAS.

CONCLUSION

This study found that rhythmic stimulation can improve the STSR when an asymmetry is induced. Moreover, RVS is at least as effective as auditory stimulation in improving STSR in healthy adults with an induced gait asymmetry. Future work should be extended to populations with mobility impairments and outside of laboratory settings.

Rhythm and Music-Based Interventions in Motor Rehabilitation: Current Evidence and Future Perspectives

Research in basic and clinical neuroscience of music conducted over the past decades has begun to uncover music’s high potential as a tool for rehabilitation. Advances in our understanding of how music engages parallel brain networks underpinning sensory and motor processes, arousal, reward, and affective regulation, have laid a sound neuroscientific foundation for the development of theory-driven music interventions that have been systematically tested in clinical settings. Of particular significance in the context of motor rehabilitation is the notion that musical rhythms can entrain movement patterns in patients with movement-related disorders, serving as a continuous time reference that can help regulate movement timing and pace. To date, a significant number of clinical and experimental studies have tested the application of rhythm- and music-based interventions to improve motor functions following central nervous injury and/or degeneration. The goal of this review is to appraise the current state of knowledge on the effectiveness of music and rhythm to modulate movement spatiotemporal patterns and restore motor function. By organizing and providing a critical appraisal of a large body of research, we hope to provide a revised framework for future research on the effectiveness of rhythm- and music-based interventions to restore and (re)train motor function.

Improvement of Gait in Patients with Stroke Using Rhythmic Sensory Stimulation: A Case-Control Study

Patients with stroke suffer from impaired locomotion, exhibiting unstable walking with increased gait variability. Effects of rhythmic sensory stimulation on unstable gait of patients with chronic stroke are unclear. This study aims to determine the effects of rhythmic sensory stimulation on the gait of patients with chronic stroke. Twenty older adults with stroke and twenty age- and gender-matched healthy controls walked 60 m under four conditions: normal walking with no stimulation, walking with rhythmic auditory stimulation (RAS) through an earphone in the ear, walking with rhythmic somatosensory stimulation (RSS) through a haptic device on the wrist of each participant, and walking with rhythmic combined stimulation (RCS: RAS + RSS). Gait performance in the stroke group significantly improved during walking with RAS, RSS, and RCS compared to that during normal walking (p < 0.008). Gait variability significantly decreased under the RAS, RSS, and RCS conditions compared to that during normal walking (p < 0.008). Rhythmic sensory stimulation is effective in improving the gait of patients with chronic stroke, regardless of the type of rhythmic stimuli, compared to healthy controls. The effect was greater in patients with reduced mobility, assessed by the Rivermead Mobility Index (RMI).

The effects of different frequencies of rhythmic acoustic stimulation on gait stability in healthy elderly individuals: a pilot study

The efficacy of rhythmic acoustic stimulation (RAS) to improve gait and balance in healthy elderly individuals is controversial. Our aim was to investigate, through 3D gait analysis, the effect of different types of RAS (fixed frequency and based on subject-specific cadence), using conventional gait parameters and the trunk displacement as readouts. Walking at a fixed frequency of 80 bpm, the subjects showed extended duration of gait cycle and increased gait variability while the same individuals, walking at a fixed frequency of 120 bpm, showed reduced trunk sway and gait cycle duration. With regard to the RAS at subject-specific frequencies, walking at 90% of the subject-specific average cadence did not significantly modify the gait parameters, except for the speed, which was reduced. In contrast, walking at 100% and 110% of the mean cadence caused increased stride length and a slight reduction of temporal parameters and trunk sway. In conclusion, this pilot study shows that using RAS at fixed frequencies might be an inappropriate strategy, as it is not adjusted to individual gait characteristics. On the other hand, RAS frequencies equal to or slightly higher than each subject's natural cadence seem to be beneficial for gait and stability.

Adapting Footfall Rhythmicity to Auditory Perturbations Affects Resilience of Locomotor Behavior: A Proof-of-Concept Study

For humans, the ability to effectively adapt footfall rhythm to perturbations is critical for stable locomotion. However, only limited information exists regarding how dynamic stability changes when individuals modify their footfall rhythm. In this study, we recorded 3D kinematic activity from 20 participants (13 males, 18–30 years old) during walking on a treadmill while synchronizing with an auditory metronome sequence individualized to their baseline walking characteristics. The sequence then included unexpected temporal perturbations in the beat intervals with the subjects required to adapt their footfall rhythm accordingly. Building on a novel approach to quantify resilience of locomotor behavior, this study found that, in response to auditory perturbation, the mean center of mass (COM) recovery time across all participants who showed deviation from steady state (N = 15) was 7.4 (8.9) s. Importantly, recovery of footfall synchronization with the metronome beats after perturbation was achieved prior (+3.4 [95.0% CI +0.1, +9.5] s) to the recovery of COM kinematics. These results highlight the scale of temporal adaptation to perturbations and provide implications for understanding regulation of rhythm and balance. Thus, our study extends the sensorimotor synchronization paradigm to include analysis of COM recovery time toward improving our understanding of an individual’s resilience to perturbations and potentially also their fall risk.

Attention Enhancement for Exoskeleton-Assisted Hand Rehabilitation Using Fingertip Haptic Stimulation

Active enrollment in rehabilitation training yields better treatment outcomes. This paper introduces an exoskeleton-assisted hand rehabilitation system. It is the first attempt to combine fingertip cutaneous haptic stimulation with exoskeleton-assisted hand rehabilitation for training participation enhancement. For the first time, soft material 3D printing techniques are adopted to make soft pneumatic fingertip haptic feedback actuators to achieve cheaper and faster iterations of prototype designs with consistent quality. The fingertip haptic stimulation is synchronized with the motion of our hand exoskeleton. The contact force of the fingertips resulted from a virtual interaction with a glass of water was based on data collected from normal hand motions to grasp a glass of water. System characterization experiments were conducted and exoskeleton-assisted hand motion with and without the fingertip cutaneous haptic stimulation were compared in an experiment involving healthy human subjects. Users' attention levels were monitored in the motion control process using a Brainlink EEG-recording device and software. The results of characterization experiments show that our created haptic actuators are lightweight (6.8 ± 0.23 g each with a PLA fixture and Velcro) and their performance is consistent and stable with small hysteresis. The user study experimental results show that participants had significantly higher attention levels with additional haptic stimulations compared to when only the exoskeleton was deployed; heavier stimulated grasping weight (a 300 g glass) was associated with significantly higher attention levels of the participants compared to when lighter stimulated grasping weight (a 150 g glass) was applied. We conclude that haptic stimulations increase the involvement level of human subjects during exoskeleton-assisted hand exercises. Potentially, the proposed exoskeleton-assisted hand rehabilitation with fingertip stimulation may better attract user's attention during treatment.

Studying the functional connectivity of the primary motor cortex with the binarized cross recurrence plot: The influence of Parkinson's disease

Two new recurrence plot methods (the binary recurrence plot and binary cross recurrence plot) were introduced here to study the long-term dynamic of the primary motor cortex and its interaction with the primary somatosensory cortex, the anterior motor thalamus of the basal ganglia motor loop and the precuneous nucleus of the default mode network. These recurrence plot methods: 1. identify short-term transient interactions; 2. identify long-lasting delayed interactions that are common in complex systems; 3. work with non-stationary blood oxygen level dependent (BOLD) data; 4. may study the relationship of centers with non-linear functional interactions; 5 may compare different experimental groups performing different tasks. These methods were applied to BOLD time-series obtained in 20 control subjects and 20 Parkinson´s patients during the execution of motor activity and body posture tasks (task-block design). The binary recurrence plot showed the task-block BOLD response normally observed in the primary motor cortex with functional magnetic resonance imaging methods, but also shorter and longer BOLD-fluctuations than the task-block and which provided information about the long-term dynamic of this center. The binary cross recurrence plot showed short-lasting and long-lasting functional interactions between the primary motor cortex and the primary somatosensory cortex, anterior motor thalamus and precuneous nucleus, interactions which changed with the resting and motor tasks. Most of the interactions found in healthy controls were disrupted in Parkinson's patients, and may be at the basis of some of the motor disorders and side-effects of dopaminergic drugs commonly observed in these patients.

Effects of a Music-Based Rhythmic Auditory Stimulation on Gait and Balance in Subacute Stroke

Gait and balance impairments are common after stroke. This study aimed to evaluate the effect of a music-based rhythmic auditory stimulation (RAS) in combination with conventional physiotherapy on gait parameters and walking ability in subacute stroke. This single-blind, historical controlled trial, included 55 patients who had suffered a stroke within the three weeks prior to enrolment. Patients from 2018 (n = 27) were assigned as the historical control group whereas 2019 patients (n = 28) received music-based RAS three times a week. Both groups received 11 h of conventional physiotherapy per week during hospitalization. Primary outcomes were gait and balance parameters (Tinetti test and Timed Up&Go test) and walking ability (Functional Ambulation Category scale). Secondary outcomes were trunk control, assistive devices, functional independence (Functional Independence Measure, Barthel index), and stroke severity and disability (modified Rankin scale, National Institutes of Health Stroke Scale). Results: No between-group differences were identified for gait and balance parameters nor for secondary outcomes. Significant between-group differences were observed in the Functional Ambulation Category: the intervention group (Δmean ± SD; 3.43 ± 1.17) showed greater improvement (p = 0.002) than the control group (Δmean ± SD; 2.48 ± 1.09). Compared with conventional physiotherapy alone, our results suggest that the walking ability of subacute stroke patients might be improved with music-based RAS combined with conventional physiotherapy, but this treatment is not more effective than conventional physiotherapy in obtaining gait and balance gains.

Effect of Short-Term Metro-Rhythmic Stimulations on Gait Variability

The aim of the study was to define the effect of different short-term metro-rhythmic stimulations on the time and spatial parameters of gait. The secondary goal was to test whether prior instructions on how to respond to stimulations played a significant role in the stimulation by sound stimuli. Experimental tests of gait were conducted on a group of 36 healthy participants: group 1—subjects who were not informed how to react after hearing sound stimuli, group 2—subjects who received a clear instruction before the test to adjust the frequency of taking steps to the rhythm of the music. The gait research was carried out on a Zebris FDM-S (zebris Medical Gmbh, Isny, Germany) treadmill for various sound stimuli (arrhythmic stimulus, rhythmic stimuli at different rate). It was shown that a short-term influence of metro-rhythmic stimulations changes the time and spatial parameters of gait, i.e., gait frequency, length and duration of the gait cycle. The greatest impact on the modification of the time–space parameters of walking is exerted by rhythmic stimuli at a pace different from the frequency of gait at a preferred velocity. Providing information on how to respond to sounds heard may be important in gait therapy with RAS (rhythmic auditory stimulation).

Increased Symmetry of Lower-Limb Amputees Walking With Concurrent Bilateral Vibrotactile Feedback

Gait asymmetry in lower-limb amputees can lead to several secondary conditions that can decrease general health and quality of life. Including augmented sensory feedback in rehabilitation programs can effectively mitigate spatiotemporal gait irregularities. Such benefits can be obtained with non-invasive haptic systems representing an advantageous choice for usability in overground training and every-day life. In this study, we tested a wearable tactile feedback device delivering short-lasting (100ms) vibrations around the waist syncronized to gait events, to improve the temporal gait symmetry of lower-limb amputees. Three above-knee amputees participated in the study. The device provided bilateral stimulations during a training program that involved ground-level gait training. After three training sessions, participants showed higher temporal symmetry when walking with the haptic feedback in comparison to their natural walking (resulting symmetry index increases of +2.8% for Subject IDA, +12.7% for Subject IDB and +2.9% for Subject IDC). One subject retained improved symmetry (Subject IDB,+14.9%) even when walking without the device. Gait analyses revealed that higher temporal symmetry may lead to concurrent compensation strategies in the trunk and pelvis. Overall, the results of this pilot study confirm the potential utility of sensory feedback devices to positively influence gait parameters when used in supervised settings. Future studies shall clarify more precisely the training modalities and the targets of rehabilitation programs with such devices.

A Novel Wearable Device for Motor Recovery of Hand Function in Chronic Stroke Survivors

Background. In monkey, reticulospinal connections to hand and forearm muscles are spontaneously strengthened following corticospinal lesions, likely contributing to recovery of function. In healthy humans, pairing auditory clicks with electrical stimulation of a muscle induces plastic changes in motor pathways (probably including the reticulospinal tract), with features reminiscent of spike-timing dependent plasticity. In this study, we tested whether pairing clicks with muscle stimulation could improve hand function in chronic stroke survivors. Methods. Clicks were delivered via a miniature earpiece; transcutaneous electrical stimuli at motor threshold targeted forearm extensor muscles. A wearable electronic device (WD) allowed patients to receive stimulation at home while performing normal daily activities. A total of 95 patients >6 months poststroke were randomized to 3 groups: WD with shock paired 12 ms before click; WD with clicks and shocks delivered independently; standard care. Those allocated to the device used it for at least 4 h/d, every day for 4 weeks. Upper-limb function was assessed at baseline and weeks 2, 4, and 8 using the Action Research Arm Test (ARAT), which has 4 subdomains (Grasp, Grip, Pinch, and Gross). Results. Severity across the 3 groups was comparable at baseline. Only the paired stimulation group showed significant improvement in total ARAT (median baseline: 7.5; week 8: 11.5; P = .019) and the Grasp subscore (median baseline: 1; week 8: 4; P = .004). Conclusion. A wearable device delivering paired clicks and shocks over 4 weeks can produce a small but significant improvement in upper-limb function in stroke survivors.

Rehabilitative devices for a top-down approach

INTRODUCTION

In recent years, neurorehabilitation has moved from a 'bottom-up' to a 'top down' approach. This change has also involved the technological devices developed for motor and cognitive rehabilitation. It implies that during a task or during therapeutic exercises, new 'top-down' approaches are being used to stimulate the brain in a more direct way to elicit plasticity-mediated motor re-learning. This is opposed to 'Bottom up' approaches, which act at the physical level and attempt to bring about changes at the level of the central neural system.

AREAS COVERED

In the present unsystematic review, we present the most promising innovative technological devices that can effectively support rehabilitation based on a top-down approach, according to the most recent neuroscientific and neurocognitive findings. In particular, we explore if and how the use of new technological devices comprising serious exergames, virtual reality, robots, brain computer interfaces, rhythmic music and biofeedback devices might provide a top-down based approach.

EXPERT COMMENTARY

Motor and cognitive systems are strongly harnessed in humans and thus cannot be separated in neurorehabilitation. Recently developed technologies in motor-cognitive rehabilitation might have a greater positive effect than conventional therapies.