Balance, Lateropulsion, and Gait Disorders in Subacute Stroke

Association between the balance recovery and the independence after a severe stroke

OBJECTIVES

Research is lacking on the recovery of subjects who have suffered a stroke and have severely impaired balance in the subacute stage. This study aims to analyze the association between balance recovery during inpatient rehabilitation and the level of independence in activities of daily living at discharge in severe subacute stroke patients. Secondarily, it aims to analyze the association between balance at the admission of inpatient rehabilitation after stroke and the level of independence in activities of daily living at discharge in the same sample.

METHODS

A longitudinal retrospective observational cohort study was conducted. Subacute post-stroke patients who could not stand at admission were included (n = 80). A correlation analysis was undertaken. The Functional Independence Measure was used to evaluate activities of daily living performance and the Berg Balance Scale to assess balance.

RESULTS

Correlation between balance recovery during inpatient rehabilitation and the level of independence at discharge: Spearman's rho = 0.741 (p < 0.001). Correlation between the Balance at admission and the level of independence at discharge: Spearman's rho = 0.288 (p = 0.009).

DISCUSSION

Monitoring balance recovery after a severe stroke may be necessary to establish functional goals during inpatient rehabilitation. Low functional independence at discharge from inpatient rehabilitation post stroke cannot always be expected in subjects with severe balance impairment at admission.

Effects of 3 Cycles of Increasing Botulinum Toxin Doses on Functional Parameters of Post-stroke Spastic Gait: A Prospective Cohort Study

BackgroundSingle botulinum toxin type A (BT-A) injections reduce spasticity, but the effects of repeated injections on walking activities remain unclear.ObjectivesTo demonstrate cumulative effectiveness of progressively higher doses of BT-A on walking activities (primary outcome) and spasticity reduction.Methods32 individuals with lower-limb spasticity impairing gait post-stroke were included in this prospective cohort study. Participants received 3 injections of increasing doses of Inco BT-A (400-600-800 U) in both upper and lower limbs and were followed for 7 months. Activity evaluations included the 10 MWT, 6MWT, TUG, and a timed stairs test (TST). Spasticity was assessed using the Modified Ashworth (MAS) and Modified Tardieu (MTS) scales.ResultsActivities remained stable after the 1st injection but improved after the 2nd and 3rd cycles on the 6MWT (+0.07 and +0.12 m/s, respectively, p < 0.05) and TST (-13.7 s and -14.8 s, respectively, p < 0.05). Spasticity significantly reduced after each injection cycle, with greater reductions after the 2nd and 3rd cycles.ConclusionsRepeated, progressively higher doses of Inco BT-A in lower-limb spasticity post-stroke improved walking activities and reduced spasticity, more so after successive cycles and higher doses. This could suggest cumulative effects, better effects due to higher doses, or both. This supports the use of progressively higher doses to thoroughly treat spasticity patterns.clinicaltrials.gov : NCT04544280.

Writing and drawing tilts after right hemisphere stroke are signs of a wrong verticality representation

BACKGROUND

Many signs of spatial dysgraphia and drawing errors after right hemispheric stroke (RHS) have been attributed to spatial neglect or impaired sensory feedback. Counterclockwise (contralesional) tilts of graphomotor productions remained to be explained.

OBJECTIVE

To test whether graphomotor tilts stem from a tilted representation of verticality transposed to the top/bottom axis of the sheet of paper, using data from the DOBRAS cohort.

METHODS

Handwriting and drawing orientations were measured from the writing of 3 lines and the drawing of the Gainotti Figure (house roof lines). Verticality perception was measured with the visual (VV) and postural (PV) verticals. Severity of extra-body (EBN) and body (BN) neglect were each quantified with composite scores (battery of 8 tests).

RESULTS

We analyzed data from 133 individuals: 64 healthy individuals (median [Q1; Q3] age 63 [59; 71] years) and 69 in the subacute phase after RHS (median age 68 [62; 73] years). With respect to normal cut-offs (writing -5.4°; drawing -8.1°), 26/69 (38 %) individuals with RHS showed at least one graphomotor tilt (median [IQR] writing tilt:6.8° [-9.7; -1.7]; drawing tilt:10.9° [-17.6; -6.4]). Compared to individuals without graphomotor tilts, those with both writing and drawing tilts showed greater contralesional tilts in verticality perception (VV:1.4° [-4; 0.6] vs -7.9° [-11.5; - 7.5]; PV:1° [-2.4; 0.2] vs -8° [-9; -5.4], P-values ≤0.001) and more severe spatial neglect (EBN: 4.2 [1.8; 9.3] vs 16.6 [10.2; 20.4]; BN: 22.7 [17; 28.2] vs 37.8 [35.9; 39.7], P-values ≤0.001). Composite graphomotor z-scores for writing and drawing correlated with verticality estimates (VV+PV, rs =0.46, P < 10-4) and spatial neglect scores (EBN+BN, rs = -0.36, P < 0.01).

CONCLUSION

Contralesional tilts of writing and drawing after RHS are primarily related to a tilted representation of verticality and secondarily to spatial neglect. They are easy to detect and could be considered a first step to perform early, before conventional tests of verticality perception.

REGISTRATION

ClinicalTrials.gov: NCT03203109.

Subclinical brain manifestations of repeated mild traumatic brain injury are changed by chronic exposure to sleep loss, caffeine, and sleep aids

INTRODUCTION

After mild traumatic brain injury (mTBI), the brain is labile for weeks and months and vulnerable to repeated concussions. During this time, patients are exposed to everyday circumstances that, in themselves, affect brain metabolism and blood flow and neural processing. How commonplace activities interact with the injured brain is unknown. The present study in an animal model investigated the extent to which three commonly experienced exposures-daily caffeine usage, chronic sleep loss, and chronic sleep aid medication-affect the injured brain in the chronic phase.

METHODS

Subclinical trauma by repeated mTBIs was produced by our head rotational acceleration injury model, which causes brain injury consistent with the mechanism of concussion in humans. Forty-eight hours after a third mTBI, chronic administrations of caffeine, sleep restriction, or zolpidem (sedative hypnotic) began and were continued for 70 days. On Days 30 and 60 post injury, resting state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) were performed.

RESULTS

Chronic caffeine, sleep restriction, and zolpidem each changed the subclinical brain characteristics of mTBI at both 30 and 60 days post injury, detected by different MRI modalities. Each treatment caused microstructural alterations in DTI metrics in the insular cortex and retrosplenial cortex compared with mTBI, but also uniquely affected other gray and white matter regions. Zolpidem administration affected the largest number of individual structures in mTBI at both 30 and 60 days, and not necessarily toward normalization (sham treatment). Chronic sleep restriction changed local functional connectivity at 30 days in diametrical opposition to chronic caffeine ingestion, and both treatment outcomes were different from sham, mTBI-only and zolpidem comparisons. The results indicate that commonly encountered exposures modify subclinical brain activity and structure long after healing is expected to be complete.

CONCLUSIONS

Changes in activity and structure detected by fMRI are widely understood to reflect changes in the functions of the affected region which conceivably underlie mTBI neuropathology and symptomatology in the chronic phase after injury.

Evaluation of Smartphone Technology on Spatiotemporal Gait in Older and Diseased Adult Populations

Objective: Advancements in smartphone technology provide availability to evaluate movement in a more practical and feasible manner, improving clinicians' ability to diagnose and treat adults at risk for mobility loss. The purpose of this study was to evaluate the validity and reliability of a smartphone application to measure spatiotemporal outcomes during level (primary) and uphill/downhill (secondary) walking with and without an assistive device for older adults (OAs), Parkinson's Disease (PD) and cerebrovascular accident (CVA) populations. Methods: A total of 50 adults (OA = 20; PD = 15; CVA = 15) underwent gait analysis at self-selected gait speeds under 0-degree, 5-degree uphill and 5-degree downhill environments. The validity and reliability of the smartphone outcomes were compared to a motion-capture laboratory. Bland-Altman analysis was used to evaluate limits of agreement between the two systems. Intraclass correlation coefficients (ICCs) were used to determine absolute agreement, and Pearson correlation coefficients (r) were used to assess the strength of the association between the two systems. Results: For level walking, Bland-Altman analysis revealed relatively equal estimations of spatiotemporal outcomes between systems for OAs without an assistive device and slight to mild under- and overestimations of outcomes between systems for PD and CVA with and without an assistive device. Moderate to very high correlations between systems (without an assistive device: OA r-range, 0.72-0.99; PD r-range, 0.87-0.97; CVA r-range, 0.56-0.99; with an assistive device: PD r-range, 0.35-0.98; CVA r-range, 0.50-0.99) were also observed. Poor to excellent ICCs for reliability between systems (without an assistive device: OA ICC range, 0.71-0.99; PD ICC range, 0.73-0.97; CVA ICC range, 0.56-0.99; with an assistive device: PD ICC range, 0.22-0.98; CVA ICC range, 0.44-0.99) were observed across all outcomes. Conclusions: This smartphone application can be clinically useful in detecting most spatiotemporal outcomes in various walking environments for older and diseased adults at risk for mobility loss.

Analyses of weight-bearing asymmetry pattern for standing in the early phase after stroke: a cross-sectional study

BACKGROUND

How the weight-bearing asymmetry pattern and related maximum lateral weight-bearing capacity, physical functions, balance, and mobility involved in weight-bearing asymmetry and lesions are related to weight-bearing asymmetry in patients with early-onset stroke remains unclear.

OBJECTIVE

To investigate the difference between weight-bearing in the early phase after stroke categorized as symmetrical or nonsymmetrical regarding impairments, balance, walking, and independence, and any lesion location difference.

METHODS

This cross-sectional study included 46 persons with hemiparetic stroke within 3 weeks from onset undergoing inpatient rehabilitation and classified into symmetrical, paretic, and non-paretic groups. We performed posturographic, functional, mobility, and lesion location assessments on participants once the evaluation was possible.

RESULTS

The symmetrical, paretic, and non-paretic groups included 14, 11, and 21 patients, respectively. The non-paretic group had lesser mean % body weight in maximum lateral weight-bearing to the paretic direction (79% versus 55%, p < .001), motor function of the hip lower limb (64 versus 58, p = .003) per the Stroke Impairment Assessment Set, Trunk Impairment Scale (18 versus 15, p = .020), and Berg Balance Scale (42 versus 32, p = .047) than the paretic group with more lesions in the insula (55% versus 0%, p < .001) and parietal cortex (36% versus 0%, p = .009) than the non-paretic group.

CONCLUSION

The non-paretic group had low dynamic balance, severe motor paresis, and trunk dysfunction. The paretic group had lesions in the insula or parietal cortex.

Post-stroke rehabilitation in the peri-pandemic COVID-19 era

The coronavirus disease 2019 (COVID-19), which arose in late 2019, caused extensive destruction, impacting a substantial proportion of the worldwide population and leading to millions of deaths. Although COVID-19 is mainly linked to respiratory and pulmonary complications, it has the potential to affect neurologic structures as well. Neurological involvement may manifest as minimal and reversible; however, a notable proportion of cases have exhibited pronounced neurological consequences, such as strokes. Endothelial inflammation, hypercoagulation, renin-angiotensin-aldosterone system alterations, and cardiogenic embolism are the pathophysiological mechanisms of stroke under COVID-19 circumstances. Physical activity and exercise have improved several aspects of post-stroke recovery, including cardiovascular health, walking capacity, and upper limb strength. They are commonly used to assist stroke survivors in overcoming their motor restrictions. Furthermore, stroke rehabilitation can incorporate a range of specific techniques, including body-weight-supported treadmill applications, constraint-induced movement therapy, robotic rehabilitation interventions, transcranial direct current stimulation, transcranial magnetic stimulation, and prism adaptation training. Under pandemic conditions, there were several barriers to neurological rehabilitation. The most significant of these were individual's fear of infection, which caused them to postpone their rehabilitation applications and rehabilitation areas being converted into COVID-19 units. The primary emphasis had turned to COVID-19 treatment. Several valuable data and views were gained in reorganizing rehabilitation during the pandemic, contributing to establishing future views in this regard.

Robotic gait training and botulinum toxin injection improve gait in the chronic post-stroke phase: A randomized controlled trial

BACKGROUND

Improving walking ability is one of the main goals of rehabilitation after stroke. When lower limb spasticity increases walking difficulty, botulinum toxin type A (BTx-A) injections can be combined with non-pharmacologic interventions such as intensive rehabilitation using a robotic approach. To the best of our knowledge, no comparisons have been made between the efficacy of robotic gait training and conventional physical therapy in combination with BTx-A injections.

OBJECTIVE

To conduct a randomized controlled trial to compare the efficacy on gait of robotic gait training versus conventional physiotherapy after BTx-A injection into the spastic triceps surae in people after stroke.

METHOD

Thirty-three participants in the chronic stroke phase with triceps surae spasticity inducing gait impairment were included. After BTx-A injection, participants were randomized into 2 groups. Group A underwent robotic gait training (Lokomat®) for 2 weeks, followed by conventional physiotherapy for 2 weeks (n = 15) and Group B underwent the same treatment in reverse order (n = 18). The efficacy of these methods was tested using the 6-minute walk test (6MWT), comparing post-test 1 and post-test 2 with the pre-test.

RESULTS

After the first period, the 6MWT increased significantly more in Group A than in Group B: the mean difference between the interventions was 33 m (95%CI 9; 58 p = 0.007; g = 0.95), in favor of Group A; after the second period, the 6MWT increased in both groups, but the 30 m difference between the groups still remained (95%CI 5; 55 p = 0.019; g = 0.73).

CONCLUSION

Two weeks of robotic gait training performed 2 weeks after BTx-A injections improved walking performance more than conventional physiotherapy. Large-scale studies are now required on the timing of robotic rehabilitation after BTx-A injection.

Improving orientation with respect to gravity enhances balance and gait recovery after stroke: DOBRAS cohort

BACKGROUND

Lateropulsion is a deficit in body orientation with respect to gravity, frequent after stroke. Although it is a primary factor affecting mobility, the impact of its attenuation on balance and gait recovery has never been investigated. Moreover, most studies on the lateropulsion time-course focus on severe forms suspected to have a poor recovery, which is not proven.

OBJECTIVES

To investigate lateropulsion attenuation and test 2 hypotheses: 1) lateropulsion attenuation greatly contributes to balance and gait recovery and 2) severe forms of lateropulsion recover slower than moderate forms.

METHODS

This longitudinal study involved individuals included in the Determinants of Balance Recovery After Stroke (DOBRAS) cohort, after a first-ever hemispheric stroke, with data collected on day 30 (D30), D60 and D90 post-stroke. Body orientation with respect to gravity was assessed using the Scale for Contraversive Pushing (both scores and severity grouping), in parallel with balance (Postural Assessment Scale for Stroke) and gait (modified Fugl-Meyer Gait Assessment).

RESULTS

Among the 106 eligible individuals (mean age 66.5 [SD 9.7] years), on D30, 43 (41%) were considered upright and 63 (59%) showed lateropulsion: 30 (28%) moderate and 33 (31%) severe. Most individuals with lateropulsion (73%) improved their body orientation, progressing from severe to moderate lateropulsion, or becoming upright. However, half were still not upright on D90. The improvement in body orientation had a large impact on mobility, especially in individuals with severe lateropulsion, in whom it explained about 50% of balance and gait recovery between D30 and D60, then 20% (D60-D90). For moderate lateropulsion, its attenuation explained about 20% of balance and gait recovery until D90. Lateropulsion attenuation was not slower in individuals with severe forms.

CONCLUSIONS

Lateropulsion attenuation enhances balance and gait recovery in individuals after stroke suggesting that specific rehabilitation of body orientation with respect to gravity might help to recover mobility.

REGISTRATION

NCT03203109.

A comparative study on the overlapping effects of clinically applicable therapeutic interventions in patients with central nervous system damage

This study was conducted to investigate the effects of anti-gravity treadmill (AGT) training, which provides visual feedback and Biorescue training on proprioception, muscle strength, balance, and gait, in stroke patients. A total of 45 people diagnosed with post-stroke were included as study subjects; they were randomized to an AGT training group provided with visual feedback (Group A), a Biorescue training group provided with visual feedback (Group B), and an AGT/Biorescue group that subsequently received AGT training and Biorescue training (Group C). A muscle strength-measuring device was used to evaluate muscle strength. Timed Up and Go and Bug Balance Scale assessment sheets were used to evaluate balance ability. Dartfish software was used to evaluate gait ability. The results of the study showed that Groups A and C had a significant increase in muscle strength compared with Group B; in terms of balance and gait abilities, Group C showed a significant increase in balance ability and gait speed and a significant change in knee joint angle compared with Groups A and B. In conclusion, this study suggests that including a method that applies multiple therapeutic interventions is desirable in the rehabilitation of stroke patients to improve their independence.

Immediate Effect of Ankle Exoskeleton on Spatiotemporal Parameters and Center of Pressure Trajectory After Stroke

Gait impairments is a common condition in post-stroke subjects. We recently presented a wearable ankle exoskeleton called G-Exos, which showed that the device assisted in the ankle's dorsiflexion and inversion/reversion movements. The aim of the current pilot study was to explore spatiotemporal gait parameters and center of pressure trajectories associated with the use of the G-Exos in stroke participants. Three post-stroke subjects (52-63 years, 2 female/1 male) walked 160-meter using the G-Exos on the affected limb, on a protocol divided into 4 blocks of 40-meters: (I) without the exoskeleton, (II) with systems hybrid system, (III) active only and (IV) passive only. The results showed that the use of the exoskeleton improved swing and stance phases on both limbs, reduced stride width on the paretic limb, increased stance COP distances, and made single support COP distances more similar between the paretic and non-paretic limb. This suggests that all G-Exos systems contributed to improving body weight bearing on the paretic limb and symmetry in the gait cycle.

Development of split-force-controlled body weight support (SF-BWS) robot for gait rehabilitation

This study introduces a body-weight-support (BWS) robot actuated by two pneumatic artificial muscles (PAMs). Conventional BWS devices typically use springs or a single actuator, whereas our robot has a split force-controlled BWS (SF-BWS), in which two force-controlled actuators independently support the left and right sides of the user's body. To reduce the experience of weight, vertical unweighting support forces are transferred directly to the user's left and right hips through a newly designed harness with an open space around the shoulder and upper chest area to allow freedom of movement. A motion capture evaluation with three healthy participants confirmed that the proposed harness does not impede upper-body motion during laterally identical force-controlled partial BWS walking, which is quantitatively similar to natural walking. To evaluate our SF-BWS robot, we performed a force-tracking and split-force control task using different simulated load weight setups (40, 50, and 60 kg masses). The split-force control task, providing independent force references to each PAM and conducted with a 60 kg mass and a test bench, demonstrates that our SF-BWS robot is capable of shifting human body weight in the mediolateral direction. The SF-BWS robot successfully controlled the two PAMs to generate the desired vertical support forces.

EEG Based Cortico-Muscular Connectivity During Standing Early Post Stroke

In this exploratory study we studied brain activation and corticomuscular connectivity during standing in healthy individuals and persons with stroke within 40 days of cerebrovascular accident (CVA). EEG and EMG data were acquired during standing and analysis showed a trend of higher EEG power (hyper activation) in the stroke group. Direct corticomuscular connectivity between sensorimotor cortices and contralateral lower extremity muscles showed lower connectivity between affected motor, premotor, and sensory cortices, and contralateral lower extremity peripheral muscles with moderate effect size. The preliminary data in this paper suggest re-organization in left sensorimotor cortex role in controlling contralateral lower extremity muscles during standing. Correlational analysis in stroke group within 40 days of CVA showed a relationship between higher corticomuscular connectivity and better scores on balance assessments.Clinical Relevance- This study evaluates corticomuscular connectivity during standing in healthy controls and individuals with subacute stroke (within 40 days of injury). Better understanding of cortical control of standing post stroke is important to improve strategies used in mobility rehabilitation.

Clinimetric properties of relevant criteria for assessing writing and drawing orientation after right hemisphere stroke

BACKGROUND

Writing and drawing orientation is rarely assessed in clinical routine, although it might have a potential value in detecting impaired verticality perception after right hemispheric stroke (RHS). Assessment tools and criteria must be conceived and validated. We therefore explored the clinimetric properties of a set of quantitative writing and drawing orientation criteria, their ranges of normality, and their tilt prevalence in RHS individuals.

NEW METHODS

We asked 69 individuals with subacute RHS and 64 matched healthy controls to write three lines and to copy the Gainotti Figure (house and trees). We determined six criteria referring to the orientation of writing and drawing main axes: for writing, the line and margin orientations, and for drawing, the tree, groundline, wall, and roofline orientations. Orientations were measured by using an electronic protractor from specific landmarks positioned by independent evaluators.

RESULTS

The set of criteria fulfilling all clinimetric properties (feasibility, measurability, reliability) comprised the line orientation of the writing and the wall and roofline orientations of the drawing. Writing and drawing tilts were frequent after RHS (about 30% by criterion).

COMPARISON WITH EXISTING METHODS

So far, graphomotor orientation was mostly tested qualitatively and could not be objectively appreciated in absence of validated tools and criteria, and without ranges of normality. Writing and drawing tilts may now be assessed both in routine clinical practice and research.

CONCLUSIONS

Our study paves the way for investigating the clinical determinants of graphomotor tilts, including impaired verticality perception, to better understand their underlying mechanisms.

Dynamic changes of the direction and angle of radiographic ocular lateral deviation in patients with lateropulsion after stroke onset

OBJECTIVE

To examine if radiographic ocular lateral deviation (rOLD) could be provoked in stroke patients with mild-to-moderate lateropulsion according to vertical perception.

METHODS

In this single-center, retrospective study, acute stroke patients with mild-to-moderate lateropulsion assessed by the Scale for Contraversive Pushing were enrolled. Computed tomography or magnetic resonance imaging was performed on all patients on admission and then according to their conditions. The direction and angle of rOLD were compared among three groups according to the responsible lesion: lateral medullary (LM), pontine (P), and hemispheric (H).

RESULTS

Sixty-six patients (male, 47; average age, 67 years) were enrolled and divided into the LM (n = 37), P (n = 8), and H (n = 21) groups. All patients had body tilt. Patients in the LM group showed body tilt to the ipsilesional side during hospitalization, while those in the P and H groups tilted to the contralesional side. All patients had rOLD at the final assessment at an average of 13 days after onset; patients in the P and H groups showed contralateral rOLD, while those in the LM group showed ipsilateral rOLD if they did not have cerebellar or pontine lesions. Significant decreases in the angle and changes in direction of rOLD according to lesion site were observed during hospitalization.

CONCLUSION

Serial changes in rOLD findings after stroke onset are different according to the responsible lesion. The direction of rOLD in most patients is in accordance with vertical perception after the acute stage of stroke.

Determining an optimal posturography dataset to identify standing behaviors in the post-stroke subacute phase. Cross-sectional study

BACKGROUND

A key issue for posturography is the expression of robust results, in a simplified way. Most studies of individuals post-stroke concern the chronic phase, with small sample sizes.

OBJECTIVES

By reducing the number of posturographic indices, we aimed to determine an optimal dataset and understand typical postural behaviors in the subacute post-stroke phase.

METHODS

In this cross-sectional study ancillary to the DOBRAS cohort, individuals were assessed as soon they could complete a full posturography session (with and without vision) after a first hemispheric stroke. Body-weight distribution on the mediolateral (ML) axis, position of the center of pressure on the antero-posterior (AP) axis, and postural sway on both axes were computed. Balance ability in daily life was quantified with the Postural Assessment Scale for Stroke. Data were analyzed by principal component and hierarchical clustering analyses as well as multiple linear regression.

RESULTS

We enrolled 95 individuals (median age: 67.0 years [Q1; Q3 56.0; 72.0]; 68% males). Vision suppression had a marginal effect, only increasing postural sway. Regardless of the visual condition, posturographic behavior was captured by a set of 3 indices that explained almost all the information. One postural sway index (ML or AP) gave more information (48%) than both position indices (ML 26% and AP 15%). These 3 indices identified 3 standing behaviors: 1) stable and symmetric, 2) asymmetric, unstable, and positioned backward, and 3) very unstable and positioned forward. Balance ability in daily life was explained (49% of the information, 95%CI [35; 63]) by weight-bearing asymmetry and postural sway on the ML axis, which played an independent role (both p<10-5), with similar impact.

CONCLUSIONS

Three typical behaviors allow standing after stroke: described by only 3 posturographic indices. Weight-bearing asymmetry is not the primary parameter and should not be considered in isolation as an outcome. To increase the feasibility of posturography in the early subacute phase and to simplify evaluation sessions, trials could be limited to eyes open.

REGISTRATION

NCT03203109.

Phase-Dependent Modulation of Muscle Activity and Intermuscular Coupling During Walking in Patients After Stroke

Many patients experience motor and sensory impairments after stroke, leading to gait disturbances. Analysis of muscle modulation mode during walking can provide evidence for neurological changes after stroke, while how stroke affects individual muscle activity and muscular coordination in certain gait sub-phases remains unclear. The purpose of the present study is to comprehensively investigate phase-dependent ankle muscle activity and intermuscular coupling patterns in post-stroke patients. In this experiment, 10 post-stroke patients, 10 young healthy subjects and 10 elderly healthy subjects were recruited. All subjects were asked to walk at their preferred speeds on the ground, and surface electromyography (sEMG) and marker trajectory data were collected simultaneously. The gait cycle of each subject was divided into four substages according to the labeled trajectory data. On this basis, fuzzy approximate entropy (fApEn) was used to analyze the complexity of ankle muscle activity during walking. And the transfer entropy (TE) was applied to reflect directed information transmission between ankle muscles. Results found that complexity of ankle muscles activities in patients after stroke showed similar trends to that in healthy subjects. Different from healthy subjects, the complexity of ankle muscle activity in patients with stroke tends to increase in most of the gait sub-phases. While TE values between the ankle muscles in patients with stroke tend to decrease throughout the gait cycle, especially in the second double support stage. Compared with age-matched healthy subjects, patients recruit more motor units throughout their gait while increasing muscle coupling to achieve gait function. The combined application of fApEn and TE provide a more comprehensive understanding of phase-dependent muscle modulation mechanisms in post-stroke patients.

Effect of wearable exoskeleton on post-stroke gait: A systematic review and meta-analysis

BACKGROUND

Wearable exoskeletons are a recently developed technology.

OBJECTIVES

The present systematic review aimed to investigate the effect of a wearable exoskeleton on post-stroke walking by considering its use in a gait training system and simply as an orthosis assisting walking.

METHODS

We systematically searched for randomised and quasi-randomised controlled trials in PubMed, Scopus, CINAHL and Embase databases from their earliest publication record to July 2021. We chose reports of trials investigating the effects of exoskeleton-assisted training or the effects of wearing an exoskeleton to assist walking. A meta-analysis was conducted to explore the benefits of the wearable exoskeleton on mobility capacity, walking speed, motor function, balance, endurance and activities of daily living.

RESULTS

We included 13 studies (492 participants) comparing exoskeleton-assisted training with dose-matched conventional gait training. Studies addressing the effect of wearing a wearable exoskeleton were unavailable. As compared with conventional gait training at the end of the intervention, exoskeleton-assisted training was superior for walking speed (mean difference [MD] 0.13 m/s, 95% CI 0.05; 0.21) and balance (standardized MD [SMD] 0.3, 95% CI 0.07; 0.54). The subgroup with chronic stroke (i.e., > 6 months) presented the outcome favouring exoskeleton-assisted training regarding overall mobility capacity (SMD 0.37, 95% CI 0.04; 0.69). At the end of follow-up, exoskeleton-assisted training was superior to conventional gait training in overall mobility (SMD 0.45, 95% CI 0.07; 0.84) and endurance (MD 46.23 m, 95% CI 9.90; 82.56).

CONCLUSIONS

Exoskeleton-assisted training was superior to dose-matched conventional gait training in several gait-related outcomes at the end of the intervention and follow-up in this systematic review and meta-analysis, which may support the use of exoskeleton-assisted training in the rehabilitation setting. Whether wearing versus not wearing a wearable exoskeleton is beneficial during walking remains unknown.

Spatial neglect encompasses impaired verticality representation after right hemisphere stroke

Spatial neglect after right hemisphere stroke (RHS) was recently found to encompass lateropulsion, a deficit in body orientation with respect to gravity caused by altered brain processing of graviception. By analogy, we hypothesized that spatial neglect after RHS might encompass an altered representation of verticality. We also assumed a strong relation between body neglect and impaired postural vertical, both referring to the body. To tackle these issues, we performed contingency and correlation analyses between two domains of spatial neglect (body, extra-body) and two modalities of verticality perception (postural, visual) in 77 individuals (median age = 67) with a first-ever subacute RHS (1-3 months). All individuals with a transmodal (postural and visual) tilt in verticality perception (n = 26) had spatial neglect, but the reverse was not found. Correlation and multivariate analyses revealed that spatial neglect (and notably body neglect) was associated more with postural than visual vertical tilts. These findings indicate that after RHS, an impaired verticality representation results from a kind of graviceptive neglect, bearing first on somaesthetic graviception and second on vestibular graviception. They also suggest that the human brain uses not only a mosaic of 2D representations but also 3D maps involving a transmodal representation of verticality.

Effects of Dynamic Sitting Exercise with Delayed Visual Feedback in the Early Post-Stroke Phase: A Pilot Double-Blinded Randomized Controlled Trial

Sitting ability in the early post-stroke phase affects functional balance ability and other prognoses. We investigated whether dynamic sitting exercise with delayed visual feedback in the mediolateral and anteroposterior directions affected postural control in the early post-stroke phase. In this pilot randomized controlled trial, 27 hemiparetic stroke patients were randomized to experimental (n = 13) and control (n = 14) groups. Dynamic sitting exercise (30 times/day, 5 days/week) in the mediolateral and anteroposterior directions, with 500-ms-delayed (experimental group) or real-time (control group) visual feedback on a computer, was added to usual physical therapy. We evaluated the postural assessment scale for stroke (PASS), static and dynamic sitting balance tasks, the five-times sit-to-stand test, trunk impairment scale, functional ambulation category, and functional independence measure−motor items. In intention-to-treat analysis, the experimental group demonstrated a significant intervention effect on the PASS score (p < 0.05). The mean percentage of body weight on the moving side in the lateral sitting task and the number of successes in the five-times sit-to-stand test were significantly higher in the experimental group than those in the control group (p < 0.05). Thus, the proposed exercise improves postural control, dynamic sitting balance, and sit-to-stand ability in early post-stroke patients.

Analysis of Verticality Perception in Older Adults With and Without Acute Stroke in Half-Lying Versus Sitting Positions

Currently, there is no research consensus regarding the influence of body position on verticality perception in acute stroke. In this study, we aimed to compare the influence of half-lying and sitting positions on measurements of the subjective visual vertical (SVV) and the subjective haptic vertical (SHV) of individuals in the acute stroke phase. In this cross-sectional study, we compared these positional experiences in two groups of participants: adults in the acute stroke phase and elderly individuals without stroke. Independent variables were stroke versus no-stroke groups, in half-lying versus sitting positions. Analyzed variables of related interest were cognition (Mini-Mental State Examination or MMSE), stroke severity (National Institutes of Health Stroke Scale or NIHSS), and trunk control (Trunk Impairment Scale or TIS). Dependent variables were visual and haptic verticality, as evaluated by SVV and SHV. There were observed differences in absolute SVV in sitting position between groups (p = 0.021), absolute SVV in half-lying position between groups (p = 0.033), absolute SHV in sitting position between groups (p = 0.003), absolute SHV in half-lying position between groups (p = 0.002), and constant SVV in half-lying position between groups (p = 0.007). In the stroke group there was a higher coefficient of variation of SVV and SHV in the half-lying position compared to sitting position. In the sitting position, we observed a very strong correlation between the TIS and absolute SHV (p = 0.008). We concluded that individuals in the acute phase of stroke had greater misperceptions of visual and haptic verticality than older adults without strokes and that individuals in the acute phase of stroke showed less variability in visual and haptic vertical perception in the sitting position than in the half-lying position. By implication, we should encourage the sitting position in the acute stroke phase and develop early strategies to increase the verticality perception.

Lateropulsion Prevalence after Stroke: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Lateropulsion is a deficit of active body orientation with respect to gravity in the frontal plane, mostly observed after a stroke. It magnifies mobility limitations and so represents an emerging target in rehabilitation. Efforts to design specific interventional studies require some basic knowledge of epidemiology, which is insufficient today because many studies focused on a few severe forms in individuals called pushers. The objectives of this study were to bridge this gap.

METHODS

We systematically searched MEDLINE, EMBASE, CINAHL, and Cochrane Clinical Trials up to 31 May 2021 for original research reporting a prevalence or incidence of post-stroke lateropulsion. We followed MOOSE and PRISMA guidelines. Eligibility for inclusion, data extraction, and study quality (Joanna Briggs Institute guidelines) were evaluated by two reviewers who used a standardized protocol: PROSPERO (CRD42020175037). A random-effects meta-analysis was used to obtain the pooled prevalence, whose heterogeneity was investigated by subgroup analysis (stroke locations and post-stroke phases) and meta-regression.

RESULTS

We identified 22 studies (5125 individuals; mean age 68.5 years; 42.6% female; assessed 24 days, on average, after stroke), most published after 2000. The studies' quality was adequate, with only 8 (36.4%) showing risk of bias. The pooled lateropulsion prevalence was 55.1% (95% confidence interval [CI] [35.9-74.2]) and was consistent across assessment tools. After supratentorial stroke, lateropulsion prevalence was 41% (95%CI [33.5-48.5]), and only 12.5% (95%CI [9.2-15.9]) in individuals with severe lateropulsion, called pushers. Meta-regression did not reveal any effect of age, sex, geographic region, publication year, or study quality. Lateropulsion prevalence progressively decreased from 52.8% (95%CI [40.7-65]) in the acute phase to 37% (95%CI [26.3-47.7]) in the early subacute phase and 22.8% (95%CI [0-46.3]) in the late subacute phase. The ratio of right- to left-hemispheric stroke with lateropulsion increased as a function of time: 1.7 in the acute phase to 7.7 in the late subacute phase. After infratentorial stroke, lateropulsion prevalence was very high, reaching 83.2% (95%CI [63.9-100.3]).

CONCLUSIONS

Post-stroke lateropulsion prevalence is high, which appeals for its systematic detection to guide early interventions. Uprightness is predominantly controlled from the right hemisphere.

Pathological Gait Signatures of Post-stroke Dementia With Toe-Off and Heel-to-Ground Angles Discriminate From Alzheimer's Disease

Given the limited power of neuropsychological tests, there is a need for a simple, reliable means, such as gait, to identify mild dementia and its subtypes. However, gait characteristics of patients with post-stroke dementia (PSD) and Alzheimer’s disease (AD) are unclear. We sought to describe their gait signatures and to explore gait parameters distinguishing PSD from post-stroke non-dementia (PSND) and patients with AD. We divided 3-month post-stroke patients into PSND and PSD groups based on the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and the activity of daily living (ADL). Thirty-one patients with AD and thirty-two healthy controls (HCs) were also recruited. Ten gait parameters in one single and two dual-task gait tests (counting-backward or naming-animals while walking) were compared among the groups, with adjustment for baseline demographic covariates and the MMSE score. The area under the receiver operating characteristic curve (AUC) was used to identify parameters discriminating PSD from individuals with PSND and AD. Patients with PSD and patients with AD showed impaired stride length, velocity, stride time, and cadence while patients with PSD had altered stance and swing phase proportions (all p ≤ 0.01, post hoc). Patients with AD had smaller toe-off (ToA) and heel-to-ground angles (HtA) (p ≤ 0.01) than HCs in dual-task gait tests. Individuals with PSD had a shorter stride length, slower velocity, and altered stance and swing phase percentages in all tests (p ≤ 0.01), but a higher coefficient of variation of stride length (CoV_SL) and time (CoV_ST) only in the naming animals-task gait test (p ≤ 0.001) than individuals with PSND. ToA and HtA in the naming animals-task gait test were smaller in individuals with AD than those with PSD (p ≤ 0.01). Statistical significance persisted after adjusting for demographic covariates, but not for MMSE. The pace and the percentage of stance or swing phase in all tests, CoV_ST in the dual-task paradigm, and CoV_SL only in the naming animals-task gait test (moderate accuracy, AUC > 0.700, p ≤ 0.01) could distinguish PSD from PSND. Furthermore, the ToA and HtA in the naming animals-task gait paradigm discriminated AD from PSD (moderate accuracy, AUC > 0.700, p ≤ 0.01). Thus, specific gait characteristics could allow early identification of PSD and may allow non-invasive discrimination between PSD and AD, or even other subtypes of dementia.

Effects of prismatic adaptation on balance and postural disorders in patients with chronic right stroke: protocol for a multicentre double-blind randomised sham-controlled trial

INTRODUCTION

Patients with right stroke lesion have postural and balance disorders, including weight-bearing asymmetry, more pronounced than patients with left stroke lesion. Spatial cognition disorders post-stroke, such as misperceptions of subjective straight-ahead and subjective longitudinal body axis, are suspected to be involved in these postural and balance disorders. Prismatic adaptation has showed beneficial effects to reduce visuomotor disorders but also an expansion of effects on cognitive functions, including spatial cognition. Preliminary studies with a low level of evidence have suggested positive effects of prismatic adaptation on weight-bearing asymmetry and balance after stroke. The objective is to investigate the effects of this intervention on balance but also on postural disorders, subjective straight-ahead, longitudinal body axis and autonomy in patients with chronic right stroke lesion.

METHODS AND ANALYSIS

In this multicentre randomised double-blind sham-controlled trial, we will include 28 patients aged from 18 to 80 years, with a first right supratentorial stroke lesion at chronic stage (≥12 months) and having a bearing ≥60% of body weight on the right lower limb. Participants will be randomly assigned to the experimental group (performing pointing tasks while wearing glasses shifting optical axis of 10 degrees towards the right side) or to the control group (performing the same procedure while wearing neutral glasses without optical deviation). All participants will receive a 20 min daily session for 2 weeks in addition to conventional rehabilitation. The primary outcome will be the balance measured using the Berg Balance Scale. Secondary outcomes will include weight-bearing asymmetry and parameters of body sway during static posturographic assessments, as well as lateropulsion (measured using the Scale for Contraversive Pushing), subjective straight-ahead, longitudinal body axis and autonomy (measured using the Barthel Index).

ETHICS AND DISSEMINATION

The study has been approved by the ethical review board in France. Findings will be submitted to peer-reviewed journals relative to rehabilitation or stroke.

TRIAL REGISTRATION NUMBER

NCT03154138.

Preexisting brain lesions in patients with post stroke pusher behavior and their association with the recovery period: A one year retrospective cohort study in a rehabilitation setting

The presence of preexisting brain lesions due to previous stroke and cerebral small vessel disease has been reported to influence stroke related disability or rehabilitation outcomes. However, there is no data about the impact of such lesions on the recovery period after pusher behavior (PB). This retrospective cohort study aimed to determine the influence of preexisting brain lesions on PB recovery time. Nineteen patients who were suffering from PB were included in the study. The presence of preexisting brain lesions, including previous stroke, silent brain infarcts, microbleed, white matter hyperintensity, and enlarged perivascular spaces were assessed using medical history reports, radiological reports, and magnetic resonance imaging data. The lesion score, ranging from 0 to 6, was calculated based on each preexisting brain lesion. The time to recovery from PB was assessed using the Scale for Contraversive Pushing. Based on the median value of the lesion score, we divided patients into those with a lesion score <2 and those with a lesion score ≥2. A Kaplan Meier survival analysis was performed between these two groups. A multivariable Cox proportional hazards analysis was also performed using the side with hemiparesis and the score of preexisting brain lesions as covariates to determine the hazard ratio. The results showed that the group with a lesion score ≥2 had significantly delayed recovery from PB and the hazard ratio of preexisting brain lesions score was 0.458 (95 % confidence interval: 0.221, 0.949), while the side of hemiparesis was not identified a significant covariate. Our results indicated that patients with PB having higher score of preexisting brain abnormalities might require a longer time to recover, and this might be useful in planning inpatient rehabilitation and treatment goals for patients with PB.

Effects of Cognitive Sensory Motor Training on Lower Extremity Muscle Strength and Balance in Post Stroke Patients: A Randomized Controlled Study

BACKGROUND

Sensory motor impairment, the most common neuromuscular condition in stroke patients, often contributes to muscle weakness and imbalance.

OBJECTIVE

The purpose of this research was to investigate the effects of cognitive sensory-motor training (CSMT) on the muscle strength and balance ability in post-stroke patients.

METHODS

Thirty-five participants after stroke were randomly assigned to the CSMT (n = 17) or control group (n = 18). All participants received 30 min of training each time, five times per week, for six weeks. Lower extremity muscle strength of tibialis anterior (LEMTA) was evaluated using a digital muscular dynamometer. The Medical Research Council (MRC) scale was used to evaluate muscle strengths of the hip joint, knee joint, and ankle joint. For balance ability test, the center of pressure (COP) movement distance and limited of stability (LOS) were measured using BioRescue.

RESULTS

LEMTA, MRC scale, balance ability were significantly more improved in the CSMT group than in the control group (p < 0.05).

CONCLUSIONS

Our findings indicate that CSMT is beneficial and effective for improving muscle strength of the lower extremity and balance ability of post-stroke patients.

Contribution of Basal Ganglia to the Sense of Upright: A Double-Blind Within-Person Randomized Trial of Subthalamic Stimulation in Parkinson's Disease with Pisa Syndrome

BACKGROUND

Verticality perception is frequently altered in Parkinson's disease (PD) with Pisa syndrome (PS). Is it the cause or the consequence of the PS?

OBJECTIVE

We tested the hypothesis that both scenarios coexist.

METHODS

We performed a double-blind within-person randomized trial (NCT02704910) in 18 individuals (median age 63.5 years) with PD evolving for a median of 17.5 years and PS for 2.5 years and treated with bilateral stimulation of the subthalamus nuclei (STN-DBS) for 6.5 years. We analyzed whether head and trunk orientations were congruent with the visual (VV) and postural (PV) vertical, and whether switching on one or both sides of the STN-DBS could modulate trunk orientation via verticality representation.

RESULTS

The tilted verticality perception could explain the PS in 6/18 (33%) patients, overall in three right-handers (17%) who showed net and congruent leftward trunk and PV tilts. Two of the 18 (11%) had an outstanding clinical picture associating leftward: predominant parkinsonian symptoms, whole-body tilt (head -11°, trunk -8°) and transmodal tilt in verticality perception (PV -10°, VV -8.9°). Trunk orientation or VV were not modulated by STN-DBS, whereas PV tilts were attenuated by unilateral or bilateral stimulations if it was applied on the opposite STN.

CONCLUSION

In most cases of PS, verticality perception is altered by the body deformity. In some cases, PS seems secondary to a biased internal model of verticality, and DBS on the side of the most denervated STN attenuated PV tilts with a quasi-immediate effect. This is an interesting track for further clinical studies.

Lateropulsion After Hemispheric Stroke: A Form of Spatial Neglect Involving Graviception

OBJECTIVE

To test the hypothesis that lateropulsion is an entity expressing an impaired body orientation with respect to gravity in relation to a biased graviception and spatial neglect.

METHODS

Data from the DOBRAS cohort (ClinicalTrials.gov: NCT03203109) were collected 30 days after a first hemisphere stroke. Lateral body tilt, pushing, and resistance were assessed with the Scale for Contraversive Pushing.

RESULTS

Among 220 individuals, 72% were upright and 28% showed lateropulsion (tilters [14%] less severe than pushers [14%]). The 3 signs had very high factor loadings (>0.90) on a same dimension, demonstrating that lateropulsion was effectively an entity comprising body tilt (cardinal sign), pushing, and resistance. The factorial analyses also showed that lateropulsion was inseparable from the visual vertical (VV), a criterion referring to vertical orientation (graviception). Contralesional VV biases were frequent (44%), with a magnitude related to lateropulsion severity: upright -0.6° (-2.9; 2.4), tilters -2.9° (-7; 0.8), and pushers -12.3° (-15.4; -8.5). Ipsilesional VV biases were less frequent and milder (p < 0.001). They did not deal with graviception, 84% being found in upright individuals. Multivariate, factorial, contingency, and prediction analyses congruently showed strong similarities between lateropulsion and spatial neglect, the latter encompassing the former.

CONCLUSIONS

Lateropulsion (pusher syndrome) is a trinity constituted by body tilt, pushing, and resistance. It is a way to adjust the body orientation in the roll plane to a wrong reference of verticality. Referring to straight above, lateropulsion might correspond to a form of spatial neglect (referring to straight ahead), which would advocate for 3D maps in the human brain involving the internal model of verticality.

Recovery of balance and gait after stroke is deteriorated by confluent white matter hyperintensities: Cohort study

BACKGROUND

White matter hyperintensities (WMHs) are well known to affect post-stroke disability, mainly by cognitive impairment. Their impact on post-stroke balance and gait disorders is unclear.

OBJECTIVES

We aimed to test the hypothesis that WMHs would independently deteriorate post-stroke balance and gait recovery.

METHODS

This study was performed in 210 individuals of the cohort Determinants of Balance Recovery After Stroke (DOBRAS), consecutively enrolled after a first-ever hemisphere stroke. Clinical data were systematically collected on day 30±3 (D30) post-stroke and at discharge from the rehabilitation ward. WMHs were searched on MRI, graded with the Fazekas scale, and dichotomized as no/mild (absence/sparse) or moderate/severe (confluent). The primary endpoint was the recovery of the single limb stance, assessed with the Postural Assessment Scale for Stroke (PASS). The secondary endpoint was the recovery of independent gait, assessed with the modified Fugl-Meyer Gait Assessment (mFMA). The adjusted hazard ratios (aHRs) of achievements of these endpoints by level of WMHs were estimated by using Cox models, accounting for other relevant clinical and imaging factors.

RESULTS

Individuals with moderate/severe WMHs (n=86, 41%) had greater balance and gait disorders and were more often fallers than others (n=124, 59%). Overall, they had worse and slower recovery of single limb stance and independent gait (p<0.001). Moderate/severe WMHs was the most detrimental factor for recovery of balance (aHR 0.46, 95% confidence interval [CI] 0.32-0.68, p<0.001) and gait (0.51, 0.35-0.74, p<0.001), along with age, stroke severity, lesion volume and disrupted corticospinal tract. With cerebral infarct, endovascular treatments had an independent positive effect, both on the recovery of balance (aHR 1.65, 95% CI 1.13-2.4, p=0.009) and gait (1.78, 1.24-2.55, p=0.002).

CONCLUSIONS

WMHs magnify balance and gait disorders after stroke and worsen their recovery. They should be better accounted for in post-stroke rehabilitation, especially to help establish a prognosis of mobility. ClinicalTrials.gov registration: NCT03203109.