Cardiorespiratory Fitness Benefits of High-Intensity Interval Training After Stroke: A Randomized Controlled Trial.

BACKGROUND: Limited evidence supports the effects of short-interval high-intensity interval training (HIIT) for improving cardiorespiratory fitness (V̇O2peak) after stroke. We aimed to compare the effects of 12 weeks of short-interval HIIT versus moderate-intensity continuous training (MICT) on V̇O2peak, cardiovascular risk factors, and mobility outcomes among individuals ≥6 months poststroke. METHODS: This study was a multi-site, 12-week randomized controlled trial (NCT03614585) with an 8-week follow-up. Participants were randomized into 3 d/wk of HIIT (10×1 minute 80%-100% heart rate reserve interspersed with 1 minute 30% heart rate reserve [19 minutes]) or MICT (20-30 minutes 40%-60% heart rate reserve). Secondary outcomes of the trial, including V̇O2peak, cardiovascular risk factors (carotid-femoral pulse wave velocity, blood pressure, and waist-hip ratio), and mobility (6-minute walk test, 10 m gait speed), were reported. Linear mixed model analyses with a group×study time point interaction evaluated between-group differences. RESULTS: Of the 305 potential participants, 82 consented (mean [SD] age 64.9 [9.3] years, 32 females [39%], 1.8 [1.2] years poststroke) and were randomized to HIIT (n=42, mean [SD] baseline V̇O2peak 17.3 [5.9] mL/kg·min) or MICT (n=40, mean [SD] baseline V̇O2peak 17.2 [6.0] mL/kg·min). Participants attended 82% of visits (n=2417/2952). No adverse events occurred during the study period. A significant group×study time point interaction was found (χ2=8.46; P=0.015) for V̇O2peak at 12 weeks (mean difference, 1.81 [95% CI, 0.58-3.04]; P=0.004) whereby the HIIT group had greater gains in V̇O2peak (∆3.52 mL/kg·min [95% CI, 2.47-4.57]; P<0.001) compared with the MICT group (∆1.71 mL/kg·min [95% CI, 0.55-2.86]; P=0.001). There was no between-group difference in V̇O2peak (mean difference, 1.08 [95% CI, -0.26 to 2.42]; P=0.11) at 8-week follow-up. No group×study time point interactions were found for cardiovascular risk factors or mobility outcomes. CONCLUSIONS: Short-interval HIIT may be an effective alternative to MICT for improving V̇O2peak at 12 weeks postintervention. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT03614585.

Walking with robot-generated haptic forces in a virtual environment: a new approach to analyze lower limb coordination.

BACKGROUND: Walking with a haptic tensile force applied to the hand in a virtual environment (VE) can induce adaptation effects in both chronic stroke and non-stroke individuals. These effects are reflected in spatiotemporal outcomes such as gait speed. However, the concurrent kinematic changes occurring in bilateral lower limb coordination have yet to be explored. METHODS: Chronic stroke participants were stratified based on overground gait speed into lower functioning (LF < 0.8 m/s, N = 7) and higher functioning (HF ≥ 0.8 m/s, N = 7) subgroups. These subgroups and an age-matched control group (N = 14, CG) walked on a self-paced treadmill in a VE with either robot-generated haptic leash forces delivered to the hand and then released or with an instrumented cane. Walking in both leash (10 and 15 N) and cane conditions were compared to pre-force baseline values to evaluate changes in lower limb coordination outcomes. RESULTS: All groups showed some kinematic changes in thigh, leg and foot segments when gait speed increased during force and post-force leash as well as cane walking. These changes were also reflected in intersegmental coordination and 3D phase diagrams, which illustrated increased intersegmental trajectory areas (p < 0.05) and angular velocity. These increases could also be observed when the paretic leg transitions from stance to swing phases while walking with the haptic leash. The Sobolev norm values accounted for both angular position and angular velocity, providing a single value for potentially quantifying bilateral (i.e. non-paretic vs paretic) coordination during walking. These values tended to increase (p < 0.05) proportionally for both limbs during force and post-force epochs as gait speed tended to increase. CONCLUSIONS: Individuals with chronic stroke who increased their gait speed when walking with tensile haptic forces and immediately after force removal, also displayed moderate concurrent changes in lower limb intersegmental coordination patterns in terms of angular displacement and velocity. Similar results were also seen with cane walking. Although symmetry was less affected, these findings appear favourable to the functional recovery of gait. Both the use of 3D phase diagrams and assigning Sobolev norm values are potentially effective for detecting and quantifying these coordination changes.

Slip-Fall Predictors in Community-Dwelling, Ambulatory Stroke Survivors: A Cross-sectional Study.

BACKGROUND AND PURPOSE: Considering the multifactorial nature and the often-grave consequences of falls in people with chronic stroke (PwCS), determining measurements that best predict fall risk is essential for identifying those who are at high risk. We aimed to determine measures from the domains of the International Classification of Functioning, Disability and Health (ICF) that can predict laboratory-induced slip-related fall risk among PwCS. METHODS: Fifty-six PwCS participated in the experiment in which they were subjected to an unannounced slip of the paretic leg while walking on an overground walkway. Prior to the slip, they were given a battery of tests to assess fall risk factors. Balance was assessed using performance-based tests and instrumented measures. Other fall risk factors assessed were severity of sensorimotor impairment, muscle strength, physical activity level, and psychosocial factors. Logistic regression analysis was performed for all variables. The accuracy of each measure was examined based on its sensitivity and specificity for fall risk prediction. RESULTS: Of the 56 participants, 24 (43%) fell upon slipping while 32 (57%) recovered their balance. The multivariate logistic regression analysis model identified dynamic gait stability, hip extensor strength, and the Timed Up and Go (TUG) score as significant laboratory-induced slip-fall predictors with a combined sensitivity of 75%, a specificity of 79.2%, and an overall accuracy of 77.3%. DISCUSSION AND CONCLUSIONS: The results indicate that fall risk measures within the ICF domains-body, structure, and function (dynamic gait stability and hip extensor strength) and activity limitation (TUG)-could provide a sensitive laboratory-induced slip-fall prediction model in PwCS.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A323).

Adding Light Touch While Walking in Older Adults: Biomechanical and Neuromotor Effects.

Adding haptic input may improve balance control and help prevent falls in older adults. This study examined the effects of added haptic input via light touch on a railing while walking. Participants (N = 53, 75.9 ± 7.9 years) walked normally or in tandem (heel to toe) with and without haptic input. During normal walking, adding haptic input resulted in a more cautious and variable gait pattern, reduced variability of center of mass acceleration and margin of stability, and increased muscle activity. During tandem walking, haptic input had minimal effect on step parameters, decreased lower limb muscle activity, and increased cocontraction at the ankle closest to the railing. Age was correlated with step width variability, stride length variability, stride velocity, variability of medial-lateral center of mass acceleration, and margin of stability for tandem walking. This complex picture of sensorimotor integration in older adults warrants further exploration into added haptic input during walking.

Drosophila Exo70 Is Essential for Neurite Extension and Survival under Thermal Stress.

The octomeric exocyst complex governs the final step of exocytosis in both plants and animals. Its roles, however, extend beyond exocytosis and include organelle biogenesis, ciliogenesis, cell migration, and cell growth. Exo70 is a conserved component of the exocyst whose function in Drosophila is unclear. In this study, we characterized two mutant alleles of Drosophila exo70. exo70 mutants exhibit reduced synaptic growth, locomotor activity, glutamate receptor density, and mEPSP amplitude. We found that presynaptic Exo70 is necessary for normal synaptic growth at the neuromuscular junction (NMJ). At the neuromuscular junction, exo70 genetically interacts with the small GTPase ralA to regulate synaptic growth. Loss of Exo70 leads to the blockage of JNK signaling-, activity-, and temperature-induced synaptic outgrowths. We showed that this phenotype is associated with an impairment of integral membrane protein transport to the cell surface at synaptic terminals. In octopaminergic motor neurons, Exo70 is detected in synaptic varicosities, as well as the regions of membrane extensions in response to activity stimulation. Strikingly, mild thermal stress causes severe neurite outgrowth defects and pharate adult lethality in exo70 mutants. exo70 mutants also display defective locomotor activity in response to starvation stress. These results demonstrated that Exo70 is an important regulator of induced synaptic growth and is crucial for an organism's adaptation to environmental changes.SIGNIFICANCE STATEMENT The exocyst complex is a conserved protein complex directing secretory vesicles to the site of membrane fusion during exocytosis, which is essential for transporting proteins and membranes to the cell surface. Exo70 is a subunit of the exocyst complex whose roles in neurons remain elusive, and its function in Drosophila is unclear. In Drosophila, Exo70 is expressed in both glutamatergic and octopaminergic neurons, and presynaptic Exo70 regulates synaptic outgrowth. Moreover, exo70 mutants have impaired integral membrane transport to the cell surface at synaptic terminals and block several kinds of induced synaptic growth. Remarkably, elevated temperature causes severe arborization defects and lethality in exo70 mutants, thus underpinning the importance of Exo70 functions in development and adaptation to the environment.

Validity and Responsiveness of the Visual Vertigo Analogue Scale.

BACKGROUND AND PURPOSE: People with visual vertigo have dizziness provoked by visual stimulation. We have developed a Visual Vertigo Analogue Scale (VVAS) to evaluate their symptoms and response to rehabilitation. Our goal was to validate the VVAS against the Situation Characteristics Questionnaire (SITQ) score and determine its responsiveness to treatment. METHODS: Participants (n = 115) completed 3 questionnaires: Dizziness Handicap Inventory (DHI), VVAS, and the SITQ at their initial and final sessions of vestibular rehabilitation. The SITQ was analyzed using the Space Motion Discomfort (SMD1) outcome measure and by calculating the average score of all the items (SMDavg). The results were stratified into those who had a significant clinical change in their DHI score posttreatment and those who did not. Associations of the VVAS with SMD scores and change scores were determined by Pearson and Spearman correlations. Nonparametric t tests were used to compare the 2 DHI groups on the clinical outcomes. RESULTS: There were significant associations between VVAS scores (P < 0.0001) and both SMD1 (ßVVAS = 0.02) and SMDavg scores (ßVVAS = 0.03). Significant differences existed between the 2 DHI groups for all scores: VVAS (P = 0.0002), SMD1 (P = 0.02), and SMDavg (P = 0.0001). DISCUSSION AND CONCLUSIONS: VVAS scores correlated well with SMD1 and SMDavg scores. Changes in VVAS pre- and posttreatment scores corresponded to the changes seen in SMD1 and SMDavg scores. The VVAS shows validity and responsiveness to change. The VVAS can be used to detect clients with visual vertigo and to verify the progression of the client's symptoms.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A258).

Effects of Age on Obstacle Avoidance while Walking and Deciphering Text versus Audio Phone Messages.

BACKGROUND: Widely popular among young, and more recently older adults, mobile phones are increasingly used while walking. Knowledge of the impact of phone message modality (e.g., text vs. audio) on the ability to avoid collisions with other pedestrians, however, remains limited. OBJECTIVES: This study aimed to investigate the extent to which the circumvention of an approaching pedestrian is affected by text versus audio phone messages in healthy young and older adults. METHOD: Sixteen young (aged 24 ± 3 years) and 14 older adults (aged 68 ± 4.5 years) were tested while walking and viewing a virtual environment depicted as a subway station in a helmet-mounted display. As they walked, one of three virtual humans randomly approached from the center (0°), right (+40°), or left (+40°). Phone messages, when present, were delivered at obstacle displacement onset and presented either as text messages on a virtual phone or as audio messages delivered through earphones. Participants were instructed to avoid collisions with pedestrians and to fully report the message content at the end of trials. RESULTS: Both groups showed decreased accuracy of message report (AMR), slower walking speed, and more collisions in response to text versus audio messages. Compared to young adults, older adults showed greater reduction in AMR, more collisions, and similar speed adaptation in the presence of text messages. In both age groups, no significant differences in walking speed emerged between the audio message and the no-message condition, but only older adults experienced collisions and reduced AMR with the audio messages. Obstacle clearance and the onset time of avoidance strategy were not affected by message condition. CONCLUSIONS: Results suggest that coping with text messages while walking leads to greater risk of collision and alters message deciphering accuracy, while audio messages stand out as a safer and more efficient alternative for on-the-go communication. In general, older adults experienced larger motor-cognitive interference than younger adults, resulting in reduced AMR and more collisions without further changes in gait adaptation. Consequently, older adults failed to prioritize their safety when attending to phone messages while walking.

Modeling spatial navigation in the presence of dynamic obstacles: a differential games approach.

Obstacle circumvention strategies can be shaped by the dynamic interaction of an individual (evader) and an obstacle (pursuer). We have developed a mathematical model with predictive and emergent components, using experimental data from seven healthy young adults walking toward a target while avoiding collision with a stationary or moving obstacle (approaching head-on, or diagonally 30° left or right) in a virtual environment. Two linear properties from the predictive component enable the evader to predict the minimum distance between itself and the obstacle at all times, including the future intersection of trajectories. The emergent component uses the classical differential games model to solve for an optimal circumvention while reaching the target, wherein the locomotor strategy is influenced by the obstacle, target, and the evader velocity. Both model components were fitted to a different set of experimental data obtained from five poststroke and healthy participants to derive the minimum predicted distance (predictive component) and obstacle influence dimensions (emergent component) during circumvention. Minimum predicted distance between evader and pursuer was kept constant when the evader was closest to the obstacle in all participants. Obstacle influence dimensions varied depending on obstacle approach condition and preferred side of circumvention, reflecting differences in locomotor strategies between poststroke and healthy individuals. Additionally, important associations between model outputs and observed experimental outcomes were found. The model, supported by experimental data, suggests that both predictive and emergent processes can shape obstacle circumvention strategies in healthy and poststroke individuals. NEW & NOTEWORTHY Obstacle circumvention during goal-directed locomotion is modeled with a new mathematical approach comprising both predictive and emergent elements. The major novelty is using differential games solutions to illustrate the dynamic interactions between the individual as an evader and the approaching obstacle as a pursuer. The model is supported by experimental evidence that explains the behavior along the continuum of locomotor adaptation displayed by healthy subjects and individuals with stroke.

Adaptation and post-adaptation effects of haptic forces on locomotion in healthy young adults.

BACKGROUND: Developing rehabilitation strategies to improve functional walking and postural control in patients is a priority for rehabilitation clinicians and researchers alike. One possible strategy is the use of sensory modalities to elicit adaptive locomotor gait patterns. This study aimed to explore to what extent haptic inputs, in the form of forward-leading tensile forces delivered to the hand, compared to no force, may lead to adaptation and post-adaptation effects on gait parameters, during and after the haptic exposure, respectively. METHODS: Thirteen healthy young individuals were recruited for this study. We developed an innovative system combining virtual reality and haptic tensile forces in the direction of locomotion to simulate walking with a dog. A robotic arm generated forces via an adapted leash to the participant's hand while they walked on a self-paced treadmill immersed in a virtual environment with scene progression synchronized to the treadmill. RESULTS: All participants showed significant increases in instantaneous gait velocity and stride length, with accompanying decreases in double-limb support time (p < 0.05) when walking with a haptic tensile force of either 10 or 20 N, relative to pre-force epoch levels, indicating an adaptation effect. When the 10 or 20 N force was removed, gait measures generally remained changed relative to baseline pre-force levels (p < 0.05), providing evidence of a post-adaptation effect. CONCLUSIONS: Changes in spatiotemporal outcomes provide evidence that both adaptation and post-adaptation effects were present in response to the application and removal of a haptic force. Future studies will investigate whether similar changes in elderly and post-stroke populations can be actualized during steady-state walking.

Locomotor circumvention strategies are altered by stroke: I. Obstacle clearance.

BACKGROUND: Functional locomotion requires the ability to adapt to environmental challenges such as the presence of stationary or moving obstacles. Difficulties in obstacle circumvention often lead to restricted community ambulation in individuals with stroke. The objective of this study was to contrast obstacle circumvention strategies between post-stroke (n = 12) and healthy individuals (n = 12) performing locomotor and perceptuomotor (joystick navigation) tasks with different obstacle approaches. METHODS: Participants walked and navigated with a joystick towards a central target, in a virtual environment simulating a large room, while avoiding an obstacle that either remained stationary at the pre-determined point of intersection or moved from head-on or diagonally 30° left/right. The outcome measures included dynamic clearance (DC), instantaneous distance from obstacle at crossing (IDC), number of collisions and preferred side of circumvention. These measures were compared between groups (stroke vs. healthy), obstacle parameter (stationary vs. moving head-on) and direction of approach (left/paretic vs. right/non-paretic). RESULTS: DC was significantly larger when circumventing a moving obstacle that approached head-on as compared to a stationary obstacle for both groups during both tasks, while not significantly different in either diagonal approach in either group. IDC was smaller in the stroke group while walking and larger in both groups during joystick navigation when avoiding moving as compared to stationary obstacle. IDC was significantly larger in the stroke group compared to controls for diagonal approaches during walking, wherein two different strategies emerged amongst individuals with stroke: circumventing to the same (Vsame n = 6) or opposite (Vopp n = 4) side of obstacle approach. This behavior was not seen in the perceptuomotor task, wherein post-stroke participants circumvented to opposite side of the obstacle approach as seen in healthy participants. In the locomotor task, the Vsame subgroup that had greater functional limitations used larger DC as compared to the Vopp subgroup and healthy individuals. The remaining two individuals with stroke collided with obstacles in >50% trials of either obstacle approach. The underlying mechanisms for collision were however different for both individuals. CONCLUSION: Avoidance strategies in individuals with stroke can vary depending on the individual locomotor capabilities and obstacle characteristics.

Locomotor circumvention strategies are altered by stroke: II. Postural Coordination.

BACKGROUND: Locomotor strategies for obstacle circumvention require appropriate postural coordination that depends on sensorimotor integration within the central nervous system. It is not known how these strategies are affected by a stroke. The objective of this study was to contrast postural coordination strategies used for obstacle circumvention between post-stroke participants (n = 12) and healthy controls (n = 12). METHODS: Participants walked towards a target in a virtual environment (11 × 8 m room) with cylindrical obstacles that were stationary or approaching from head-on, or diagonally 30° left/right. RESULTS: Two stepping strategies for obstacle circumvention were identified: 1) side step: increase in step width by the foot ipsilateral to the side of circumvention; 2) cross step: decrease in step width by the foot contralateral to the side of circumvention. The side step strategy was favoured by post-stroke individuals in circumventing stationary and head-on approaching obstacles. In circumventing diagonally approaching obstacles, healthy controls generally veered opposite to obstacle approach (>60% trials), whereas the majority of post-stroke participants (7/12) veered to the same side of obstacle approach (Vsame). Post-stroke participants who veered to the opposite side (Vopp, 5/12) were more independent and faster ambulators who favoured the side step strategy in circumventing obstacles approaching from the paretic side and cross step strategy for obstacles approaching from the non-paretic side. Vsame participants generally favoured the side step strategy for both diagonal approaches. Segmental rotation amplitudes and latencies were largest in the Vsame group, and significantly greater in post-stroke participants than controls for all obstacle conditions. All participants initiated circumvention with the feet followed by the pelvis and thorax, demonstrating a caudal-rostral sequence of reorientation. CONCLUSION: Postural coordination strategies for obstacle circumvention were altered post stroke, depending on the residual or restored functional abilities. Segmental re-orientations are also affected by the motion and direction of obstacle.

Efficacy of virtual reality-based intervention on balance and mobility disorders post-stroke: a scoping review.

Rehabilitation interventions involving virtual reality (VR) technology have been developed for the promotion of functional independence post stroke. A scoping review was performed to examine the efficacy of VR-based interventions on balance and mobility disorders post stroke. Twenty-four articles in the English language examining VR game-based interventions and outcomes directed at balance and mobility disorders were included. Various VR systems (customized and commercially available) were used as rehabilitation tools. Outcome measures included laboratory and clinical measures of balance and gait. Outcome measures of dynamic balance showed significant improvements following VR-based interventions as compared to other interventions. Further, it was observed that VR-based intervention may have favorable effects in improving walking speed and the ability to deal with environmental challenges, which may also facilitate independent community ambulation. VR-based therapy thus has the potential to be a useful tool for balance and gait training for stroke rehabilitation. Utilization of motor learning principles related to task-related training may have been an important factor leading to positive results. Other principles such as repetition, feedback etc. were used in studies but were not explored explicitly and may need to be investigated to further improve the strength of results. Lastly, robust study designs with appropriate attention towards the intensity and dose-response aspects of VR training, clear study objectives and suitable outcomes would further aid in determining evidence-based efficacy for VR game-based interventions in the future.

Application of an Auditory-Based Feedback Distortion to Modify Gait Symmetry in Healthy Individuals.

BACKGROUND: Augmenting auditory feedback through an error-augmentation paradigm could facilitate the perception and correction of gait asymmetry in stroke survivors, but how such a paradigm should be tailored to individual asymmetry profiles remains unclear. Before implementing the paradigm in rehabilitation, we need to investigate the instantaneous effects of distorted footstep sound feedback on gait symmetry in healthy young adults. METHODS: Participants (n = 12) walked on a self-paced treadmill while listening to their footstep sounds, which were distorted unilaterally according to five conditions presented randomly: small delay; small advance; large delay; large advance; or unmodified (control). The primary outcomes were swing time ratio (SWR) and step length ratio (SLR). Secondary outcomes included walking speed, bilateral swing time, step length, and maximum toe height, as well as hip, knee, and ankle angle excursions. RESULTS: SWR (p < 0.001) but not SLR (p ≥ 0.05) was increased in all distorted feedback conditions compared to the control condition. Increased swing time on the perturbed side ipsilateral to feedback distortion was observed in the advanced conditions (p < 0.001), while swing time increased bilaterally in the delayed conditions (p < 0.001) but to a larger extent on the unperturbed side contralateral to feedback distortion. Increases in swing time were accompanied by larger maximum toe height as well as larger hip and knee joint excursions (p < 0.05 to p < 0.001). No differences in any outcomes were observed between small and large feedback distortion magnitudes. CONCLUSIONS: Distorted footstep sound feedback successfully elicits adaptation in temporal gait symmetry (SWR), with distinct modulation patterns for advanced vs. delayed footstep sounds. Spatial symmetry (SLR) remains unaltered, likely because auditory feedback primarily conveys temporal information. This research lays the groundwork to implement personalized augmented auditory feedback in neurorehabilitation.

Rehabilitation Oculomotor Screening Evaluation (ROSE)-A Proof-of-Principle Study for Acquired Brain Injuries.

Background/Objectives: Acquired brain injury (ABI) is a major cause of global disability. Many ABI patients exhibit oculomotor dysfunctions that impact their daily life and rehabilitation outcomes. Current clinical tools for oculomotor function (OMF) assessment are limited in their usability. In this proof-of-principle study, we aimed to develop an efficient tool for OMF screening and to assess the feasibility, acceptability, and relevance in a small sample of ABI and control participants. Methods: We created the Rehabilitation Oculomotor Screening Evaluation (ROSE) by reviewing existing OMF assessments. ROSE was pilot-tested on ABI patients (n = 10) and age-matched controls (n = 10). Data regarding the characteristics of the assessment, such as the duration, level of participant comprehension, and participant experience were also collected. Results: ROSE takes <20 min (x¯ = 12.5), is easy to complete (agreement x¯ = 4.6/5), and is well-accepted (x¯ = 4.8/5). Patients scored higher in all subtests and total score (x¯ = 34.8 for ABI vs. 8.9 for controls). Most subtests did not provoke any symptoms, especially for controls. There were no significant between-group differences in symptom provocation. This proof-of-principle study shows that ROSE is feasible, acceptable, and relevant for adult ABI patients. Conclusions: ROSE needs further evaluation for reliability testing and validation in larger samples and diverse neurological conditions. Establishing norms for various ages, sexes, and populations should be considered for the deployment of ROSE as an OMF clinical tool.

Measuring Neuroplasticity in Response to Cardiovascular Exercise in People With Stroke: A Critical Perspective.

BACKGROUND: Rehabilitative treatments that promote neuroplasticity are believed to improve recovery after stroke. Animal studies have shown that cardiovascular exercise (CE) promotes neuroplasticity but the effects of this intervention on the human brain and its implications for the functional recovery of patients remain unclear. The use of biomarkers has enabled the assessment of cellular and molecular events that occur in the central nervous system after brain injury. Some of these biomarkers have proven to be particularly valuable for the diagnosis of severity, prognosis of recovery, as well as for measuring the neuroplastic response to different treatments after stroke. OBJECTIVES: To provide a critical analysis on the current evidence supporting the use of neurophysiological, neuroimaging, and blood biomarkers to assess the neuroplastic response to CE in individuals poststroke. RESULTS: Most biomarkers used are responsive to the effects of acute and chronic CE interventions, but the response appears to be variable and is not consistently associated with functional improvements. Small sample sizes, methodological variability, incomplete information regarding patient's characteristics, inadequate standardization of training parameters, and lack of reporting of associations with functional outcomes preclude the quantification of the neuroplastic effects of CE poststroke using biomarkers. CONCLUSION: Consensus on the optimal biomarkers to monitor the neuroplastic response to CE is currently lacking. By addressing critical methodological issues, future studies could advance our understanding of the use of biomarkers to measure the impact of CE on neuroplasticity and functional recovery in patients with stroke.

A Pilot Study to Assess Visual Vertigo in People with Persistent Postural-Perceptual Dizziness with a New Computer-Based Tool.

BACKGROUND: Visual vertigo (VV) is a common symptom in people with persistent postural-perceptual dizziness (PPPD). Few subjective scales are validated for assessing the intensity of VV, yet these scales are limited by recall bias, as they require individuals to rate their symptoms from memory. The computer-Visual Vertigo Analogue Scale (c-VVAS) was developed by adapting five scenarios from the original paper-VVAS (p-VVAS) into 30 s video clips. The aim of this pilot study was to develop and test a computerized video-based tool for the assessment of visual vertigo in people with PPPD. METHODS: PPPD participants (n = 8) and age- and sex-matched controls (n = 8) completed the traditional p-VVAS and the c-VVAS. A questionnaire about their experiences using the c-VVAS was completed by all participants. RESULTS: There was a significant difference between the c-VVAS scores from the PPPD and the control group (Mann-Whitney, p < 0.05). The correlation between the total c-VVAS scores and the total c-VVAS scores was not significant (r = 0.668, p = 0.07). The study showed a high acceptance rate of the c-VVAS by participants (mean = 91.74%). CONCLUSION: This pilot study found that the c-VVAS can distinguish PPPD subjects from healthy controls and that it was well-received by all participants.

Development of a virtual reality-based intervention for community walking post stroke: an integrated knowledge translation approach.

PURPOSE: To develop a virtual reality (VR) based intervention targeting community walking requirements. METHODS: Two focus groups each involving 7 clinicians allowed exploring optimal features, needed support and perceived favorable/unfavorable factors associated with the use of the VR-based intervention from the clinicians' perspective. Three stroke survivors and 2 clinicians further interacted with the intervention and filled questionnaires related to acceptability and favorable/unfavorable perceptions on the VR intervention. Stroke participants additionally rated their perceived effort (NASA Tax Load Index), presence (Slater-Usoh-Steed) and cybersickness (Simulator Sickness Questionnaire). RESULTS: Results identified optimal features (patient eligibility criteria, task complexity), needed support (training, human assistance), as well as favorable (cognitive stimulation, engagement, representativeness of therapeutic goals) and unfavorable factors (misalignment with a natural walking pattern, client suitability, generalization to real-life) associated with the intervention. Acceptability scores following the interaction with the tool were 28 and 42 (max 56) for clinicians and ranged from 43 to 52 for stroke participants. Stroke participants reported moderate perceptions of effort (range:20-33/max:60), high levels of presence (29-42/42) and minimal cybersickness (0-3/64). CONCLUSION: Findings collected in the early development phase of the VR intervention will allow addressing favorable/unfavorable factors and incorporating desired optimal features, prior to conducting effectiveness and implementation studies.

This study presents the development process of a new virtual reality (VR) intervention for community walking and participation in stroke survivors.Results from the focus group and hands-on pilot trial suggest that the VR intervention is feasible and accepted by clinicians and stroke survivors.Addressing favorable/unfavorable factors and incorporating features desired by clinicians in the development of the VR tool should promote its eventual implementation in clinical setting.

Instantaneous effect of real-time avatar visual feedback on interlimb coordination during walking post-stroke.

BACKGROUND: Gait asymmetry, which is common after stroke, is typically characterized using spatiotemporal parameters of gait that do not consider the aspect of movement coordination. In this manuscript, we examined whether an avatar-based feedback provided as a single-session intervention to improve gait symmetry also improved inter-limb coordination among people with stroke and we examined the relationship between changes in coordination and step length symmetry. METHODS: Twelve stroke participants walked on a self-paced treadmill with and without a self-avatar that replicated their locomotor movements in real time. Continuous relative phase and angular coefficient of correspondence calculated using bilateral sagittal hip movements were used to quantify temporal and spatial interlimb coordination, respectively. Spatial gait symmetry, previously shown to improve with the avatar feedback, was quantified using step length ratio between both limbs, with the largest value as numerator. FINDINGS: Participants who improved their spatial symmetry during avatar exposure also improved their temporal coordination, while spatial coordination remained unchanged. Overall, improvements in spatial symmetry correlated positively with improvements in temporal coordination. The non-paretic hip and paretic ankle angle excursion in the sagittal plane also significantly increased during avatar exposure. INTERPRETATION: Improvements in gait symmetry may be explained by changes in interlimb coordination. Current data and existing literature further suggest that such improvements are largely driven by adaptations in non-paretic leg movements, notably at the hip. By providing real-time information on walking movements not affordable in other ways, avatar-based feedback shows great potential to improve gait symmetry and interlimb coordination post-stroke.

Biomedical Research and Informatics Living Laboratory for Innovative Advances of New Technologies in Community Mobility Rehabilitation: Protocol for Evaluation and Rehabilitation of Mobility Across Continuums of Care.

BACKGROUND: Rapid advances in technologies over the past 10 years have enabled large-scale biomedical and psychosocial rehabilitation research to improve the function and social integration of persons with physical impairments across the lifespan. The Biomedical Research and Informatics Living Laboratory for Innovative Advances of New Technologies (BRILLIANT) in community mobility rehabilitation aims to generate evidence-based research to improve rehabilitation for individuals with acquired brain injury (ABI). OBJECTIVE: This study aims to (1) identify the factors limiting or enhancing mobility in real-world community environments (public spaces, including the mall, home, and outdoors) and understand their complex interplay in individuals of all ages with ABI and (2) customize community environment mobility training by identifying, on a continuous basis, the specific rehabilitation strategies and interventions that patient subgroups benefit from most. Here, we present the research and technology plan for the BRILLIANT initiative. METHODS: A cohort of individuals, adults and children, with ABI (N=1500) will be recruited. Patients will be recruited from the acute care and rehabilitation partner centers within 4 health regions (living labs) and followed throughout the continuum of rehabilitation. Participants will also be recruited from the community. Biomedical, clinician-reported, patient-reported, and brain imaging data will be collected. Theme 1 will implement and evaluate the feasibility of collecting data across BRILLIANT living labs and conduct predictive analyses and artificial intelligence (AI) to identify mobility subgroups. Theme 2 will implement, evaluate, and identify community mobility interventions that optimize outcomes for mobility subgroups of patients with ABI. RESULTS: The biomedical infrastructure and equipment have been established across the living labs, and development of the clinician- and patient-reported outcome digital solutions is underway. Recruitment is expected to begin in May 2022. CONCLUSIONS: The program will develop and deploy a comprehensive clinical and community-based mobility-monitoring system to evaluate the factors that result in poor mobility, and develop personalized mobility interventions that are optimized for specific patient subgroups. Technology solutions will be designed to support clinicians and patients to deliver cost-effective care and the right intervention to the right person at the right time to optimize long-term functional potential and meaningful participation in the community. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/12506.

Canadian Stroke Best Practice Recommendations: Virtual Stroke Rehabilitation Interim Consensus Statement 2022.

ABSTRACT: The seventh edition of the Canadian Stroke Best Practice Recommendations for Rehabilitation and Recovery following Stroke includes a new section devoted to the provision of virtual stroke rehabilitation. This consensus statement uses Grading of Recommendations, Assessment, Development and Evaluations methodology and Appraisal of Guidelines for Research & Evaluation II principles. A literature search was conducted using PubMed, Embase, and Cochrane databases. An expert writing group reviewed all evidence and developed recommendations, as well as consensus-based clinical considerations where evidence was insufficient for a recommendation. All recommendations underwent internal and external review. These recommendations apply to hospital, ambulatory care, and community-based settings where virtual stroke rehabilitation is provided. This guidance is relevant to health professionals, people living with stroke, healthcare administrators, and funders. Recommendations address issues of access, eligibility, consent and privacy, technology and planning, training and competency (for healthcare providers, patients and their families), assessment, service delivery, and evaluation. Virtual stroke rehabilitation has been shown to safely and effectively increase access to rehabilitation therapies and care providers, and uptake of these recommendations should be a priority in rehabilitation settings. They are key drivers of access to high-quality evidence-based stroke care regardless of geographical location and personal circumstances in Canada.