Lateropulsion in Right-Sided Stroke: Brain Anatomical Correlates of Severity and Duration.

BACKGROUND AND PURPOSE: Lateropulsion (LP) is a profound disorder of postural control that has a significant impact on neurorehabilitation. Knowledge of relevant brain areas could guide decisions on appropriate intervention methods. Although LP severity and duration are highly variable in individuals with LP, imaging studies on LP have not sufficiently considered these aspects. The aim of this study was to investigate the lesion location in individuals after stroke and the correlation with LP duration and severity. METHODS: A retrospective case-control study using voxel lesion symptom mapping (VLSM) in 74 individuals with right-sided brain lesion (49 with and 25 without LP) was performed to analyze the correlation between lesion location and LP severity. Duration was investigated in a subsample of 22 individuals with LP. LP was diagnosed by means of the Scale for Contraversive Pushing. RESULTS: Individuals with LP showed significantly larger lesion sizes compared with the individuals with no LP. VLSM analysis of LP severity did not reveal statistically significant results. VLSM analysis showed a statistically significant association with longer LP duration for the inferior frontal gyrus, the hippocampus, the inferior parietal gyrus, the supramarginal gyrus, the angular gyrus, the temporal cortex, the sagittal stratum, and the superior longitudinal fasciculus. DISCUSSION AND CONCLUSION: LP-relevant areas are located in the multisensory network. Areas of the frontoparietal network, which are related to spatial cognition, memory, and attention, were found to be relevant for duration and severity. The findings, especially those regarding duration involving the middle temporal cortex, could explain the better intervention outcomes for methods based more on implicit than on explicit knowledge of verticality.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1 available at: http://links.lww.com/JNPT/A433 ).

Sensory Stimulation and Robot-Assisted Arm Training after Stroke: A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Functional recovery after stroke is often limited, despite various treatment methods such as robot-assisted therapy. Repetitive sensory stimulation (RSS) might be a promising add-on therapy that is thought to directly drive plasticity processes. First positive effects on sensorimotor function have been shown. However, clinical studies are scarce, and the effect of RSS combined with robot-assisted training has not been evaluated yet. Therefore, our objective was to investigate the feasibility and sensorimotor effects of RSS (compared to a control group receiving sham stimulation) followed by robot-assisted arm therapy. METHODS: Forty participants in the subacute phase (4.4-23.9 weeks) after stroke with a moderate to severe arm paresis were randomized to RSS or control group. Participants received 12 sessions of (sham-) stimulation within 3 weeks. Stimulation of the fingertips and the robot-assisted therapy were each applied in 45-min sessions. Motor and sensory outcome assessments (e.g. Fugl-Meyer-Assessment, grip strength) were measured at baseline, post intervention and at a 3-week follow-up. RESULTS: Participants in both groups improved their sensorimotor function from baseline to post and follow-up measurements, as illustrated by most motor and sensory outcome assessments. However, no significant group effects were found for any measures at any time (P > 0.058). Stimulations were well accepted, no safety issues arose. DISCUSSION AND CONCLUSIONS: Feasibility of robot-assisted therapy with preceding RSS in persons with moderate to severe paresis was demonstrated. However, RSS preceding robot-assisted training failed to show a preliminary effect compared to the control intervention. Participants might have been too severely affected to identify changes driven by the RSS, or these might have been diluted or more difficult to identify because of the additional robotic training and neurorehabilitation. VIDEO ABSTRACT AVAILABLE: for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A478).

The efficacy of hybrid neuroprostheses in the rehabilitation of upper limb impairment after stroke, a narrative and systematic review with a meta-analysis.

BACKGROUND: Paresis of the upper limb (UL) is the most frequent impairment after a stroke. Hybrid neuroprostheses, i.e., the combination of robots and electrical stimulation, have emerged as an option to treat these impairments. METHODS: To give an overview of existing devices, their features, and how they are linked to clinical metrics, four different databases were systematically searched for studies on hybrid neuroprostheses for UL rehabilitation after stroke. The evidence on the efficacy of hybrid therapies was synthesized. RESULTS: Seventy-three studies were identified, introducing 32 hybrid systems. Among the most recent devices (n = 20), most actively reinforce movement (3 passively) and are typical exoskeletons (3 end-effectors). If classified according to the International Classification of Functioning, Disability and Health, systems for proximal support are expected to affect body structures and functions, while the activity and participation level are targeted when applying Functional Electrical Stimulation distally plus the robotic component proximally. The meta-analysis reveals a significant positive effect on UL functions (p < 0.001), evident in a 7.8-point Mdiff between groups in the Fugl-Meyer assessment. This positive effect remains at the 3-month follow-up (Mdiff = 8.4, p < 0.001). CONCLUSIONS: Hybrid neuroprostheses have a positive effect on UL recovery after stroke, with effects persisting at least three months after the intervention. Non-significant studies were those with the shortest intervention periods and the oldest patients. Improvements in UL functions are not only present in the subacute phase after stroke but also in long-term chronic stages. In addition to further technical development, more RCTs are needed to make assumptions about the determinants of successful therapy.

Sham-controlled randomized multicentre trial of transcranial direct current stimulation for prolonged disorders of consciousness.

BACKGROUND AND PURPOSE: Transcranial direct current stimulation (tDCS) has been shown to improve signs of consciousness in a subset of patients with disorders of consciousness (DoC). However, no multicentre study confirmed its efficacy when applied during rehabilitation. In this randomized controlled double-blind study, the effects of tDCS whilst patients were in rehabilitation were tested at the group level and according to their diagnosis and aetiology to better target DoC patients who might repond to tDCS. METHODS: Patients received 2 mA tDCS or sham applied over the left prefrontal cortex for 4 weeks. Behavioural assessments were performed weekly and up to 3 months' follow-up. Analyses were conducted at the group and subgroup levels based on the diagnosis (minimally conscious state [MCS] and unresponsive wakefulness syndrome) and the aetiology (traumatic or non-traumatic). Interim analyses were planned to continue or stop the trial. RESULTS: The trial was stopped for futility when 62 patients from 10 centres were enrolled (44 ± 14 years, 37 ± 24.5 weeks post-injury, 18 women, 32 MCS, 39 non-traumatic). Whilst, at the group level, no treatment effect was found, the subgroup analyses at 3 months' follow-up revealed a significant improvement for patients in MCS and with traumatic aetiology. CONCLUSIONS: Transcranial direct current stimulation during rehabilitation does not seem to enhance patients' recovery. However, diagnosis and aetiology appear to be important factors leading to a response to the treatment. These findings bring novel insights into possible cortical plasticity changes in DoC patients given these differential results according to the subgroups of patients.

The impact of visuospatial perception on distance judgment and depth perception in an Augmented Reality environment in patients after stroke: an exploratory study.

BACKGROUND: Augmented Reality (AR)-based interventions are applied in neurorehabilitation with increasing frequency. Depth perception is required for the intended interaction within AR environments. Until now, however, it is unclear whether patients after stroke with impaired visuospatial perception (VSP) are able to perceive depth in the AR environment. METHODS: Different aspects of VSP (stereovision and spatial localization/visuoconstruction) were assessed in 20 patients after stroke (mean age: 64 ± 14 years) and 20 healthy subjects (HS, mean age: 28 ± 8 years) using clinical tests. The group of HS was recruited to assess the validity of the developed AR tasks in testing stereovision. To measure perception of holographic objects, three distance judgment tasks and one three-dimensionality task were designed. The effect of impaired stereovision on performance in each AR task was analyzed. AR task performance was modeled by aspects of VSP using separate regression analyses for HS and for patients. RESULTS: In HS, stereovision had a significant effect on the performance in all AR distance judgment tasks (p = 0.021, p = 0.002, p = 0.046) and in the three-dimensionality task (p = 0.003). Individual quality of stereovision significantly predicted the accuracy in each distance judgment task and was highly related to the ability to perceive holograms as three-dimensional (p = 0.001). In stroke-survivors, impaired stereovision had a specific deterioration effect on only one distance judgment task (p = 0.042), whereas the three-dimensionality task was unaffected (p = 0.317). Regression analyses confirmed a lacking impact of patients' quality of stereovision on AR task performance, while spatial localization/visuoconstruction significantly prognosticated the accuracy in distance estimation of geometric objects in two AR tasks. CONCLUSION: Impairments in VSP reduce the ability to estimate distance and to perceive three-dimensionality in an AR environment. While stereovision is key for task performance in HS, spatial localization/visuoconstruction is predominant in patients. Since impairments in VSP are present after stroke, these findings might be crucial when AR is applied for neurorehabilitative treatment. In order to maximize the therapy outcome, the design of AR games should be adapted to patients' impaired VSP.  Trial registration: The trial was not registered, as it was an observational study.

The Subjective Postural Vertical Determined in Patients with Pusher Behavior During Standing.

BACKGROUND: The subjective postural vertical (SPV), i.e., the perceived upright orientation of the body in relation to gravity, is disturbed in patients with pusher behavior. So far, the SPV has been measured only when these patients were sitting, and the results were contradictory as regards the side of the SPV deviation. OBJECTIVE: The objective was to investigate the SPV in patients with different degrees of severity of pusher behavior while standing. METHODS: Eight stroke patients with pusher behavior, ten age-matched stroke patients without pusher behavior, and ten age-matched healthy control subjects were included. The SPV (SPV error, SPV range) was assessed in the pitch and the roll planes. Pusher behavior was classified with the Burke Lateropulsion Scale (BLS). RESULTS: In the pitch plane, the SPV range was significantly larger in pusher patients than in patients without pusher behavior or healthy controls. The SPV error was similar for groups. In the roll plane, the SPV error and the SPV range were significantly larger and more ipsilesionally tilted in the pusher group than in the other two groups. There was a significant correlation between the SPV error in the roll plane and the BLS score. CONCLUSIONS: The study revealed that patients with pusher behavior had an ipsilesional SPV tilt that decreased with decreasing severity of the behavior. The large uncertainty in verticality estimation in both planes indicates that their sensitivity for the perception of verticality in space is generally disturbed. These findings emphasize the importance of specific rehabilitation approaches to recalibrate the impaired inner model of verticality.

Functional electrical stimulation-assisted active cycling--therapeutic effects in patients with hemiparesis from 7 days to 6 months after stroke: a randomized controlled pilot study.

OBJECTIVE: To determine whether functional electrical stimulation (FES)-assisted active cycling is more effective than active cycling without FES concerning walking and balance. Specifically, walking ability was classified as to the amount of personal assistance needed to be able to walk and balance was evaluated for static and dynamic balance tasks. DESIGN: Monocentric, randomized, single-blinded, controlled trial. SETTING: Neurologic rehabilitation hospital. PARTICIPANTS: Patients with severe hemiparesis due to stroke (N=40). INTERVENTIONS: Twenty minutes of active leg cycling with or without FES applied to the paretic vastus medialis and rectus femoris of quadriceps and to the biceps femoris and semitendinosus muscles, 3 times/wk for 4 weeks. MAIN OUTCOME MEASURES: Functional ambulation classification (FAC) and performance-oriented mobility assessment (POMA) were the primary outcome measures. The leg subscale of the motricity index (MI) and the modified Ashworth scale were the secondary outcome measures. Evaluation was done before and after the intervention period and after an additional 2 weeks. RESULTS: After the intervention, the FAC, POMA, and the MI (P<.016) for both intervention groups improved significantly. The FAC of the control group increased by a median of 1 category and that of the FES group by 2 categories. The median change in POMA was 2 and 4 points for the control group and the FES group, respectively. The Mann-Whitney U test between-group comparisons revealed that these gains were significantly better in the FES group for both the FAC (U=90; z=-2.58; P=.013; r=-.42) and the POMA (U=60; z=-3.43; P<.0004; r=-.56). Because of missing data and slightly decreased effect sizes during the follow-up phase (FAC, r=-.33; POMA, r=-.41), differences did not reach statistically significant P values. The MI leg subscale showed significant improvements in both groups. However, there were no significant differences between the groups at any time. No changes were observed on the modified Ashworth scale. CONCLUSIONS: FES-assisted active cycling seems to be a promising intervention during rehabilitation in patients with stroke.

The Development of Neuroendocrine Disturbances over Time: Longitudinal Findings in Patients after Traumatic Brain Injury and Subarachnoid Hemorrhage.

Previous reports suggest that neuroendocrine disturbances in patients with traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH) may still develop or resolve months or even years after the trauma. We investigated a cohort of n = 168 patients (81 patients after TBI and 87 patients after SAH) in whom hormone levels had been determined at various time points to assess the course and pattern of hormonal insufficiencies. Data were analyzed using three different criteria: (1) patients with lowered basal laboratory values; (2) patients with lowered basal laboratory values or the need for hormone replacement therapy; (3) diagnosis of the treating physician. The first hormonal assessment after a median time of three months after the injury showed lowered hormone laboratory test results in 35% of cases. Lowered testosterone (23.1% of male patients), lowered estradiol (14.3% of female patients) and lowered insulin-like growth factor I (IGF-I) values (12.1%) were most common. Using Criterion 2, a higher prevalence rate of 55.6% of cases was determined, which correlated well with the prevalence rate of 54% of cases using the physicians' diagnosis as the criterion. Intraindividual changes (new onset insufficiency or recovery) were predominantly observed for the somatotropic axis (12.5%), the gonadotropic axis in women (11.1%) and the corticotropic axis (10.6%). Patients after TBI showed more often lowered IGF-I values at first testing, but normal values at follow-up (p < 0.0004). In general, most patients remained stable. Stable hormone results at follow-up were obtained in 78% (free thyroxine (fT4) values) to 94.6% (prolactin values).

Effects of repetitive peripheral magnetic stimulation on upper-limb spasticity and impairment in patients with spastic hemiparesis: a randomized, double-blind, sham-controlled study.

OBJECTIVE: To investigate short-term and long-term effects of repetitive peripheral magnetic stimulation (rpMS) on spasticity and motor function. DESIGN: Monocentric, randomized, double-blind, sham-controlled trial. SETTING: Neurologic rehabilitation hospital. PARTICIPANTS: Patients (N=66) with severe hemiparesis and mild to moderate spasticity resulting from a stroke or a traumatic brain injury. The average time ± SD since injury for the intervention groups was 26 ± 71 weeks or 37 ± 82 weeks. INTERVENTIONS: rpMS for 20 minutes or sham stimulation with subsequent occupational therapy for 20 minutes, 2 times a day, over a 2-week period. MAIN OUTCOME MEASURES: Modified Tardieu Scale and Fugl-Meyer Assessment (arm score), assessed before therapy, at the end of the 2-week treatment period, and 2 weeks after study treatment. Additionally, the Tardieu Scale was assessed after the first and before the third therapy session to determine any short-term effects. RESULTS: Spasticity (Tardieu >0) was present in 83% of wrist flexors, 62% of elbow flexors, 44% of elbow extensors, and 10% of wrist extensors. Compared with the sham stimulation group, the rpMS group showed short-term effects on spasticity for wrist flexors (P=.048), and long-term effects for elbow extensors (P<.045). Arm motor function (rpMS group: median 5 [4-27]; sham group: median 4 [4-9]) did not significantly change over the study period in either group, whereas rpMS had a positive effect on sensory function. CONCLUSIONS: Therapy with rpMS increases sensory function in patients with severe limb paresis. The magnetic stimulation, however, has limited effect on spasticity and no effect on motor function.

Inconsistent classification of pusher behaviour in stroke patients: a direct comparison of the Scale for Contraversive Pushing and the Burke Lateropulsion Scale.

OBJECTIVE: To compare the classification of two clinical scales for assessing pusher behaviour in a cohort of stroke patients. DESIGN: Observational case-control study. SETTING: Inpatient stroke rehabilitation unit. SUBJECTS: A sample of 23 patients with hemiparesis due to a unilateral stroke (1.6 ± 0.7 months post stroke). METHODS: Immediately before and after three different interventions, the Scale for Contraversive Pushing and the Burke Lateropulsion Scale were applied in a standardized procedure. RESULTS: The diagnosis of pusher behaviour on the basis of the Scale for Contraversive Pushing and the Burke Lateropulsion Scale differed significantly (χ2 = 54.260, p < 0.001) resulting in inconsistent classifications in 31 of 138 cases. Changes immediately after the interventions were more often detected by the Burke Lateropulsion Scales than by the Scale for Contraversive Pushing (χ2 = 19.148, p < 0.001). All cases with inconsistent classifications showed no pusher behaviour on the Scale for Contraversive Pushing, but pusher behaviour on the Burke Lateropulsion Scale. 64.5% (20 of 31) of them scored on the Burke Lateropulsion Scale on the standing and walking items only. CONCLUSIONS: The Burke Lateropulsion Scale is an appropriate alternative to the widely used Scale for Contraversive Pushing to follow-up patients with pusher behaviour (PB); it might be more sensitive to detect mild pusher behaviour in standing and walking.

The assistive potential of functional electrical stimulation to support object manipulation in functional upper extremity movements after stroke: A randomized cross-over study.

Background: After standard care, 55%-75% of patients after stroke show a persistent paresis of the upper limb (UL). Assistive devices are developed to increase the patients' level of independence in daily life. Objectives: To investigate the potential of Functional Electrical Stimulation (FES) to assist object manipulation in activities of daily life. Design: Seventeen patients after stroke were tested and analyzed in a randomized cross-over design. Methods: Functional grasping was assessed by means of the Action Research Arm Test (ARAT) and the modified Box and Block Test (mBBT), in one session with and another without FES assistance. The order of sessions was randomized. Patients' motivation was assessed after each session. Task performance and motivation were compared between conditions using the Wilcoxon test and subgroup analyses were performed for impairment severity by distribution-based mixed-factor analyses. Results: When analyzing the total ARAT, FES did not effectively assist the overall performance (P = .142), but did assist the performance of objects of the Grasp category (P = .020). Impairment severity showed an interaction with the orthotic effect (P = .012), as severely impaired patients profited from FES assistance and mild-moderately impaired did not. When focusing on the more functional items of the ARAT (i.e., excluding scores from thumb-middle and thumb-ring finger combinations), there was a significant orthotic effect of FES on task performance (P = .023). Further, there was an orthotic effect for the number of transported blocks in the mBBT (P = .033), exclusively prominent in the group of severely impaired patients. Functional Electrical Stimulation did not increase the patients' motivation (P = .959), which was high after both conditions. Conclusion: Functional Electrical Stimulation has the potential to support object manipulation, but is dependent on impairment severity and object type. To observe a consistent orthotic effect, features of the stimulator should be further developed to generate appropriate grasps and forces across subjects and objects. Trial Registration: The trial was registered with the German Clinical Trials Register (DRKS00025889).

Increased dual-task interference during upper limb movements in stroke exceeding that found in aging - a systematic review and meta-analysis.

Objective: To determine whether dual-task interference during upper limb tasks is increased in patients after stroke compared to healthy older subjects and to compare magnitude of stroke-induced change in interference to that explained by aging. Methods: We conducted a systematic literature search in MEDLINE, CINAHL, Google Scholar and PEDro databases up to October 2023 for studies on upper limb dual-tasks in stroke and elderly healthy subjects. Eleven upper limb dual-task studies in stroke patients and 11 studies in healthy older subjects were identified and systematically reviewed. A meta-analysis was performed on seven stroke studies and on five studies in healthy older subjects that included control groups. Results: Most stroke studies investigated proximal arm movements with kinematic measures, but few studies evaluated manual dexterity. In contrast, studies in healthy older subjects used more distal (finger tapping) tasks. The meta-analysis showed that stroke patients had on average a 19% (CI 95% = 1.0-37.3) increase in dual-task interference compared to age-matched healthy controls (Z = 2.06, p = 0.04). Older healthy subjects showed greater dual-task interference compared to younger subjects (19% greater, CI 95% = 6.5-31.2, Z = 2.98, p = 0.003). Conclusion: Meta-analysis revealed an increase in dual-task interference during upper limb movements in stroke patients, exceeding age-related changes, supporting the presence of subclinical impairments in divided attention post-stroke that may impede motor recovery.

Effects of a predefined mini-trampoline training programme on balance, mobility and activities of daily living after stroke: a randomized controlled pilot study.

OBJECTIVE: To investigate the effects of a predefined mini-trampoline therapy programme for increasing postural control, mobility and the ability to perform activities of daily living after stroke. DESIGN: Randomized non-blinded controlled pilot study. SETTING: Neurological rehabilitation hospital. SUBJECTS: First-time stroke; age 18-80 years; independent standing ability for a minimum of 2 minutes. INTERVENTION: Patients were randomized into two groups: the mini-trampoline group (n = 20) received 10 sessions of balance training using the mini-trampoline over three weeks. The patients of the control group (n =20) participated 10 times in a group balance training also over three weeks. MAIN MEASURES: Postural control (Berg Balance Scale, BBS), mobility and gait endurance (timed 'up and go' test, TUG; 6-minute walk test, 6MWT) and the ability to perform activities of daily living (Barthel Index, BI). Measurements were undertaken prior to and after the intervention period. RESULTS: Both groups were comparable before the study. The mini-trampoline group improved significantly more in the BBS (P = 0.003) compared to the control group. Mean or median differences of both groups showed improvements in the TUG 10.12 seconds/7.23 seconds, the 6MWT 135 m/75 m and the BI 20 points/13 points for the mini-trampoline and control group, respectively. These outcome measurements did not differ significantly between the two groups. CONCLUSION: A predefined mini-trampoline training programme resulted in significantly increased postural control in stroke patients compared to balance training in a group. Although not statistically significant, the mini-trampoline training group showed increased improvement in mobility and activities of daily living. These differences could have been statistically significant if we had investigated more patients (i.e. a total sample of 84 patients for the TUG, 98 patients for the 6MWT, and 186 patients for the BI).

Time course and influence of pusher behavior on outcome in a rehabilitation setting: a prospective cohort study.

OBJECTIVE: To examine the prevalence and the time course of pusher behavior (PB) among patients with hemiparesis in a rehabilitation setting and the influence of this behavior on rehabilitation outcome. METHODS: Over a 1-year period, 448 inpatients with hemiparesis after stroke and nonstroke etiologies were screened in the first week after admission to a neurological rehabilitation hospital. The Clinical Scale for Contraversive Pushing was used to differentiate pusher from nonpusher patients. If PB was present, the patient was examined weekly. The prevalence and duration of PB was assessed, and influence on rehabilitation efficiency and effectiveness according to the Motor Function Assessment Scale and Barthel Index was calculated. RESULTS: PB was present in 16% of all examined, in 17% of the stroke patients, and in 31% of patients (33% of stroke patients) unable to stand erect without support. PB duration within the rehabilitation hospital was 5 ± 4.3 weeks (median = 4; range, 1-20). PB is a negative predictor for the rehabilitation outcome: PB patients are only half as efficient and effective as nonpusher patients. The effect worsened if PB had been present for a longer period of time. CONCLUSION: The prevalence of PB and its influence on rehabilitation outcome reveal PB as a relevant disorder in stroke rehabilitation. However, the duration of the behavior differed widely among the PB patients. Further studies are needed to establish prognostic criteria for identifying patients with a potential for developing long-term PB.

Contralaterally EMG-triggered functional electrical stimulation during serious gaming for upper limb stroke rehabilitation: a feasibility study.

Introduction: Virtual Reality/serious games (SG) and functional electrical stimulation (FES) therapies are used in upper limb stroke rehabilitation. A combination of both approaches seems to be beneficial for therapy success. The feasibility of a combination of SG and contralaterally EMG-triggered FES (SG+FES) was investigated as well as the characteristics of responders to such a therapy. Materials and methods: In a randomized crossover trial, patients performed two gaming conditions: SG alone and SG+FES. Feasibility of the therapy system was assessed using the Intrinsic Motivation Inventory (IMI), the Nasa Task Load Index, and the System Usability Scale (SUS). Gaming parameters, fatigue level and a technical documentation was implemented for further information. Results: In total, 18 patients after stroke (62.1 ± 14.1 years) with a unilateral paresis of the upper limb (MRC ≤4) were analyzed in this study. Both conditions were perceived as feasible. Comparing the IMI scores between conditions, perceived competence was significantly increased (z = -2.88, p = 0.004) and pressure/tension during training (z = -2.13, p = 0.034) was decreased during SG+FES. Furthermore, the task load was rated significantly lower for the SG+FES condition (z = -3.14, p = 0.002), especially the physical demand (z = -3.08, p = 0.002), while the performance was rated better (z = -2.59, p = 0.010). Responses to the SUS and the perceived level of fatigue did not differ between conditions (SUS: z = -0.79, p = 0.431; fatigue: z = 1.57, p = 0.115). For patients with mild to moderate impairments (MRC 3-4) the combined therapy provided no or little gaming benefit. The additional use of contralaterally controlled FES (ccFES), however, enabled severely impaired patients (MRC 0-1) to play the SG. Discussion: The combination of SG with ccFES is feasible and well-accepted among patients after stroke. It seems that the additional use of ccFES may be more beneficial for severely impaired patients as it enables the execution of the serious game. These findings provide valuable implications for the development of rehabilitation systems by combining different therapeutic interventions to increase patients' benefit and proposes system modifications for home use. Clinical trial registration: https://drks.de/search/en, DRKS00025761.

Online detection of compensatory strategies in human movement with supervised classification: a pilot study.

Introduction: Stroke survivors often compensate for the loss of motor function in their distal joints by altered use of more proximal joints and body segments. Since this can be detrimental to the rehabilitation process in the long-term, it is imperative that such movements are indicated to the patients and their caregiver. This is a difficult task since compensation strategies are varied and multi-faceted. Recent works that have focused on supervised machine learning methods for compensation detection often require a large training dataset of motions with compensation location annotations for each time-step of the recorded motion. In contrast, this study proposed a novel approach that learned a linear classifier from energy-based features to discriminate between healthy and compensatory movements and identify the compensating joints without the need for dense and explicit annotations. Methods: Six healthy physiotherapists performed five different tasks using healthy movements and acted compensations. The resulting motion capture data was transformed into joint kinematic and dynamic trajectories. Inspired by works in bio-mechanics, energy-based features were extracted from this dataset. Support vector machine (SVM) and logistic regression (LR) algorithms were then applied for detection of compensatory movements. For compensating joint identification, an additional condition enforcing the independence of the feature calculation for each observable degree of freedom was imposed. Results: Using leave-one-out cross validation, low values of mean brier score (<0.15), mis-classification rate (<0.2) and false discovery rate (<0.2) were obtained for both SVM and LR classifiers. These methods were found to outperform deep learning classifiers that did not use energy-based features. Additionally, online classification performance by our methods were also shown to outperform deep learning baselines. Furthermore, qualitative results obtained from the compensation joint identification experiment indicated that the method could successfully identify compensating joints. Discussion: Results from this study indicated that including prior bio-mechanical information in the form of energy based features can improve classification performance even when linear classifiers are used, both for offline and online classification. Furthermore, evaluation compensation joint identification algorithm indicated that it could potentially provide a straightforward and interpretable way of identifying compensating joints, as well as the degree of compensation being performed.

Hybrid Functional Electrical Stimulation and Robotic Assistance for Wrist Motion Training After Stroke: Preliminary Results.

This work presents preliminary results of a clinical study with sub-acute stroke patients using a hybrid system for wrist rehabilitation. The patients trained their wrist flexion/extension motion through a target tracking task, where electrical stimulation and robotic torque assisted them proportionally to their tracking error. Five sub-acute stroke patients have completed the training for 3 sessions on separate days. The preliminary results show hybrid assistance improves tracking performance and motion smoothness in most participants. In each session, patients' tracking performances before and after training were evaluated in unassisted tracking trials, without assistance. Their unassisted performance was compared across sessions and the results suggest that moderately to severely impaired patients might benefit more from hybrid training with our system than mildly impaired patients. Subjective assessments from all sessions show that the patients found the use of the device very comfortable and the training enjoyable. More data is being collected and future work will aim at verifying these trends.

Validation of a mechanism to balance exercise difficulty in robot-assisted upper-extremity rehabilitation after stroke.

BACKGROUND: The motivation of patients during robot-assisted rehabilitation after neurological disorders that lead to impairments of motor functions is of great importance. Due to the increasing number of patients, increasing medical costs and limited therapeutic resources, clinicians in the future may want patients to practice their movements at home or with reduced supervision during their stay in the clinic. Since people only engage in an activity and are motivated to practice if the outcome matches the effort at which they perform, an augmented feedback application for rehabilitation should take the cognitive and physical deficits of patients into account and incorporate a mechanism that is capable of balancing i.e. adjusting the difficulty of an exercise in an augmented feedback application to the patient's capabilities. METHODS: We propose a computational mechanism based on Fitts' Law that balances i.e. adjusts the difficulty of an exercise for upper-extremity rehabilitation. The proposed mechanism was implemented into an augmented feedback application consisting of three difficulty conditions (easy, balanced, hard). The task of the exercise was to reach random targets on the screen from a starting point within a specified time window. The available time was decreased with increasing condition difficulty. Ten subacute stroke patients were recruited to validate the mechanism through a study. Cognitive and motor functions of patients were assessed using the upper extremity section of the Fugl-Meyer Assessment, the modified Ashworth scale as well as the Addenbrookes cognitive examination-revised. Handedness of patients was obtained using the Edinburgh handedness inventory. Patients' performance during the execution of the exercises was measured twice, once for the paretic and once for the non-paretic arm. Results were compared using a two-way ANOVA. Post hoc analysis was performed using a Tukey HSD with a significance level of p < 0.05. RESULTS: Results show that the mechanism was capable of balancing the difficulty of an exercise to the capabilities of the patients. Medians for both arms show a gradual decrease and significant difference of the number of successful trials with increasing condition difficulty (F(2;60) = 44.623; p < 0.01; η(2) = 0.623) but no significant difference between paretic and non-paretic arm (F(1;60) = 3.768; p = 0.057; η(2) = 0.065). Post hoc analysis revealed that, for both arms, the hard condition significantly differed from the easy condition (p < 0.01). In the non-paretic arm there was an additional significant difference between the balanced and the hard condition (p < 0.01). Reducing the time to reach the target, i.e., increasing the difficulty level, additionally revealed significant differences between conditions for movement speeds (F(2;59) = 6.013; p < 0.01; η(2) = 0.185), without significant differences for hand-closing time (F(2;59) = 2.620; p = 0.082; η(2) = 0.09), reaction time (F(2;59) = 0.978; p = 0.383; η(2) = 0.036) and hand-path ratio (F(2;59) = 0.054; p = 0.947; η(2) = 0.002). The evaluation of a questionnaire further supported the assumption that perceived performance declined with increased effort and increased exercise difficulty leads to frustration. CONCLUSIONS: Our results support that Fitts' Law indeed constitutes a powerful mechanism for task difficulty adaptation and can be incorporated into exercises for upper-extremity rehabilitation.

The scale for retropulsion: Internal consistency, reliability and construct validity.

BACKGROUND: Retropulsion is an impairment of body orientation against gravity in the sagittal plane. In a Delphi study, the Scale for Retropulsion (SRP) was developed with a high level of expert agreement. OBJECTIVE: To assess the clinimetric properties of the German SRP in patients with neurological disorders. METHODS: The SRP was applied to 70 hospitalized patients with neurological disorders (stroke, critical illness neuropathy and/or myopathy, Parkinson syndromes). Internal consistency was determined with the Cronbach ɑ. Test-retest and interrater reliabilities were evaluated with the weighted kappa, intraclass correlation coefficient (ICC), and Bland-Altman plots. The construct validity was evaluated with Spearman correlation. RESULTS: The median (interquartile range) SRP score was 5 (3-8) and ranged from 0 to 22 (total scale range: 0 to 24). The SRP had excellent internal consistency (Cronbach ɑ=0.875) and good to excellent test-retest reliability (weighted kappa=0.957, ICC=0.957) and interrater reliability (weighted kappa=0.837, ICC=0.837). Analysis of construct validity resulted in good correlations with other clinical balance scales (rSp>0.80), and fair to moderate correlations with posturographic measures (rSp=0.27-0.56) and the subjective postural vertical error in the sagittal plane (rSp=-0.325, P=0.012) as well as the range in the frontal plane (rSp=0.359, P=0.007). The SRP discriminated between patients classified with and without retropulsion by an independent clinical expert (P<0.001). CONCLUSION: The SRP provides a valid and reliable bedside test to quantify retropulsion in individuals with neurological disorders.

Influence of footwear on postural sway: A systematic review and meta-analysis on barefoot and shod bipedal static posturography in patients and healthy subjects.

BACKGROUND: Bipedal static posturography is widely used to assess postural control. However, standardized methods and evidence on the influence of footwear on balance in comparison to barefoot stance is sparse. RESEARCH QUESTIONS: Is bipedal static posturography applied in a standardized way with respect to demographics and the experimental set-up (systematic review)? Does habitual footwear influence postural control in comparison to barefoot condition during bipedal static posturography in adult patients and healthy subjects (meta-analysis)? METHODS: For this systematic review and meta-analysis, a comprehensive follow-up literature search was conducted from March 2009 until January 2020 according to the PRISMA guidelines. Original, research articles reporting on bipedal, unsupported, static posturography in adults (≥18 years) were included according to inclusion criteria (age, sex, height, weight, duration, repetitions, visual/foot condition, sampling frequency). Studies comparing habitual footwear with barefoot condition during bipedal static posturography were included for the meta-analysis. Center of pressure parameters (sway velocity, range, root mean square, paths lengths) with subjects having eyes closed (EC) or open (EO) were analyzed using random effects models. RESULTS: For this systematic review and meta-analysis, 207 and eight out of 5189 studies with 12'341 and 156 subjects, respectively, were eligible. Most studies (89%) reported barefoot, 5% shod, and 6% barefoot and shod measurements. Less than half of studies (44%) included patients of which the minority (13%) suffered from neurological disease. Sway velocity in the anterior-posterior direction was higher in habitual shoes compared to barefoot with EC (SMD: 1.08; 95% CI: 0.68-1.48; p < 0.01; I2 = 0%), with EO (SMD: 0.68; 95% CI: 0.11-1.26; p = 0.02; I2 = 1%), and in the medio-lateral direction with EC (SMD: 1.30; 95% CI: 0.76-1.85, p < 0.01; I2 = 37%). SIGNIFICANCE: Methodical heterogeneity of bipedal static posturography hampers studies' comparability. Thus, we provide a standardized approach to increase knowledge whether habitual footwear decrease postural control in comparison to barefoot stance.