Validity and reliability of the chronic composite XA, an upper limb motor assessment using Active Range of Motion in patients with chronic stroke.

BACKGROUND: Upper limb (UL) spastic paresis has been classically evaluated with assessments of passive movements with limited functional validity. The aim of this study was to assess whether a composite measure of active range of motion (AROM, or XA) is valid and reliable in chronic post-stroke spastic paresis. AIM: The primary objective was to investigate the validity and reliability of a composite score, comprising multiple XA measurements, to assess UL spastic paresis in patients in chronic stages post-stroke. In addition to this, an exploratory analysis was conducted to identify which muscles should be optimally included in this composite score. DESIGN: A psychometric proprieties study. SETTING: Physical and Rehabilitation Medicine Department. POPULATION: twenty-eight chronic post-stroke participants with spastic paresis. METHODS: Composite UL XA measurement in twenty-eight chronic post-stroke participants (age=59±11 years; delay post-stroke=29±37 months) with spastic paresis was repeated twice about 40 days apart in a standardized body position. Concurrent and construct validity was evaluated exploring correlation with the Fugl-Meyer Assessment Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), and grip strength (JAMAR™). Reliability was assessed by calculating intraclass correlation coefficients (ICC). Regarding the exploratory analysis, a linear regression analysis was performed to examine the value of including various muscles. RESULTS: Composite XA against the resistance of elbow, wrist and finger flexors showed strong correlation with FMA-UE and ARAT (r=0.88; P<0.001 and r=0.82; P<0.001 respectively) and a weak association with grip strength (r=0.43; P=0.03). Test-retest reliability was excellent (ICC=0.92). However, the most effective regression model also included XA against the resistance of shoulder adductors as well as forearm pronator (adjusted R2=0.85; AIC=170). CONCLUSIONS: The present study provided satisfactory psychometric data for the upper limb composite active movement (CXA), derived from the Five Step Assessment. For overall measurement of UL mobility after stroke, we strongly recommend including shoulder and forearm muscles to the score. CLINICAL REHABILITATION IMPACT: Composite XA is a valid and reliable measure of upper limb motor function in chronic post-stroke patients and could be used in clinical practice and research.

Toward an Adapted Neurofeedback for Post-stroke Motor Rehabilitation: State of the Art and Perspectives.

Stroke is a severe health issue, and motor recovery after stroke remains an important challenge in the rehabilitation field. Neurofeedback (NFB), as part of a brain-computer interface, is a technique for modulating brain activity using on-line feedback that has proved to be useful in motor rehabilitation for the chronic stroke population in addition to traditional therapies. Nevertheless, its use and applications in the field still leave unresolved questions. The brain pathophysiological mechanisms after stroke remain partly unknown, and the possibilities for intervention on these mechanisms to promote cerebral plasticity are limited in clinical practice. In NFB motor rehabilitation, the aim is to adapt the therapy to the patient's clinical context using brain imaging, considering the time after stroke, the localization of brain lesions, and their clinical impact, while taking into account currently used biomarkers and technical limitations. These modern techniques also allow a better understanding of the physiopathology and neuroplasticity of the brain after stroke. We conducted a narrative literature review of studies using NFB for post-stroke motor rehabilitation. The main goal was to decompose all the elements that can be modified in NFB therapies, which can lead to their adaptation according to the patient's context and according to the current technological limits. Adaptation and individualization of care could derive from this analysis to better meet the patients' needs. We focused on and highlighted the various clinical and technological components considering the most recent experiments. The second goal was to propose general recommendations and enhance the limits and perspectives to improve our general knowledge in the field and allow clinical applications. We highlighted the multidisciplinary approach of this work by combining engineering abilities and medical experience. Engineering development is essential for the available technological tools and aims to increase neuroscience knowledge in the NFB topic. This technological development was born out of the real clinical need to provide complementary therapeutic solutions to a public health problem, considering the actual clinical context of the post-stroke patient and the practical limits resulting from it.

Visual feedback improves movement illusions induced by tendon vibration after chronic stroke.

BACKGROUND: Illusion of movement induced by tendon vibration is commonly used in rehabilitation and seems valuable for motor rehabilitation after stroke, by playing a role in cerebral plasticity. The aim was to study if congruent visual cues using Virtual Reality (VR) could enhance the illusion of movement induced by tendon vibration of the wrist among participants with stroke. METHODS: We included 20 chronic stroke participants. They experienced tendon vibration of their wrist (100 Hz, 30 times) inducing illusion of movement. Three VR visual conditions were added to the vibration: a congruent moving virtual hand (Moving condition); a static virtual hand (Static condition); or no virtual hand at all (Hidden condition). The participants evaluated for each visual condition the intensity of the illusory movement using a Likert scale, the sensation of wrist's movement using a degree scale and they answered a questionnaire about their preferred condition. RESULTS: The Moving condition was significantly superior to the Hidden condition and to the Static condition in terms of illusion of movement (p < 0.001) and the wrist's extension (p < 0.001). There was no significant difference between the Hidden and the Static condition for these 2 criteria. The Moving condition was considered the best one to increase the illusion of movement (in 70% of the participants). Two participants did not feel any illusion of movement. CONCLUSIONS: This study showed the interest of using congruent cues in VR in order to enhance the consistency of the illusion of movement induced by tendon vibration among participants after stroke, regardless of their clinical severity. By stimulating the brain motor areas, this visuo-proprioceptive feedback could be an interesting tool in motor rehabilitation. Record number in Clinical Trials: NCT04130711, registered on October 17th 2019 ( https://clinicaltrials.gov/ct2/show/NCT04130711?id=NCT04130711&draw=2&rank=1 ).

Influence of the visuo-proprioceptive illusion of movement and motor imagery of the wrist on EEG cortical excitability among healthy participants.

INTRODUCTION: Motor Imagery (MI) is a powerful tool to stimulate sensorimotor brain areas and is currently used in motor rehabilitation after a stroke. The aim of our study was to evaluate whether an illusion of movement induced by visuo-proprioceptive immersion (VPI) including tendon vibration (TV) and Virtual moving hand (VR) combined with MI tasks could be more efficient than VPI alone or MI alone on cortical excitability assessed using Electroencephalography (EEG). METHODS: We recorded EEG signals in 20 healthy participants in 3 different conditions: MI tasks involving their non-dominant wrist (MI condition); VPI condition; and VPI with MI tasks (combined condition). Each condition lasted 3 minutes, and was repeated 3 times in randomized order. Our main judgment criterion was the Event-Related De-synchronization (ERD) threshold in sensori-motor areas in each condition in the brain motor area. RESULTS: The combined condition induced a greater change in the ERD percentage than the MI condition alone, but no significant difference was found between the combined and the VPI condition (p = 0.07) and between the VPI and MI condition (p = 0.20). CONCLUSION: This study demonstrated the interest of using a visuo-proprioceptive immersion with MI rather than MI alone in order to increase excitability in motor areas of the brain. Further studies could test this hypothesis among patients with stroke to provide new perspectives for motor rehabilitation in this population.

WITHDRAWN: Alternative bimodal unimodal neurofeedback training to induce cerebral reorganization after chronic stroke: A proof-of-concept case report.

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Influence of virtual reality visual feedback on the illusion of movement induced by tendon vibration of wrist in healthy participants.

INTRODUCTION: Illusion of movement induced by tendon vibration is an effective approach for motor and sensory rehabilitation in case of neurological impairments. The aim of our study was to investigate which modality of visual feedback in Virtual Reality (VR) associated with tendon vibration of the wrist could induce the best illusion of movement. METHODS: We included 30 healthy participants in the experiment. Tendon vibration inducing illusion of movement (wrist extension, 100Hz) was applied on their wrist during 3 VR visual conditions (10 times each): a moving virtual hand corresponding to the movement that the participants could feel during the tendon vibration (Moving condition), a static virtual hand (Static condition), or no virtual hand at all (Hidden condition). After each trial, the participants had to quantify the intensity of the illusory movement on a Likert scale, the subjective degree of extension of their wrist and afterwards they answered a questionnaire. RESULTS: There was a significant difference between the 3 visual feedback conditions concerning the Likert scale ranking and the degree of wrist's extension (p<0.001). The Moving condition induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Hidden condition (p<0.001 and p<0.001 respectively) than that of the Static condition (p<0.001 and p<0.001 respectively). The Hidden condition also induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Static condition (p<0.01 and p<0.01 respectively). The preferred condition to facilitate movement's illusion was the Moving condition (63.3%). CONCLUSIONS: This study demonstrated the importance of carefully selecting a visual feedback to improve the illusion of movement induced by tendon vibration, and the increase of illusion by adding VR visual cues congruent to the illusion of movement. Further work will consist in testing the same hypothesis with stroke patients.

The effects of repetitive neck-muscle vibration on postural disturbances after a chronic stroke.

OBJECTIVE: We aimed to test a repeated program of vibration sessions of the neck muscles (rNMV) on postural disturbances and spatial perception in patients with right (RBD) versus left (LBD) vascular brain damage. METHODS: Thirty-two chronic stroke patients (mean age 60.9±10 yrs and mean time since stroke 4.9±4 yrs), 16 RBD and 16 LBD, underwent a program of 10 sessions of NMV over two weeks. Posturography parameters (weight-bearing asymmetry (WBA), Xm, Ym, and surface), balance rating (Berg Balance Scale (BBS), Timed Up and Go (TUG)), space representation (subjective straight ahead (SSA), longitudinal body axis (LBA), subjective visual vertical (SVV)), and post-stroke deficiencies (motricity index, sensitivity, and spasticity) were tested and the data analyzed by ANOVA or a linear rank-based model, depending on whether the data were normally distributed, with lesion side and time factor (D-15, D0, D15, D21, D45). RESULTS: The ANOVA revealed a significant interaction between lesion side and time for WBA (P<0.0001) with a significant shift towards the paretic lower limb in the RBD patients only (P=0.0001), whereas there was no effect in the LBD patients (P=0.98). Neither group showed a significant modification of spatial representation. Nonetheless, there was a significant improvement in motricity (P=0.02), TUG (P=0.0005), and BBS (P<0.0001) in both groups at the end of treatment and afterwards. CONCLUSIONS: rNMV appeared to correct WBA in RBD patients only. This suggests that rNMV could be effective in treating sustainable imbalance due to spatial cognition disorders.

A Multi-Target Motor Imagery Training Using Bimodal EEG-fMRI Neurofeedback: A Pilot Study in Chronic Stroke Patients.

Traditional rehabilitation techniques present limitations and the majority of patients show poor 1-year post-stroke recovery. Thus, Neurofeedback (NF) or Brain-Computer-Interface applications for stroke rehabilitation purposes are gaining increased attention. Indeed, NF has the potential to enhance volitional control of targeted cortical areas and thus impact on motor function recovery. However, current implementations are limited by temporal, spatial or practical constraints of the specific imaging modality used. In this pilot work and for the first time in literature, we applied bimodal EEG-fMRI NF for upper limb stroke recovery on four stroke-patients with different stroke characteristics and motor impairment severity. We also propose a novel, multi-target training approach that guides the training towards the activation of the ipsilesional primary motor cortex. In addition to fMRI and EEG outcomes, we assess the integrity of the corticospinal tract (CST) with tractography. Preliminary results suggest the feasibility of our approach and show its potential to induce an augmented activation of ipsilesional motor areas, depending on the severity of the stroke deficit. Only the two patients with a preserved CST and subcortical lesions succeeded in upregulating the ipsilesional primary motor cortex and exhibited a functional improvement of upper limb motricity. These findings highlight the importance of taking into account the variability of the stroke patients' population and enabled to identify inclusion criteria for the design of future clinical studies.