A functional magnetic resonance imaging study of visuomotor processing in a virtual reality-based paradigm: Rehabilitation Gaming System

Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia.Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test.Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06-0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group.Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

Redefining stroke rehabilitation: Mobilizing the embodied goal-oriented brain

Advancements in stroke rehabilitation remain limited and call for a reorientation. Based on recent results, this study proposes a network-centric perspective on stroke, positing that it not only causes localized deficits but also affects the brain's intricate network of networks, transiting it into a pathological state. Translating these system-level insights into interventions requires brain theory, and the Distributed Adaptive Control (DAC) theory offers such a framework. When applied in the rehabilitation gaming system, these principles demonstrate superior results over conventional methods. This impact stems from activating extensive brain networks, particularly the executive control network, focused motor learning, and maintaining excitatory-inhibitory balance, which is essential for neural repair and functional reorganization. The analysis stresses uniting preclinical and clinical research and placing the architecture of the embodied volitional brain at the centre of rehabilitation approaches.

Feasibility and usability of a virtual-reality-based sensorimotor activation apparatus for carpal tunnel syndrome patients

PURPOSE

This study aimed to assess the usability of a virtual reality-assisted sensorimotor activation (VRSMA) apparatus for individual digit rehabilitation. The study had two main objectives: Firstly, to collect preliminary data on the expectations and preferences of patients with carpal tunnel syndrome (CTS) regarding virtual reality (VR) and an apparatus-assisted therapy for their affected digits. Secondly, to evaluate the usability of the VRSMA apparatus that was developed.

METHODS

The VRSMA system consists of an apparatus that provides sensory and motor stimulation via a vibratory motor and pressure sensor attached to a button, and a virtual reality-based visual cue provided by texts overlaid on top of a 3D model of a hand. The study involved 10 CTS patients who completed five blocks of VRSMA with their affected hand, with each block corresponding to the five digits. The patients were asked to complete a user expectations questionnaire before experiencing the VRSMA, and a user evaluation questionnaire after completing the VRSMA. Expectations for VRSMA were obtained from the questionnaire results using a House of Quality (HoQ) analysis.

RESULTS

In the survey for expectations, participants rated certain attributes as important for a rehabilitation device for CTS, with mean ratings above 4 for attributes such as ease of use, ease of understanding, motivation, and improvement of hand function based on clinical evidence. The level of immersion and an interesting rehabilitation regime received lower ratings, with mean ratings above 3.5. The survey evaluating VRSMA showed that the current prototype was overall satisfactory with a mean rating of 3.9 out of 5. Based on the HoQ matrix, the highest priority for development of the VRSMA was to enhance device comfort and usage time. This was followed by the need to perform more clinical studies to provide evidence of the efficacy of the VRSMA. Other technical characteristics, such as VRSMA content and device reliability, had lower priority scores.

CONCLUSION

The current study presents a potential for an individual digit sensorimotor rehabilitation device that is well-liked by CTS patients.

Development of Immersive Virtual Reality-Based Hand Rehabilitation System Using a Gesture-Controlled Rhythm Game With Vibrotactile Feedback: An fNIRS Pilot Study

Recently, virtua reality (VR) has been widely utilized with rehabilitation to promote user engagement, which has been shown to induce brain plasticity. In this study, we developed a VR-based hand rehabilitation system consisting of a personalized gesture-controlled rhythm game with vibrotactile feedback and investigated the cortical activation pattern induced by our system using functional near-infrared spectroscopy (fNIRS). Our system provides vibrotactile feedback as the user matches their hand gestures to VR targets customized to their pre-recorded hand gestures. Cortical activation was measured via fNIRS during 420 seconds of alternating gameplay and rest in 11 healthy subjects and one stroke survivor. Regions of interest (ROI) were the prefrontal cortex (PFC), the premotor cortex & the supplementary motor area (PMC&SMA), the primary sensorimotor cortex (SM1), and the somatosensory association cortex (SAC). The mean success rate of gesture matching among healthy subjects was 90 % with a standard deviation of 10.7 %, and the success rate of the stroke survivor was 79.6 %. The averaged cortical activation map for the 11 healthy subjects and the individual cortical activation map for the single stroke survivor showed increased hemodynamic responses of oxygenated hemoglobin (HbO) during the VR-based hand rehabilitation compared to the resting condition. Paired t-test analysis demonstrated a significant increase in HbO activation values in 19 out of 51 channels, corresponding to all ROIs except the left PFC and PMC&SMA, which exhibited high subject variability. The experimental results indicate that the proposed system successfully activated brain areas related to motor planning/execution, multisensory integration, and attention.

Multiscale effects of excitatory-inhibitory homeostasis in lesioned cortical networks: A computational study

Stroke-related disruptions in functional connectivity (FC) often spread beyond lesioned areas and, given the localized nature of lesions, it is unclear how the recovery of FC is orchestrated on a global scale. Since recovery is accompanied by long-term changes in excitability, we propose excitatory-inhibitory (E-I) homeostasis as a driving mechanism. We present a large-scale model of the neocortex, with synaptic scaling of local inhibition, showing how E-I homeostasis can drive the post-lesion restoration of FC and linking it to changes in excitability. We show that functional networks could reorganize to recover disrupted modularity and small-worldness, but not network dynamics, suggesting the need to consider forms of plasticity beyond synaptic scaling of inhibition. On average, we observed widespread increases in excitability, with the emergence of complex lesion-dependent patterns related to biomarkers of relevant side effects of stroke, such as epilepsy, depression and chronic pain. In summary, our results show that the effects of E-I homeostasis extend beyond local E-I balance, driving the restoration of global properties of FC, and relating to post-stroke symptomatology. Therefore, we suggest the framework of E-I homeostasis as a relevant theoretical foundation for the study of stroke recovery and for understanding the emergence of meaningful features of FC from local dynamics.

Left or right ear? A neuroimaging study using combined taVNS/fMRI to understand the interaction between ear stimulation target and lesion location in chronic stroke

BACKGROUND

Implanted vagus nerve stimulation (VNS) and transcutaneous auricular VNS (taVNS) have been primarily administered clinically to the unilateral-left vagus nerve. This left-only convention has proved clinically beneficial in brain disorders. However, in stroke survivors, the presence of a lesion in the brain may complicate VNS-mediated signaling, and it is important to understand the laterality effects of VNS in stroke survivors to optimize the intervention.

OBJECTIVE

To understand whether taVNS delivered to different ear targets relative to the lesion (ipsilesional vs contralesional vs bilateral vs sham) impacts blood oxygenation level dependent (BOLD) signal propagation in stroke survivors.

METHODS

We enrolled 20 adults with a prior history of stroke. Each participant underwent a single visit, during which taVNS was delivered concurrently during functional magnetic resonance imaging (fMRI) acquisition. Each participant received three discrete active stimulation conditions (ipsilesional, contralesional, bilateral) and one sham condition in a randomized order. Stimulation-related BOLD signal changes in the active conditions were compared to sham conditions to understand the interaction taVNS and laterality effects.

RESULTS

All active taVNS conditions deactivated the contralesional default mode network related regions compared to sham, however only ipsilesional taVNS enhanced the activations in the ipsilesional visuomotor and secondary visual cortex. Furthermore, we reveal an interaction in task activations between taVNS and cortical visuomotor areas, where ipsilesional taVNS significantly increased ipsilesional visuomotor activity and decreased contralesional visuomotor activity compared to sham.

CONCLUSION

Laterality of taVNS relative to the lesion is a critical factor in optimizing taVNS in a stroke population, with ipsilesional stimulation providing largest direct brain activation and should be explored further when designing taVNS studies in neurorehabilitation.

Investigating and acquiring motor expertise using virtual reality

After just months of simulated training, on January 19, 2019 a 23-year-old E-sports pro-gamer, Enzo Bonito, took to the racetrack and beat Lucas di Grassi, a Formula E and ex-Formula 1 driver with decades of real-world racing experience. This event raised the possibility that practicing in virtual reality can be surprisingly effective for acquiring motor expertise in real-world tasks. Here, we evaluate the potential of virtual reality to serve as a space for training to expert levels in highly complex real-world tasks in time windows much shorter than those required in the real world and at much lower financial cost without the hazards of the real world. We also discuss how VR can also serve as an experimental platform for exploring the science of expertise more generally.

Virtual Reality Exergaming Capability to Change Muscle Strategy During the Limits of Stability Test and Reduce Fear of Falling in Primary Osteoporotic Women

Objective: Muscle strength and balance impairment change the control strategy and increase the probability of falling. This study aimed to investigate the effect of 6-week strength-balance training through virtual reality exergaming (VRE) on muscle strategy during the limits of stability (LOS) test, fear of falling, and quality of life (QOL) in osteoporotic women. Materials and Methods: Twenty volunteer postmenopausal women with osteoporosis were randomly allocated to the VRE (n = 10) and traditional training (TRT as control, n = 10) groups. The VRE and TRT strength-balance training was performed for 6 weeks and three sessions per week. Before and after exercise, the muscle activity (onset time, peak root means square [PRMS]) and hip/ankle activity ratio were assessed by the wireless electromyography system. The muscle activities of the dominant leg were recorded during LOS functional test. The fall efficacy scale and QOL were assessed. Paired t-test was used to compare results within groups, and an independent t-test was used to compare the percentage changes in parameters between the two groups. Results: The VRE improved the onset time and PRMS. The VRE significantly reduced the hip/ankle activity ratio in the LOS test's forward, backward, and right directions (P < 0.05). No significant change was seen in all directions of the LOS functional test in the TRT group (P > 0.05). VRE reduced the fall efficacy scale (P = 0.042). Both VRT and TRT improved the total QOL score (P = 0.010). Conclusion: VRE was more effective in decreasing the onset time and hip/ankle ratio of muscle activation. The VRE is recommended to induce a better ability to reduce the fear of falling and control balance during functional activity in osteoporotic women. Clinical Trial Registration number: IRCT20101017004952N9.

Virtual reality does not fool the brain only: spinal excitability changes during virtually simulated falling

Virtual reality (VR) is known to induce substantial activation of brain's motor regions. It remains unclear to what extent virtual reality can trigger the sensorimotor system, and more particularly, whether it can affect lower nervous levels. In this study, we aimed to assess whether VR simulation of challenging and stressful postural situations (Richie's plank experience) could interfere with spinal excitability of postural muscles in 15 healthy young participants. The H-reflex of the triceps surae muscles was elicited with electrical nerve stimulation while participants were standing and wearing a VR headset. Participants went through several conditions, during which stimulations were evoked: standing still (noVR), standing in VR on the ground (groundVR), standing on the edge of a building (plankVR), and falling from the building (fallingVR). Myoelectrical activity of the triceps surae muscles was measured throughout the experiment. Leg and head movements were also measured by means of accelerometers to account for body oscillations. First, no differences in head rotations and myoelectrical activity were to be noted between conditions. Second, triceps H-reflex (H_MAX/M_MAX) was not affected from noVR to groundVR and plankVR. The most significant finding was a drastic decrease in H-reflex during falling (-47 ± 26.9% between noVR and fallingVR, P = 0.015). It is suggested that experiencing a postural threat in VR efficiently modulates spinal excitability, despite remaining in a quiet standing posture. This study suggests that simulated falling mimics the neural adjustments observed during actual postural challenge tasks.NEW & NOTEWORTHY The present study showed a modulation of spinal excitability induced by virtual reality (VR). In the standing position, soleus H-reflex was downmodulated during a simulated falling, in the absence of apparent changes in body oscillations. Since the same behavior is usually observed during real falling, it was suggested that the visual cues provided by VR were sufficiently strong to lead the neuromuscular system to mimic the actual modulation.

Examining the effectiveness of virtual, augmented, and mixed reality (VAMR) therapy for upper limb recovery and activities of daily living in stroke patients: a systematic review and meta-analysis

INTRODUCTION

Virtual reality (VR), augmented reality (AR), and mixed reality (MR) are emerging technologies in the field of stroke rehabilitation that have the potential to overcome the limitations of conventional treatment. Enhancing upper limb (UL) function is critical in stroke impairments because the upper limb is involved in the majority of activities of daily living (ADL).

METHODS

This study reviewed the use of virtual, augmented and mixed reality (VAMR) methods for improving UL recovery and ADL, and compared the effectiveness of VAMR treatment to conventional rehabilitation therapy. The databases ScienceDirect, PubMed, IEEE Xplore, and Web of Science were examined, and 50 randomized control trials comparing VAMR treatment to standard therapy were determined. The random effect model and fixed effect model are applied based on heterogeneity.

RESULTS

The most often used outcomes of UL recovery and ADL in stroke rehabilitation were the Fugl-Meyer Assessment for Upper Extremities (FMA-UE), followed by the Box and Block Test (BBT), the Wolf Motor Function Test (WMFT), and the Functional Independence Measure (FIM). According to the meta-analysis, VR, AR, and MR all have a significant positive effect on improving FMA-UE for UL impairment (36 studies, MD = 3.91, 95 percent CI = 1.70-6.12, P = 0.0005) and FIM for ADL (10 studies, MD = 4.25, 95 percent CI = 1.47-7.03, P = 0.003), but not on BBT and WMFT for the UL function tests (16 studies, MD = 2.07, 95 percent CI = - 0.58-4.72, P = 0.13), CONCLUSIONS: VAMR therapy was superior to conventional treatment in UL impairment and daily function outcomes, but not UL function measures. Future studies might include further high-quality trials examining the effect of VR, AR, and MR on UL function measures, with an emphasis on subgroup meta-analysis by stroke type and recovery stage.

Regional cerebral blood perfusion changes in chronic stroke survivors as potential brain correlates of the functional outcome following gamified home-based rehabilitation (IntelliRehab)-a pilot study

BACKGROUND

Hospital-based stroke rehabilitation for stroke survivors in developing countries may be limited by staffing ratios and length of stay that could hamper recovery potential. Thus, a home-based, gamified rehabilitation system (i.e., IntelliRehab) was tested for its ability to increase cerebral blood flow (CBF), and the secondary impact of changes on the upper limb motor function and functional outcomes.

OBJECTIVE

To explore the effect of IntelliRehab on CBF in chronic stroke patients and its correlation with the upper limb motor function.

METHODS

Two-dimensional pulsed Arterial Spin Labelling (2D-pASL) was used to obtain CBF images of stable, chronic stroke subjects (n = 8) over 3-months intervention period. CBF alterations were mapped, and the detected differences were marked as regions of interest. Motor functions represented by Fugl-Meyer Upper Extremity Assessment (FMA) and Stroke Impact Scale (SIS) were used to assess the primary and secondary outcomes, respectively.

RESULTS

Regional CBF were significantly increased in right inferior temporal gyrus and left superior temporal white matter after 1-month (p = 0.044) and 3-months (p = 0.01) of rehabilitation, respectively. However, regional CBF in left middle fronto-orbital gyrus significantly declined after 1-month of rehabilitation (p = 0.012). Moreover, SIS-Q7 and FMA scores significantly increased after 1-month and 3-months of rehabilitation. There were no significant correlations, however, between CBF changes and upper limb motor function.

CONCLUSIONS

Participants demonstrated improved motor functions, supporting the benefit of using IntelliRehab as a tool for home-based rehabilitation. However, within-participant improvements may have limited potential that suggests the need for a timely administration of IntelliRehab to get the maximum capacity of improvement.

Bringing rehabilitation home with an e-health platform to treat stroke patients: study protocol of a randomized clinical trial (RGS@home)

Background

There is a pressing need for scalable healthcare solutions and a shift in the rehabilitation paradigm from hospitals to homes to tackle the increase in stroke incidence while reducing the practical and economic burden for patients, hospitals, and society. Digital health technologies can contribute to addressing this challenge; however, little is known about their effectiveness in at-home settings. In response, we have designed the RGS@home study to investigate the effectiveness, acceptance, and cost of a deep tech solution called the Rehabilitation Gaming System (RGS). RGS is a cloud-based system for delivering AI-enhanced rehabilitation using virtual reality, motion capture, and wearables that can be used in the hospital and at home. The core principles of the brain theory-based RGS intervention are to deliver rehabilitation exercises in the form of embodied, goal-oriented, and task-specific action.

Methods

The RGS@home study is a randomized longitudinal clinical trial designed to assess whether the combination of the RGS intervention with standard care is superior to standard care alone for the functional recovery of stroke patients at the hospital and at home. The study is conducted in collaboration with hospitals in Spain, Sweden, and France and includes inpatients and outpatients at subacute and chronic stages post-stroke. The intervention duration is 3 months with assessment at baseline and after 3, 6, and 12 months. The impact of RGS is evaluated in terms of quality of life measurements, usability, and acceptance using standardized clinical scales, together with health economic analysis. So far, one-third of the patients expected to participate in the study have been recruited (N = 90, mean age 60, days after stroke ≥ 30 days). The trial will end in July 2023.

Discussion

We predict an improvement in the patients’ recovery, high acceptance, and reduced costs due to a soft landing from the clinic to home rehabilitation. In addition, the data provided will allow us to assess whether the prescription of therapy at home can counteract deterioration and improve quality of life while also identifying new standards for online and remote assessment, diagnostics, and intervention across European hospitals.

Trial registration

ClinicalTrials.gov NCT04620707. Registered on November 3, 2020

Effects of virtual reality-based motor control training on inflammation, oxidative stress, neuroplasticity and upper limb motor function in patients with chronic stroke: a randomized controlled trial

BACKGROUND

Immersive virtual reality (VR)-based motor control training (VRT) is an innovative approach to improve motor function in patients with stroke. Currently, outcome measures for immersive VRT mainly focus on motor function. However, serum biomarkers help detect precise and subtle physiological changes. Therefore, this study aimed to identify the effects of immersive VRT on inflammation, oxidative stress, neuroplasticity and upper limb motor function in stroke patients.

METHODS

Thirty patients with chronic stroke were randomized to the VRT or conventional occupational therapy (COT) groups. Serum biomarkers including interleukin 6 (IL-6), intracellular adhesion molecule 1 (ICAM-1), heme oxygenase 1 (HO-1), 8-hydroxy-2-deoxyguanosine (8-OHdG), and brain-derived neurotrophic factor (BDNF) were assessed to reflect inflammation, oxidative stress and neuroplasticity. Clinical assessments including active range of motion of the upper limb and the Fugl-Meyer Assessment for upper extremity (FMA-UE) were also used. Two-way mixed analyses of variance (ANOVAs) were used to examine the effects of the intervention (VRT and COT) and time on serum biomarkers and upper limb motor function.

RESULTS

We found significant time effects in serum IL-6 (p = 0.010), HO-1 (p = 0.002), 8-OHdG (p = 0.045), and all items/subscales of the clinical assessments (ps < 0.05), except FMA-UE-Coordination/Speed (p = 0.055). However, significant group effects existed only in items of the AROM-Elbow Extension (p = 0.007) and AROM-Forearm Pronation (p = 0.048). Moreover, significant interactions between time and group existed in item/subscales of FMA-UE-Shoulder/Elbow/Forearm (p = 0.004), FMA-UE-Total score (p = 0.008), and AROM-Shoulder Flexion (p = 0.001).

CONCLUSION

This was the first study to combine the effectiveness of immersive VRT using serum biomarkers as outcome measures. Our study demonstrated promising results that support the further application of commercial and immersive VR technologies in patients with chronic stroke.

Excitatory-Inhibitory Homeostasis and Diaschisis: Tying the Local and Global Scales in the Post-stroke Cortex

Maintaining a balance between excitatory and inhibitory activity is an essential feature of neural networks of the neocortex. In the face of perturbations in the levels of excitation to cortical neurons, synapses adjust to maintain excitatory-inhibitory (EI) balance. In this review, we summarize research on this EI homeostasis in the neocortex, using stroke as our case study, and in particular the loss of excitation to distant cortical regions after focal lesions. Widespread changes following a localized lesion, a phenomenon known as diaschisis, are not only related to excitability, but also observed with respect to functional connectivity. Here, we highlight the main findings regarding the evolution of excitability and functional cortical networks during the process of post-stroke recovery, and how both are related to functional recovery. We show that cortical reorganization at a global scale can be explained from the perspective of EI homeostasis. Indeed, recovery of functional networks is paralleled by increases in excitability across the cortex. These adaptive changes likely result from plasticity mechanisms such as synaptic scaling and are linked to EI homeostasis, providing a possible target for future therapeutic strategies in the process of rehabilitation. In addition, we address the difficulty of simultaneously studying these multiscale processes by presenting recent advances in large-scale modeling of the human cortex in the contexts of stroke and EI homeostasis, suggesting computational modeling as a powerful tool to tie the meso- and macro-scale processes of recovery in stroke patients.

Effects of Virtual Reality-Based Intervention on Cognition, Motor Function, Mood, and Activities of Daily Living in Patients With Chronic Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: The efficacy of virtual reality (VR)-based intervention for improving cognition in patients with the chronic stage of stroke is controversial. The aims of this meta-analysis were to evaluate the effect of VR-based training combined with traditional rehabilitation on cognition, motor function, mood, and activities of daily living (ADL) after chronic stroke. Methods: The search was performed in the Cochrane Library (CENTRAL), EBSCO, EMBASE, Medline (OVID), Web of Science databases, PubMed, CINAHL Ovid, and Scopus from inception to May 31, 2021. All included studies were randomized controlled trials (RCTs) examining VR-based intervention combined with traditional rehabilitation for chronic stroke. The main outcomes of this study were cognition, including overall cognition (combined with all cognitive measurement results), global cognition (measured by the Montreal Cognitive Assessment, MoCA, and/or Mini-Mental State Examination, MMSE), and attention/execution. The additional outcomes were motor function, mood, and ADL. Subgroup analyses were conducted to verify the potential factors for heterogeneity. Results: Six RCTs including 209 participants were included for systematic review, and five studies of 177 participants were included in meta-analyses. Main outcome analyses showed large and significant effect size (ES) of VR-based training on overall cognition (g = 0.642; 95% CI = 0.134-1.149; and P = 0.013) and attention/execution (g = 0.695; 95% CI = 0.052-1.339; and P = 0.034). Non-significant result was found for VR-based intervention on global cognition (g = 0.553; 95% CI = -0.273-1.379; and P = 0.189). Additional outcome analyses showed no superiority of VR-based intervention over traditional rehabilitation on motor function and ADL. The ES of VR-based intervention on mood (g = 1.421; 95% CI = 0.448-2.393; and P = 0.004) was large and significant. In the subgroup analysis, large effects for higher daily intensity, higher weekly frequency, or greater dose of VR intervention were found. Conclusion: Our findings indicate that VR-based intervention combined with traditional rehabilitation showed better outcomes for overall cognition, attention/execution, and depressive mood in individuals with chronic stroke. However, VR-based training combined with traditional rehabilitation showed a non-significant effect for global cognition, motor function, and ADL in individuals with chronic stroke.

Effectiveness of a combined transcranial direct current stimulation and virtual reality-based intervention on upper limb function in chronic individuals post-stroke with persistent severe hemiparesis: a randomized controlled trial

BACKGROUND

Functional impairments derived from the non-use of severely affected upper limb after stroke have been proposed to be mitigated by action observation and imagination-based techniques, whose effectiveness is enhanced when combined with transcranial direct current stimulation (tDCS). Preliminary studies in mildly impaired individuals in the acute phase post-stroke show intensified effects when action is facilitated by tDCS and mediated by virtual reality (VR) but the effectiveness in cases of severe impairment and chronic stroke is unknown. This study investigated the effectiveness of a combined tDCS and VR-based intervention in the sensorimotor function of chronic individuals post-stroke with persistent severe hemiparesis compared to conventional physical therapy.

METHODS

Twenty-nine participants were randomized into an experimental group, who received 30 minutes of the combined tDCS and VR-based therapy and 30 minutes of conventional physical therapy, or a control group, who exclusively received conventional physical therapy focusing on passive and active assistive range of motion exercises. The sensorimotor function of all participants was assessed before and after 25 one-hour sessions, administered three to five times a week, using the upper extremity subscale of the Fugl-Meyer Assessment, the time and ability subscales of the Wolf Motor Function Test, and the Nottingham Sensory Assessment.

RESULTS

A clinically meaningful improvement of the upper limb motor function was consistently revealed in all motor measures after the experimental intervention, but not after conventional physical therapy. Similar limited effects were detected in the sensory function in both groups.

CONCLUSION

The combined tDCS and VR-based paradigm provided not only greater but also clinically meaningful improvement in the motor function (and similar sensory effects) in comparison to conventional physical therapy.

The effect of video game-based training on postural control during gait initiation in community-dwelling older adults: a randomized controlled trial

PURPOSE

The aim was to investigate the effect of video game training as compared to dual-task training on gait initiation (GI) which is a sensitive indicator of balance deficiency in older adults.

METHOD

Sixty-six older adults were allocated to the video game-based training (intervention group) or the motor-cognitive dual-task training (active control group). The outcome measures were the mediolateral (ML)/anteroposterior (AP) displacement and velocity of COP during the phases of GI (anticipatory, weight transition, and locomotor).

RESULTS

The results indicated in the anticipatory phase, the ML & AP COP displacement were significantly increased at post-training relative to pre-training across both groups (p < 0.041). In the weight transition phase, the AP COP displacement & ML COP velocity were significantly increased at post-training than pre-training (p < 0.032). However, in the locomotor phase, within the intervention group, the ML COP displacement & ML COP velocity were significantly increased at follow-up as compared to pre-training (p < 0.05), while no such differences were observed within the control group.

CONCLUSION

Both treatments were effective in improving COP trajectory during the phases of anticipatory and weight transition, while the intervention group was more effective during the phase of locomotor. So, these treatments can be recommended for clinical settings.Implications for rehabilitationThe video game and dual task training were effective in improving COP trajectory during the phases of anticipatory and weight transition.The video game-based training was more effective during the phase of locomotor.The study findings could have useful implications to further introduce cognition-based rehabilitation programs such as video games for older adults.Rehabilitation professionals could use the video game to improve the postural control of older adults.

Effect of a Brain-Computer Interface Based on Pedaling Motor Imagery on Cortical Excitability and Connectivity

Recently, studies on cycling-based brain–computer interfaces (BCIs) have been standing out due to their potential for lower-limb recovery. In this scenario, the behaviors of the sensory motor rhythms and the brain connectivity present themselves as sources of information that can contribute to interpreting the cortical effect of these technologies. This study aims to analyze how sensory motor rhythms and cortical connectivity behave when volunteers command reactive motor imagery (MI) BCI that provides passive pedaling feedback. We studied 8 healthy subjects who performed pedaling MI to command an electroencephalography (EEG)-based BCI with a motorized pedal to receive passive movements as feedback. The EEG data were analyzed under the following four conditions: resting, MI calibration, MI online, and receiving passive pedaling (on-line phase). Most subjects produced, over the foot area, significant event-related desynchronization (ERD) patterns around Cz when performing MI and receiving passive pedaling. The sharpest decrease was found for the low beta band. The connectivity results revealed an exchange of information between the supplementary motor area (SMA) and parietal regions during MI and passive pedaling. Our findings point to the primary motor cortex activation for most participants and the connectivity between SMA and parietal regions during pedaling MI and passive pedaling.

A novel fully immersive virtual reality environment for upper extremity rehabilitation in patients with stroke

Given the rising incidence of stroke, several technology-driven methods for rehabilitation have recently been developed. Virtual reality (VR) is a promising therapeutic technology among them. We recently developed a neuroscientifically grounded VR system to aid recovery of motor function poststroke. The developed system provides unilateral and bilateral upper extremity (UE) training in a fully immersive virtual environment that may stimulate and activate mirror neurons (MNs) in the brain necessary for UE rehabilitation. Twenty-three participants were randomized to a VR group (n = 12) to receive VR intervention (8 h within 2 weeks) plus 8-h occupational therapy (OT) or a control group (n = 11) to receive time-matched OT alone. Treatment effects on motor recovery and cortical reorganization were investigated using the Barthel Index (BI), Fugl-Meyer Upper Extremity (FM-UE), and resting-state fMRI. Both groups significantly improved BI (P < 0.05), reflecting the recovery of UE motor function. The VR group revealed significant improvements on FM-UE scores (P < 0.05) than the control group. Neural activity increased after the intervention, particularly in the brain areas implicating MNs, such as in the primary motor cortex. Overall, results suggested that using a neuroscientifically grounded VR system might offer additional benefits for UE rehabilitation in patients receiving OT.

Neurophysiological Correlates of Cognition as Revealed by Virtual Reality: Delving the Brain with a Synergistic Approach

The synergy of perceptual psychology, technology, and neuroscience can be used to comprehend how virtual reality affects cognition of human brain. Numerous studies have used neuroimaging modalities to assess the cognitive state and response of the brain with various external stimulations. The virtual reality-based devices are well known to incur visual, auditory, and haptic induced perceptions. Neurophysiological recordings together with virtual stimulations can assist in correlating humans’ physiological perception with response in the environment designed virtually. The effective combination of these two has been utilized to study human behavior, spatial navigation performance, and spatial presence, to name a few. Moreover, virtual reality-based devices can be evaluated for the neurophysiological correlates of cognition through neurophysiological recordings. Challenges exist in the integration of real-time neuronal signals with virtual reality-based devices, and enhancing the experience together with real-time feedback and control through neuronal signals. This article provides an overview of neurophysiological correlates of cognition as revealed by virtual reality experience, together with a description of perception and virtual reality-based neuromodulation, various applications, and existing challenges in this field of research.

Proactive Motor Functional Recovery Following Immersive Virtual Reality-Based Limb Mirroring Therapy in Patients with Subacute Stroke

Virtual reality (VR) is considered to be a promising therapeutic technology for the rehabilitation of upper extremities (UEs) post-stroke. Recently, we designed and then implemented a neuroscientifically grounded VR protocol for the rehabilitation of patients with stroke. The system provides unilateral and bilateral limb mirroring exercises in a fully immersive virtual environment that may stimulate and activate the mirror neuron system in the brain to help patients for their rehabilitation. Twelve patients with subacute stroke underwent the newly implemented VR treatment in addition to conventional rehabilitation for 8 consecutive weekdays. The treatment effect on brain reorganization and motor function was investigated using resting-state fMRI (rs-fMRI) and the Fugl-Meyer assessment for Upper Extremity (FM-UE), respectively. Fifteen healthy controls (HCs) also underwent rs-fMRI scanning one time. The study finally obtained usable data from 8 patients and 13 HCs. After the intervention, patients demonstrated significant improvement in their FM-UE scores (p values < 0.042). Voxel-wise functional connectivity (FC) analysis based on the rs-fMRI data found that HCs showed widespread bilateral FC patterns associated with the dominant hemispheric primary motor cortex (M1). However, the FC patterns in patients revealed intra-hemispheric association with the ipsilesional M1 seed and this association became visible in the contra-hemisphere after the intervention. Moreover, the change of FC values between the bilateral M1 was significantly correlated with the changes in FM-UE scores (p values < 0.037). We conclude that unilateral and bilateral limb mirroring exercise in an immersive virtual environment may enhance cortical reorganization and lead to improved motor function.

How brain imaging provides predictive biomarkers for therapeutic success in the context of virtual reality cognitive training

As Virtual reality (VR) is increasingly used in neurological disorders such as stroke, traumatic brain injury, or attention deficit disorder, the question of how it impacts the brain's neuronal activity and function becomes essential. VR can be combined with neuroimaging to offer invaluable insight into how the targeted brain areas respond to stimulation during neurorehabilitation training. That, in turn, could eventually serve as a predictive marker for therapeutic success. Functional magnetic resonance imaging (fMRI) identified neuronal activity related to blood flow to reveal with a high spatial resolution how activation patterns change, and restructuring occurs after VR training. Portable and quiet, electroencephalography (EEG) conveniently allows the clinician to track spontaneous electrical brain activity in high temporal resolution. Then, functional near-infrared spectroscopy (fNIRS) combines the spatial precision level of fMRIs with the portability and high temporal resolution of EEG to constitute an ideal measuring tool in virtual environments (VEs). This narrative review explores the role of VR and concurrent neuroimaging in cognitive rehabilitation.

The medical avatar and its role in neurorehabilitation and neuroplasticity: A review

BACKGROUND

One of the most interesting emerging medical devices is the medical avatar - a digital representation of the patient that can be used toward myriad ends, the full potential of which remains to be explored. Medical avatars have been instantiated as telemedical tools used to establish a representation of the patient in tele-space, upon which data about the patient's health can be represented and goals and progress can be visually tracked. Manipulation of the medical avatar has also been explored as a means of increasing motivation and inducing neural plasticity.

OBJECTIVE

The article reviews the literature on body representation, simulation, and action-observation and explores how these components of neurorehabilitation are engaged by an avatar-based self-representation.

METHODS

Through a review of the literature on body representation, simulation, and action-observation and a review of how these components of neurorehabilitation can be engaged and manipulated with an avatar, the neuroplastic potential of the medical avatar is explored. Literature on the use of the medical avatar for neurorehabilitation is also reviewed.

RESULTS

This review demonstrates that the medical avatar has vast potentialities in neurorehabilitation and that further research on its use and effect is needed.

Video game-based therapy for the non-dominant hand improves manual skills and grip strength

The study was designed to investigate the effect of virtual reality-supported training on manual skills and grip strength in the non-dominant hand in healthy participants. Thirty participants were randomized into two groups: ErgoActive group (n=15) and control group (n=15). The ErgoActive study group received 8 weeks of training with leap motion controller-based virtual reality games. The training was done 1 day per week for 30min. The participants' hand function was evaluated using the Jebsen Taylor Hand Function Test (JTHFT), while grip strength was evaluated with a Jamar Hand Dynamometer and Pinchmeter. After 8 weeks, the ErgoActive and control groups had significantly different JTHFT, Jamar and Pinchmeter results (P<0.05). When leap motion controller-based virtual reality applications are used, healthy subjects have increased manual skills and grip strength in their non-dominant hand. These virtual reality games are an effective and fun way of improving patients' hand functions.

Adaptive conjunctive cognitive training (ACCT) in virtual reality for chronic stroke patients: a randomized controlled pilot trial

BACKGROUND

Current evidence for the effectiveness of post-stroke cognitive rehabilitation is weak, possibly due to two reasons. First, patients typically express cognitive deficits in several domains. Therapies focusing on specific cognitive deficits might not address their interrelated neurological nature. Second, co-occurring psychological problems are often neglected or not diagnosed, although post-stroke depression is common and related to cognitive deficits. This pilot trial aims to test a rehabilitation program in virtual reality that trains various cognitive domains in conjunction, by adapting to the patient's disability and while investigating the influence of comorbidities.

METHODS

Thirty community-dwelling stroke patients at the chronic stage and suffering from cognitive impairment performed 30 min of daily training for 6 weeks. The experimental group followed, so called, adaptive conjunctive cognitive training (ACCT) using RGS, whereas the control group solved standard cognitive tasks at home for an equivalent amount of time. A comprehensive test battery covering executive function, spatial awareness, attention, and memory as well as independence, depression, and motor impairment was applied at baseline, at 6 weeks and 18-weeks follow-up.

RESULTS

At baseline, 75% of our sample had an impairment in more than one cognitive domain. The experimental group showed improvements in attention ([Formula: see text] (2) = 9.57, p < .01), spatial awareness ([Formula: see text] (2) = 11.23, p < .01) and generalized cognitive functioning ([Formula: see text] (2) = 15.5, p < .001). No significant change was seen in the executive function and memory domain. For the control group, no significant change over time was found. Further, they worsened in their depression level after treatment (T = 45, r = .72, p < .01) but returned to baseline at follow-up. The experimental group displayed a lower level of depression than the control group after treatment (Ws = 81.5, z = - 2.76, r = - .60, p < .01) and (Ws = 92, z = - 2.03, r = - .44, p < .05).

CONCLUSIONS

ACCT positively influences attention and spatial awareness, as well as depressive mood in chronic stroke patients.

TRIAL REGISTRATION

The trial was registered prospectively at ClinicalTrials.gov (NCT02816008) on June 21, 2016.

The Potential of Virtual Reality for Inducing Neuroplasticity in Children with Amblyopia

In recent years, virtual reality (VR) has emerged as a new safe and effective tool for neurorehabilitation of different childhood and adulthood conditions. VR-based therapies can induce cortical reorganization and promote the activation of different neuronal connections over a wide range of ages, leading to contrasted improvements in motor and functional skills. The use of VR for the visual rehabilitation in amblyopia has been investigated in the last years, with the potential of using serious games combining perceptual learning and dichoptic stimulation. This combination of technologies allows the clinician to measure, treat, and control changes in interocular suppression, which is one of the factors leading to cortical alterations in amblyopia. Several clinical researches on this issue have been conducted, showing the potential of promoting visual acuity, contrast sensitivity, and stereopsis improvement. Indeed, several systems have been evaluated for amblyopia treatment including the use of different commercially available types of head mounted displays (HMDs). These HMDs are mostly well tolerated by patients during short exposures and do not cause significant long-term side effects, although their use has been occasionally associated with some visual discomfort and other complications in certain types of subjects. More studies are needed to confirm these promising therapies in controlled randomized clinical trials, with special emphasis on the definition of the most adequate planning for obtaining an effective recovery of the visual and binocular function.

Is it necessary to show virtual limbs in action observation neurorehabilitation systems?

Introduction

Action observation neurorehabilitation systems are usually based on the observation of a virtual limb performing different kinds of actions. In this way, the activity in the frontoparietal Mirror Neuron System is enhanced, which can be helpful to rehabilitate stroke patients. However, the presence of limbs in such systems might not be necessary to produce mirror activity, for example, frontoparietal mirror activity can be produced just by the observation of virtual tool movements. The objective of this work was to explore to what point the presence of a virtual limb impacts the Mirror Neuron System activity in neurorehabilitation systems.

Methods

The study was conducted by using an action observation neurorehabilitation task during a functional magnetic resonance imaging (fMRI) experiment with healthy volunteers and comparing two action observation conditions that: 1 – included or 2 – did not include a virtual limb.

Results

It was found that activity in the Mirror Neuron System was similar during both conditions (i.e. virtual limb present or absent).

Conclusions

These results open up the possibility of using new tasks that do not include virtual limbs in action observation neurorehabilitation environments, which can give more freedom to develop such systems.

Effects of virtual reality therapy on upper limb function after stroke and the role of neuroimaging as a predictor of a better response

OBJECTIVE

Virtual reality therapy (VRT) is an interactive intervention that induces neuroplasticity. The aim was to evaluate the effects of VRT associated with conventional rehabilitation for an upper limb after stroke, and the neuroimaging predictors of a better response to VRT.

METHODS

Patients with stroke were selected, and clinical neurological, upper limb function, and quality of life were evaluated. Statistical analysis was performed using a linear model comparing pre- and post-VRT. Lesions were segmented in the post-stroke computed tomography. A voxel-based lesion-symptom mapping approach was used to investigate the relationship between the lesion and upper limb function.

RESULTS

Eighteen patients were studied (55.5 ± 13.9 years of age). Quality of life, functional independence, and dexterity of the upper limb showed improvement after VRT (p < 0.001). Neuroimaging analysis showed negative correlations between the internal capsule lesion and functional recovery.

CONCLUSION

VRT showed benefits for patients with stroke, but when there was an internal capsule lesion, a worse response was observed.

Virtual reality experiences, embodiment, videogames and their dimensions in neurorehabilitation

Background

In the context of stroke rehabilitation, new training approaches mediated by virtual reality and videogames are usually discussed and evaluated together in reviews and meta-analyses. This represents a serious confounding factor that is leading to misleading, inconclusive outcomes in the interest of validating these new solutions.

Main body

Extending existing definitions of virtual reality, in this paper I put forward the concept of virtual reality experience (VRE), generated by virtual reality systems (VRS; i.e. a group of variable technologies employed to create a VRE). Then, I review the main components composing a VRE, and how they may purposely affect the mind and body of participants in the context of neurorehabilitation. In turn, VRS are not anymore exclusive from VREs but are currently used in videogames and other human-computer interaction applications in different domains. Often, these other applications receive the name of virtual reality applications as they use VRS. However, they do not necessarily create a VRE. I put emphasis on exposing fundamental similarities and differences between VREs and videogames for neurorehabilitation. I also recommend describing and evaluating the specific features encompassing the intervention rather than evaluating virtual reality or videogames as a whole.

Conclusion

This disambiguation between VREs, VRS and videogames should help reduce confusion in the field. This is important for databases searches when looking for specific studies or building metareviews that aim at evaluating the efficacy of technology-mediated interventions.

Conjunctive rehabilitation of multiple cognitive domains for chronic stroke patients in virtual reality

Classically, cognitive deficits have been studied and treated in isolation from each other. A stroke patient is classified as being memory impaired, having executive dysfunction or showing attentional deficits after which a dedicated rehabilitation therapy is given. Studies seldom looked at the relationship between these different cognitive domains and syndromes, although, there is evidence that they might share common neuronal substrates and do not occur in isolation. Here, we propose a novel rehabilitation method in virtual reality to treat cognitive deficits in conjunction and report the preliminary results of an ongoing randomized controlled clinical trial. The current results suggest that in a homogeneous patient group the cognitive deficits are correlated and that the individual impairment level can be optimally addressed through an adaptive training paradigm.

Cerebral Reorganization in Subacute Stroke Survivors after Virtual Reality-Based Training: A Preliminary Study

Background

Functional magnetic resonance imaging (fMRI) is a promising method for quantifying brain recovery and investigating the intervention-induced changes in corticomotor excitability after stroke. This study aimed to evaluate cortical reorganization subsequent to virtual reality-enhanced treadmill (VRET) training in subacute stroke survivors.

Methods

Eight participants with ischemic stroke underwent VRET for 5 sections per week and for 3 weeks. fMRI was conducted to quantify the activity of selected brain regions when the subject performed ankle dorsiflexion. Gait speed and clinical scales were also measured before and after intervention.

Results

Increased activation in the primary sensorimotor cortex of the lesioned hemisphere and supplementary motor areas of both sides for the paretic foot (p < 0.01) was observed postintervention. Statistically significant improvements were observed in gait velocity (p < 0.05). The change in voxel counts in the primary sensorimotor cortex of the lesioned hemisphere is significantly correlated with improvement of 10 m walk time after VRET (r = −0.719).

Conclusions

We observed improved walking and increased activation in cortical regions of stroke survivors after VRET training. Moreover, the cortical recruitment was associated with better walking function. Our study suggests that cortical networks could be a site of plasticity, and their recruitment may be one mechanism of training-induced recovery of gait function in stroke. This trial is registered with ChiCTR-IOC-15006064.

Influence of the actions observed on cervical motion in patients with chronic neck pain: a pilot study

The aim of the present pilot study was to prove if the action-observation (AOb) improved the cervical range of motion (CROM) in patients with nonspecific chronic neck pain (CNP). Double blind pilot study. A total of 28 subjects were randomly assigned to an effective-movement group (n=14) and an ineffective-movement group (n=14). The follow-up consisted of: pretreatment, posttreatment and 10 min after second measurement (motor imagery). Outcome measures were CROM, and pres-sure pain detection thresholds (PPDTs). No statistical differences were found in baseline on CROM and on the PPDT. Test for independent groups revealed significant changes in cervical rotation movement. Both groups in posttreatment (P=0.042; Cohen d=0.81) and after 10 min (P=0.019; Cohen d=0.9). For intragroup PPDT, the Wilcoxon test revealed significant effects in the effective movement at C2 of the pre to 10-min post (P=0.040). However, the ineffective movement revealed a significant reduction in PPDT in zygapophyseal joint of C5-C6 as the pre to post (P=0.010) as the pre to 10-min post (P=0.041) periods. In conclusions this pilot study demonstrated that the effective AOb produced significant changes versus ineffective AOb in the CROM and it could influences in PPT in subject with CNP immediately.

Counteracting learned non-use in chronic stroke patients with reinforcement-induced movement therapy

Background

After stroke, patients who suffer from hemiparesis tend to suppress the use of the affected extremity, a condition called learned non-use. Consequently, the lack of training may lead to the progressive deterioration of motor function. Although Constraint-Induced Movement Therapies (CIMT) have shown to be effective in treating this condition, the method presents several limitations, and the high intensity of its protocols severely compromises its adherence. We propose a novel rehabilitation approach called Reinforcement-Induced Movement Therapy (RIMT), which proposes to restore motor function through maximizing arm use. This is achieved by exposing the patient to amplified goal-oriented movements in VR that match the intended actions of the patient. We hypothesize that through this method we can increase the patients self-efficacy, reverse learned non-use, and induce long-term motor improvements.

Methods

We conducted a randomized, double-blind, longitudinal clinical study with 18 chronic stroke patients. Patients performed 30 minutes of daily VR-based training during six weeks. During training, the experimental group experienced goal-oriented movement amplification in VR. The control group followed the same training protocol but without movement amplification. Evaluators blinded to group designation performed clinical measurements at the beginning, at the end of the training and at 12-weeks follow-up. We used the Fugl-Meyer Assessment for the upper extremities (UE-FM) (Sanford et al., Phys Ther 73:447–454, 1993) as a primary outcome measurement of motor recovery. Secondary outcome measurements included the Chedoke Arm and Hand Activity Inventory (CAHAI-7) (Barreca et al., Arch Phys Med Rehabil 6:1616–1622, 2005) for measuring functional motor gains in the performance of Activities of Daily Living (ADLs), the Barthel Index (BI) for the evaluation of the patient’s perceived independence (Collin et al., Int Disabil Stud 10:61–63, 1988), and the Hamilton scale (Knesevich et al., Br J Psychiatr J Mental Sci 131:49–52, 1977) for the identification of improvements in mood disorders that could be induced by the reinforcement-based intervention. In order to study and predict the effects of this intervention we implemented a computational model of recovery after stroke.

Results

While both groups showed significant motor gains at 6-weeks post-treatment, only the experimental group continued to exhibit further gains in UE-FM at 12-weeks follow-up (p<.05). This improvement was accompanied by a significant increase in arm-use during training in the experimental group.

Conclusions

Implicitly reinforcing arm-use by augmenting visuomotor feedback as proposed by RIMT seems beneficial for inducing significant improvement in chronic stroke patients. By challenging the patients’ self-limiting believe system and perceived low self-efficacy this approach might counteract learned non-use.

Trial registration

Clinical Trials NCT02657070.

Electronic supplementary material

The online version of this article (doi:10.1186/s12984-016-0178-x) contains supplementary material, which is available to authorized users.

Virtual Reality-Guided Motor Imagery Increases Corticomotor Excitability in Healthy Volunteers and Stroke Patients

Objective

To investigate the effects of using motor imagery (MI) in combination with a virtual reality (VR) program on healthy volunteers and stroke patients. In addition, this study investigated whether task variability within the VR-guided MI programs would influence corticomotor excitability.

Methods

The present study included 15 stroke patients and 15 healthy right-handed volunteers who were presented with four different conditions in a random order: rest, MI alone, VR-guided MI, and VR-guided MI with task variability. The corticomotor excitability of each participant was assessed before, during, and after each condition by measuring changes in the various parameters of motor-evoked potentials (MEPs) of the extensor carpi radials (ECR). Changes in intracortical inhibition (ICI) and intracortical facilitation (ICF) were calculated after each condition as percentages of inhibition (%INH) and facilitation (%FAC) at rest.

Results

In both groups, the increases in MEP amplitudes were greater during the two VR-guided MI conditions than during MI alone. Additionally, the reductions in ECR %INH in both groups were greater under the condition involving VR-guided MI with task variability than under that involving VR-guided MI with regular interval.

Conclusion

The corticomotor excitability elicited by MI using a VR avatar representation was greater than that elicited by MI with real body observations. Furthermore, the use of task variability in a VR program may enhance neural regeneration after stroke by reducing ICI. The present findings support the use of various VR programs as well as the concept of combining MI with VR programs for neurorehabilitation.

Virtual reality gaming in the rehabilitation of the upper extremities post-stroke

BACKGROUND

Occurrences of strokes often result in unilateral upper limb dysfunction. Dysfunctions of this nature frequently persist and can present chronic limitations to activities of daily living.

METHODS

Research into applying virtual reality gaming systems to provide rehabilitation therapy have seen resurgence. Themes explored in stroke rehab for paretic limbs are action observation and imitation, versatility, intensity and repetition and preservation of gains. Fifteen articles were ultimately selected for review. The purpose of this literature review is to compare the various virtual reality gaming modalities in the current literature and ascertain their efficacy.

RESULTS

The literature supports the use of virtual reality gaming rehab therapy as equivalent to traditional therapies or as successful augmentation to those therapies. While some degree of rigor was displayed in the literature, small sample sizes, variation in study lengths and therapy durations and unequal controls reduce generalizability and comparability.

CONCLUSIONS

Future studies should incorporate larger sample sizes and post-intervention follow-up measures.

Processing emotional body expressions: state-of-the-art

Processing emotional body expressions has become recently an important topic in affective and social neuroscience along with the investigation of facial expressions. The objective of the study is to review the literature on emotional body expressions in order to discuss the current state of knowledge on this topic and identify directions for future research. The following electronic databases were searched: PsychINFO, Ebsco, ERIC, ProQuest, Sagepub, and SCOPUS using terms such as "body," "bodily expression," "body perception," "emotions," "posture," "body recognition" and combinations of them. The synthesis revealed several research questions that were addressed in neuroimaging, electrophysiological and behavioral studies. Among them, one important question targeted the neural mechanisms of emotional processing of body expressions to specific subsections regarding the time course for the integration of emotional signals from face and body, as well as the role of context in the perception of emotional signals. Processing bodily expression of emotion is similar to processing facial expressions, and the holistic processing is extended to the whole person. The current state-of-the-art in processing emotional body expressions may lead to a better understanding of the underlying neural mechanisms of social behavior. At the end of the review, suggestions for future research directions are presented.

Recovery Potential After Acute Stroke

In acute stroke, the major factor for recovery is the early use of thrombolysis aimed at arterial recanalization and reperfusion of ischemic brain tissue. Subsequently, neurorehabilitative training critically improves clinical recovery due to augmention of postlesional plasticity. Neuroimaging and electrophysiology studies have revealed that the location and volume of the stroke lesion, the affection of nerve fiber tracts, as well as functional and structural changes in the perilesional tissue and in large-scale bihemispheric networks are relevant biomarkers of post-stroke recovery. However, associated disorders, such as mood disorders, epilepsy, and neurodegenerative diseases, may induce secondary cerebral changes or aggravate the functional deficits and, thereby, compromise the potential for recovery.

Utility of a Three-Dimensional Interactive Augmented Reality Program for Balance and Mobility Rehabilitation in the Elderly: A Feasibility Study

Objective

To improve lower extremity function and balance in elderly persons, we developed a novel, three-dimensional interactive augmented reality system (3D ARS). In this feasibility study, we assessed clinical and kinematic improvements, user participation, and the side effects of our system.

Methods

Eighteen participants (age, 56-76 years) capable of walking independently and standing on one leg were recruited. The participants received 3D ARS training during 10 sessions (30-minute duration each) for 4 weeks. Berg Balance Scale (BBS) and the Timed Up and Go (TUG) scores were obtained before and after the exercises. Outcome performance variables, including response time and success rate, and kinematic variables, such as hip and knee joint angle, were evaluated after each session.

Results

Participants exhibited significant clinical improvements in lower extremity balance and mobility following the intervention, as shown by improved BBS and TUG scores (p<0.001). Consistent kinematic improvements in the maximum joint angles of the hip and knee were observed across sessions. Outcome performance variables, such as success rate and response time, improved gradually across sessions, for each exercise. The level of participant interest also increased across sessions (p<0.001). All participants completed the program without experiencing any adverse effects.

Conclusion

Substantial clinical and kinematic improvements were observed after applying a novel 3D ARS training program, suggesting that this system can enhance lower extremity function and facilitate assessments of lower extremity kinematic capacity.

The visual amplification of goal-oriented movements counteracts acquired non-use in hemiparetic stroke patients

BACKGROUND

Stroke-induced impairments result from both primary and secondary causes, i.e. damage to the brain and the acquired non-use of the impaired limbs. Indeed, stroke patients often under-utilize their paretic limb despite sufficient residual motor function. We hypothesize that acquired non-use can be overcome by reinforcement-based training strategies.

METHODS

Hemiparetic stroke patients (n = 20, 11 males, 9 right-sided hemiparesis) were asked to reach targets appearing in either the real world or in a virtual environment. Sessions were divided into 3 phases: baseline, intervention and washout. During the intervention the movement of the virtual representation of the patients' paretic limb was amplified towards the target.

RESULTS

We found that the probability of using the paretic limb during washout was significantly higher in comparison to baseline. Patients showed generalization of these results by displaying a more substantial workspace in real world task. These gains correlated with changes in effector selection patterns.

CONCLUSIONS

The amplification of the movement of the paretic limb in a virtual environment promotes the use of the paretic limb in stroke patients. Our findings indicate that reinforcement-based therapies may be an effective approach for counteracting learned non-use and may modulate motor performance in the real world.

Virtual reality interface devices in the reorganization of neural networks in the brain of patients with neurological diseases

Two key characteristics of all virtual reality applications are interaction and immersion. Systemic interaction is achieved through a variety of multisensory channels (hearing, sight, touch, and smell), permitting the user to interact with the virtual world in real time. Immersion is the degree to which a person can feel wrapped in the virtual world through a defined interface. Virtual reality interface devices such as the Nintendo® Wii and its peripheral nunchuks-balance board, head mounted displays and joystick allow interaction and immersion in unreal environments created from computer software. Virtual environments are highly interactive, generating great activation of visual, vestibular and proprioceptive systems during the execution of a video game. In addition, they are entertaining and safe for the user. Recently, incorporating therapeutic purposes in virtual reality interface devices has allowed them to be used for the rehabilitation of neurological patients, e.g., balance training in older adults and dynamic stability in healthy participants. The improvements observed in neurological diseases (chronic stroke and cerebral palsy) have been shown by changes in the reorganization of neural networks in patients' brain, along with better hand function and other skills, contributing to their quality of life. The data generated by such studies could substantially contribute to physical rehabilitation strategies.