Posts Tagged motor imagery

[ARTICLE] The Effects of Combined Low Frequency Repetitive Transcranial Magnetic Stimulation and Motor Imagery on Upper Extremity Motor Recovery Following Stroke – Full Text

Objective: To investigate the effects of low frequency transcranial magnetic stimulation (LF-rTMS) combined with motor imagery (MI) on upper limb motor function during stroke rehabilitation.

Background: Hemiplegic upper extremity activity obstacle is a common movement disorder after stroke. Compared with a single intervention, sequential protocol or combination of several techniques has been proven to be better for alleviating motor function disorder. Non-invasive neuromodulation techniques such as repetitive transcranial magnetic stimulation (rTMS) and motor imagery (MI) have been verified to augment the efficacy of rehabilitation.

Methods:Participants were randomly assigned to 2 intervention cohorts: (1) experimental group (rTMS+MI group) was applied at 1 Hz rTMS over the primary motor cortex of the contralesional hemisphere combined with audio-based MI; (2) control group (rTMS group) received the same therapeutic parameters of rTMS combined with audiotape-led relaxation. LF-rTMS protocol was conducted in 10 sessions over 2 weeks for 30 min. Functional measurements include Wolf Motor Function Test (WMFT), the Fugl-Meyer Assessment Upper Extremity (UE-FMA) subscore, the Box and Block Test (BBT), and the Modified Barthel index (MBI) were conducted at baseline, the second week (week 2) and the fourth week (week 4).

Results: All assessments of upper limb function improved in both groups at weeks 2 and 4. In particular, significant differences were observed between two groups at end-intervention and after intervention (p < 0.05). In these findings, we saw greater changes of WMFT (p < 0.01), UE-FMA (p < 0.01), BBT (p < 0.01), and MBI (p < 0.001) scores in the experimental group.

Conclusions: LF-rTMS combined with MI had a positive effect on motor function of upper limb and can be used for the rehabilitation of upper extremity motor recovery in stroke patients.


Decreased mobility of hemiplegic upper limb is a common dyskinesia after stroke. At present, clinical researchers have established a number of treatments to improve upper extremity motor function (1). Compared with a single intervention, a combination approach of different techniques has been proven to be better for alleviating movement disorder (2). Lots of trials have shown that movement function improvement after stroke can be enhanced by non-invasive brain stimulation techniques combined with conventional clinical practice (36).

Repetitive transcranial magnetic stimulation (rTMS) is one of non-invasive brain stimulations, and could modulate cortical activity. Stroke is considered to be one possible reason for imbalance of interhemispheric cortical inhibition. rTMS could rebulid the interhemisphere balance by down-regulating the excitability of the non-lesioned hemisphere with low frequency stimulation or up-regulating the lesioned excitability by high frequency stimulation (6). Randomized controlled trials have shown that short courses of inhibitory, contralesional rTMS can improve the motor function of hemiplegia after stroke (78). Evidence suggested that maximum control of the lesioned hemisphere is associated with better function (910). Early damage affected the ability of upper motor neurons to compete with lateral neurons to dominate motor neurons (11). Inhibition of contralateral primary motor cortex (M1) with 1 Hz rTMS may enhance hemispheric motor function. This method has revealed efficacy in the stroke rehabilitation for adults although they do not share the same models (8). Recently, the positive effects of HF-rTMS and LF-rTMS on movement disorder after stroke have been supported by accumulating evidence (7). And LF-rTMS has been confirmed to be in correlation with improved function in patients with chronic stroke (1213). Nowadays, a meta-analysis by Zhang et al. evaluated the therapeutic potential of LF-rTMS on stroke-induced upper limb movement disorder and cortex plasticity. This research supported that, as an add-on therapy, LF-rTMS successfully alleviated the hemiplegic upper limb motor deficit and significantly promoted upper limb function improvement after stroke (14).

Another non-invasive neuromodulation technique-motor imagery (MI), has been validated to increase the efficacy of rehabilitation and improve the performance of tasks associated with MI in patients after stroke (1517). The functional recovery of most stroke patients occurred mainly in the first 3 months, and the functional gain obtained in the chronic phase was limited (18). A possible cause of limited functional recovery in the chronic phase is learned nouse. Patients with severe impairment cannot use their paretic limbs in daily activities may be the reason (19). MI is a dynamic state during which the subject mentally simulates a specific movement without any obvious movement (20). It means that MI has no strict restrictions on the patient’s upper limb motor function, so it can be applied to stroke patients with poor function in chronic phase. According to previous studies, MI and motor execution share the same neural networks related to motor function (172122). These findings support the idea that MI can be used as a substitute for physical exercise which is difficult for patients to do (23). MI training was assumed to enhance motor recovery in stroke rehabilitation (24). Based on traditional rehabilitation training, MI training is more effective than conventional training alone (17). For example, Kang et al. and Xu et al. demonstrated an increase in neural activity in the motor area during MI training (2526). And Kawakami et al. also investigated changes of cortex in reciprocal inhibition following MI in patients with chronic stroke, and reported positive plastic changes during mental practice with MI (27). In another pilot study, Mihara et al. demonstrated that NIRS-mediated neurofeedback MI could enhance the ipsilesional premotor area activation in correlation with MI training and could have significant effects on the motor deficit recovery in stroke patients. Besides these findings, they also found that the change of cortical activation was related to the recovery of the hand function (19).

In view of the fact that rTMS and MI have no strict restrictions on the limb function of patients with chronic stroke, this study intends to combine the two interventions to maximize the motor function recovery of patients. As the author know, few studies explore whether the effect of LF-rTMS can be enhanced by combining with MI on upper extremity activity. In this study, we hypothesize that combination therapy of LF-rTMS with MI training will promote recovery from upper limb movement disorder in patients after chronic stroke; we also predict that activities of daily living might improve accordingly.

Therefore, the objective was to investigate the effects of LF-rTMS combined with MI on improving motor functions of hemiplegic upper extremity in chronic stroke patients.[…]


Continue —>  Frontiers | The Effects of Combined Low Frequency Repetitive Transcranial Magnetic Stimulation and Motor Imagery on Upper Extremity Motor Recovery Following Stroke | Neurology

Figure 1. Flow Diagram of the Trial.

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[ARTICLE] Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results – Full Text


The combination of motor imagery (MI) and afferent input with electrical stimulation (ES) enhances the excitability of the corticospinal tract compared with motor imagery alone or electrical stimulation alone. However, its therapeutic effect is unknown in patients with hemiparetic stroke. We performed a preliminary examination of the therapeutic effects of MI + ES on upper extremity (UE) motor function in patients with chronic stroke.

A total of 10 patients with chronic stroke demonstrating severe hemiparesis participated. The imagined task was extension of the affected finger. Peripheral nerve electrical stimulation was applied to the radial nerve at the spiral groove. MI + ES intervention was conducted for 10 days. UE motor function as assessed with the Fugl–Meyer assessment UE motor score (FMA-UE), the amount of the affected UE use in daily life as assessed with a Motor Activity Log (MAL-AOU), and the degree of hypertonia in flexor muscles as assessed with the Modified Ashworth Scale (MAS) were evaluated before and after intervention. To assess the change in spinal neural circuits, reciprocal inhibition between forearm extensor and flexor muscles with the H reflex conditioning-test paradigm at interstimulus intervals (ISIs) of 0, 20, and 100 ms were measured before and after intervention.

UE motor function, the amount of the affected UE use, and muscle hypertonia in flexor muscles were significantly improved after MI + ES intervention (FMA-UE: p < 0.01, MAL-AOU: p < 0.01, MAS: p = 0.02). Neurophysiologically, the intervention induced restoration of reciprocal inhibition from the forearm extensor to the flexor muscles (ISI at 0 ms: p = 0.03, ISI at 20 ms: p = 0.03, ISI at 100 ms: p = 0.01).

MI + ES intervention was effective for improving UE motor function in patients with severe paralysis.

Upper motor dysfunction is a common problem in patients with stroke and disrupts activities of daily living and eventually worsens quality of life.1,2 Recently, several rehabilitation approaches have been developed to improve upper extremity (UE) motor function. Previous research has shown that intensive use of the paretic upper limb contributes to improved motor function, even though the motor recovery period has already passed.36 However, intensive use of the paretic upper limb is impossible for patients with severe upper limb paralysis, because they cannot voluntarily control the paretic hand. Therefore, other rehabilitative approaches for severely impaired patients are needed. As an alternative approach, motor imagery (MI) can be applied to patients regardless of the degree of motor paralysis. MI is defined as a dynamic state during which the representation of a given motor act is internally rehearsed within working memory without any overt motor output.7 Functional imaging studies have revealed that brain activity during motor execution and MI is largely shared in motor networks, such as the primary motor area, supplementary motor area, and premotor area.810 Also, transcranial magnetic stimulation (TMS) studies reported that excitability of the corticospinal tract (CST) is significantly higher during MI in comparison with baseline.1115 Based on these observations, MI has been applied for rehabilitation of patients with hemiparetic stroke, and the positive therapeutic effects on UE motor function have been reported.1620 However, the effect size differs among the studies,19 and is lower with regard to motor recovery of the paretic hand.20 To obtain clinically significant improvement, ingenuity to strengthen the therapeutic effect of MI is thought to be necessary.

The combination of MI and afferent input with electrical stimulation (ES) is an approach to enhance the therapeutic effect of MI. The effectiveness of ES for modulation of the excitability of the CST and improvement of dexterity performance of the paretic hand has been reported in patients with mild to moderate paralysis.21,22 Moreover, the additive effect of MI and ES has been reported in healthy adults. Saito and colleagues reported that a combination of MI and peripheral nerve ES enhances the excitability of the CST compared with MI alone or ES alone.23 In addition, Kaneko and colleagues reported that the combination of MI and electrical muscular stimulation reproduces the excitability of the CST at levels similar to voluntary muscle contraction.24 However, its therapeutic effects for motor function in patients with stroke are unknown. Therefore, we performed a preliminary examination of the therapeutic effects of a combination of MI and peripheral nerve ES (MI + ES) on UE motor function in patients with severe paralysis. The aim of this study is to investigate the feasibility and potential of the therapeutic effect for future randomized controlled trials.[…]


Continue —> Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results – Kohei Okuyama, Miho Ogura, Michiyuki Kawakami, Kengo Tsujimoto, Kohsuke Okada, Kazuma Miwa, Yoko Takahashi, Kaoru Abe, Shigeo Tanabe, Tomofumi Yamaguchi, Meigen Liu, 2018


Figure 1. The experimental setup of the intervention with combination of motor imagery and electrical stimulation (MI + ES).

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[VIDEO] Post Concussion Syndrome – ReAttach and Mirror therapy – YouTube

This young lady had a contusio cerebri in 2014 and a concussion in 2016. In 2018 she suddenly showed sensorimotor problems after a relative small incident. This video shows the impressive improvement after one session of ReAttach to ( among others) improve the multiple sensory integration processing and to stimulate motor imagery and after the second session by means of mirror therapy.

via Post Concussion Syndrome – ReAttach and Mirror therapy – YouTube

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[Abstract] Electromyography Based Orthotic Arm and Finger Rehabilitation System


Electromyography (EMG), a technique used to analyze and record electric current produced by skeletal muscles, has been used to control replacement limbs, and diagnose muscle irregularities. In this work, an EMG based system comprising of an orthotic arm and finger device to aid in muscle rehabilitation, is presented. As the user attempts to contract their bicep or forearm muscles, the system senses the change in the EMG signals and in turn triggers the motors to assist with flexion and extension of the arm and fingers. As brain is a major factor for muscle growth, mental training using motor imagery was incorporated into the system. Subjects underwent mental training to show the capability of muscle growth. The measured data reveals that the subjects were able to compensate for the loss of muscle growth, due to shorter physical training sessions, with mental training. Subjects were then tested using the orthotic arm and finger rehabilitation device with motor imagery. The findings also showed a positive increase in muscle growth using the rehabilitation system. Based on the experimental results, the EMG rehabilitation system presented in this paper has the potential to increase muscle strength and improve the recovery rate for muscle injuries, partial paralysis, or muscle irregularities.

via Electromyography Based Orthotic Arm and Finger Rehabilitation System – IEEE Conference Publication

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[ARTICLE] BCI-Based Strategies on Stroke Rehabilitation with Avatar and FES Feedback – Full Text PDF

Stroke is the leading cause of serious and long-term disability worldwide. Some studies have shown that motor imagery (MI) based BCI has a positive effect in poststroke rehabilitation. It could help patients promote the reorganization processes in the damaged brain regions. However, offline motor imagery and conventional online motor imagery with feedback (such as rewarding sounds and movements of an avatar) could not reflect the true intention of the patients. In this study, both virtual limbs and functional electrical stimulation (FES) were used as feedback to provide patients a closed-loop sensorimotor integration for motor rehabilitation. The FES system would activate if the user was imagining hand movement of instructed side. Ten stroke patients (7 male, aged 22-70 years, mean 49.5+-15.1) were involved in this study. All of them participated in BCI-FES rehabilitation training for 4 weeks.The average motor imagery accuracies of the ten patients in the last week were 71.3%, which has improved 3% than that in the first week. Five patients’ Fugl-Meyer Assessment (FMA) scores have been raised. Patient 6, who has have suffered from stroke over two years, achieved the greatest improvement after rehabilitation training (pre FMA: 20, post FMA: 35). In the aspect of brain patterns, the active patterns of the five patients gradually became centralized and shifted to sensorimotor areas (channel C3 and C4) and premotor area (channel FC3 and FC4).In this study, motor imagery based BCI and FES system were combined to provided stoke patients with a closed-loop sensorimotor integration for motor rehabilitation. Result showed evidences that the BCI-FES system is effective in restoring upper extremities motor function in stroke. In future work, more cases are needed to demonstrate its superiority over conventional therapy and explore the potential role of MI in poststroke rehabilitation.

Download: PDF only

via [1805.04986] BCI-Based Strategies on Stroke Rehabilitation with Avatar and FES Feedback

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[Abstract] Motor imagery: a systematic review of its effectiveness in the rehabilitation of the upper limb following a stroke.



Motor imagery or mental practice of movement is a relatively new intervention that is being used on an increasingly more frequently basis in the treatment of stroke patients. It consists in the person evoking a movement or gesture in order to learn or improve its execution. Neuroimaging studies have shown that imagining movements activates neuronal patterns that are similar to those produced when they are actually performed.


A systematic review was conducted between January and June 2017 in the Web of Science, PubMed, CINHAL, PEDro and Scopus databases to select clinical trials carried out with stroke patients in whom this technique was used as rehabilitation. Thirteen randomised clinical trials were included. The characteristics of the studies and the measures of results were summarised and the evidence of their outcomes was described.


Most of the studies found significant differences in terms of improved motor rehabilitation of the upper limb among the subjects in the experimental groups. Only one of the studies failed to show any evidence of its effectiveness in isolation. None of them made any reference to its effectiveness in improving sensory alterations.


Motor imagery, combined with conventional therapy (physiotherapy or occupational therapy), seems to have positive effects on the motor rehabilitation of the upper limb following a stroke. Further research is needed to improve the heterogeneity of the interventions and to evaluate their effectiveness in the long term.


via [Motor imagery: a systematic review of its effectiveness in the rehabilitation of the upper limb following a stroke]. – PubMed – NCBI

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[ARTICLE] Effectiveness of Mirror Therapy in Rehabilitation of Hand Function in Sub-Acute Stroke – Full Text


Aim: Three quarters of strokes occur in the region supplied by the middle cerebral artery. As a consequence, the upper limb will be affected in a large number of patients. Purpose of the study is to examine the effectiveness of mirror therapy in rehabilitation of hand function in sub-acute stroke.

Methodology: An experimental study design, 30 subjects with sub-acute stroke with impaired hand function randomly allocated 15 subjects into each experimental group and conventional group. Both groups received conventional physiotherapy. The experimental group in addition, received Mirror Therapy program of 30 repetition of each exercises per day for 5 days in a week for 4 weeks (total = 20 sessions). Hand functions were measured using Upper extremity motor activity log (UE MAL) and Action research arm test (ARAT) before and after 4 week of intervention.

Results: Results of the study suggested that both the experimental and conventional group had a significant improvement in hand function (AROM, functional task with objects, object manipulation), however experimental group showed significantly more improvement than conventional group, providing Mirror Therapy with conventional treatment is more effective than conventional treatment alone.

Conclusion: Mirror therapy with conventional physiotherapy brings more improvement in hand function than conventional physiotherapy alone.


World Health Organization [WHO; Stroke; 1989] defines the clinical syndrome of stroke as ‘rapidly developed clinical signs of focal (or global) distribution of cerebral function with symptoms lasting more than 24 hours or longer or leading to death, with no apparent cause other than vascular origin’.

Prevalence rates reported for stroke or CerebroVascular Accident (CVA) worldwide vary between 500 to 800 per 100,000 population [N.K. Sehi et al 2007] with about 20 million people suffer from stroke each year; out of that 5 million will die as a consequences and 15 million will survive with long term disabilities of varied spectrum. Many surviving stroke patients will often depends on other people‘s continuous support to survive.

Stroke is the most common cause of chronic disability [1]. Of survivors, an estimated one third will be functionally dependent after 1 year experiencing difficulty with activities of daily living (ADL), ambulation, speech, and so forth [2]. Cognitive impairment occurs frequently after stroke, commonly involving memory, orientation, language, and attention. The presence of cognitive impairment in patients with stroke has important functional consequences, independent of the effects of physical impairment (T K Tatemichi et al 1994).

Recovery of function after stroke may occur, but it is unclear whether interventions can improve function beyond the spontaneous process. In particular, recovery of hand function plateaus in about 1 year, and common knowledge is that the patient will remain at that level for the rest of his or her life [3,4]. Typically in such situations, upper arm function is better than that in the hand [5]. An emerging concept in neural plasticity is that there is competition among body parts for territory in the brain [6-11].

Several studies have been conducted to examine the recovery of the hemiplegic arm in stroke patients. Up to 85% of patients show an initial deficit in the arm. Three to six months later, problems remain in 55% to 75% of patients [12-15]. While recovery of arm function is poor in a significant number of patients. Three quarters of strokes occur in the region supplied by the middle cerebral artery [16]. As a consequence, the upper limb will be affected in a large number of patients. Functional recovery of the arm includes grasping, holding, and manipulating objects, which requires the recruitment and complex integration of muscle activity from shoulder to fingers.

Functional brain imaging studies of healthy subjects suggest that excitability of the primary motor cortex ipsilateral to a unilateral hand movement is facilitated by viewing a mirror reflection of the moving hand [17]. Reorganization of motor functions immediately around the stroke site (ipsilesional) is likely to be important in motor recovery after stroke, and a contribution of other brain areas in the affected hemisphere is also possible. Activation when a subject is doing motor tasks can also occur in the bilateral inferior parietal area, the supplementary motor area, and in the premotor cortex. Furthermore, central adaptations occur in networks controlling the paretic as well as the nonparetic lower limb after stroke [18].

The aim of this study is to find the effect of mirror therapy in rehabilitation of hand function in sub-acute stroke. […]


Continue —> Effectiveness of Mirror Therapy in Rehabilitation of Hand Function in Sub-Acute Stroke

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[Abstract] Motor Imagery Training After Stroke: A Systematic Review and Meta-analysis of Randomized Controlled Trials


Background and Purpose: A number of studies have suggested that imagery training (motor imagery [MI]) has value for improving motor function in persons with neurologic conditions. We performed a systematic review and meta-analysis to assess the available literature related to efficacy of MI in the recovery of individuals after stroke.

Methods: We searched the following databases: PubMed, Web of Knowledge, Scopus, Cochrane, and PEDro. Two reviewers independently selected clinical trials that investigated the effect of MI on outcomes commonly investigated in studies of stroke recovery. Quality and risk of bias of each study were assessed.

Results: Of the 1156 articles found, 32 articles were included. There was a high heterogeneity of protocols among studies. Most studies showed benefits of MI, albeit with a large proportion of low-quality studies. The meta-analysis of all studies, regardless of quality, revealed significant differences on overall analysis for outcomes related to balance, lower limb/gait, and upper limb. However, when only high-quality studies were included, no significant difference was found. On subgroup analyses, MI was associated with balance gains on the Functional Reach Test and improved performance on the Timed Up and Go, gait speed, Action Research Arm Test, and the Fugl-Meyer Upper Limb subscale.

Discussion and Conclusions: Our review reported a high heterogeneity in methodological quality of the studies and conflicting results. More high-quality studies and greater standardization of interventions are needed to determine the value of MI for persons with stroke.

Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1,

Source: Motor Imagery Training After Stroke: A Systematic Review an… : Journal of Neurologic Physical Therapy

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[WEB SITE] ‘Games’ could help stroke, traumatic brain injury survivors regain mobility

This is a call to survivors of stroke and/or traumatic brain injury to consider demonstrating our newest ‘games’ innovations. We at 3DPreMotorSkill Technologies, LLC research and develop special video game-like technology for survivors.

We have completed two clinical trials with 47 survivors. No survivor was harmed in any way and we do not sell or charge anything for participating in our research.

Our ‘games’ benefit from a natural ability we all have: motor imagery. Motor imagery implies visualizing body movements. If you can ‘think’ of your impaired limb  making movements, our ‘games’ present virtual, controllable limbs you can use to act out your ‘thinking.’

Our first clinical trial was published in the Journal of Rehabilitation Research and Development, JRRD Volume 51, Number 3, 2014 Pages 377–390: “Pilot study: Computer-based virtual anatomical interactivity for rehabilitation of individuals with chronic acquired brain injury.”

Our second clinical trial was reported at a conference in The Netherlands (poster sections below). Our full report is under peer review by the journal Frontiers in Human Neuroscience.

Our mission is to help survivors to help themselves by ‘playing’ our self-movement-management ‘games’, called  Pre-Action Games & Exercises (PAGEs).

PAGEs are easy and fun to play. First, you see a realistic virtual limb on a computer screen. The virtual limb represents your impaired limb. You control it to make realistic physical movements. A standard computer mouse is used to point the cursor to all or part of the virtual limb and click and drag it to simulate unimpaired movements.

While controlling the virtual limb a signal is automatically sent to a wearable hand movement device (WHMD). The WHMD physically and mildly manipulates your impaired left hand. The result is mental and physical feedback to you.

A limited number of survivors (approximately five) of stroke and/or traumatic brain injury will be selected to play PAGEs games. All games are free to volunteers and will take about 30 minutes to complete, here in Tallahassee.

Candidates should:

  • be 21 years of age or older
  • have a moderate to mildly impaired (hemiparetic) left hand
  • have consulted your physician, therapist and family and be in sub-acute or less intense therapy
  • be responsible for their own consent and transportation to and from a location within Tallahassee
  • be willing to try-out for selection (approximately 15 minutes).
  • All we need for the selection try-out is you and an aide, if you like. Please email interest to and be sure to add “WHMD” to the “Subject:” line, so that your response is read. Send any details you wish, such as left hand impairment and date of brain injury. 

Source: ‘Games’ could help stroke, traumatic brain injury survivors

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[ARTICLE] Post-stroke Rehabilitation Training with a Motor-Imagery-Based Brain-Computer Interface (BCI)-Controlled Hand Exoskeleton: A Randomized Controlled Multicenter Trial – Full Text

Repeated use of brain-computer interfaces (BCIs) providing contingent sensory feedback of brain activity was recently proposed as a rehabilitation approach to restore motor function after stroke or spinal cord lesions. However, there are only a few clinical studies that investigate feasibility and effectiveness of such an approach. Here we report on a placebo-controlled, multicenter clinical trial that investigated whether stroke survivors with severe upper limb (UL) paralysis benefit from 10 BCI training sessions each lasting up to 40 min. A total of 74 patients participated: median time since stroke is 8 months, 25 and 75% quartiles [3.0; 13.0]; median severity of UL paralysis is 4.5 points [0.0; 30.0] as measured by the Action Research Arm Test, ARAT, and 19.5 points [11.0; 40.0] as measured by the Fugl-Meyer Motor Assessment, FMMA. Patients in the BCI group (n = 55) performed motor imagery of opening their affected hand. Motor imagery-related brain electroencephalographic activity was translated into contingent hand exoskeleton-driven opening movements of the affected hand. In a control group (n = 19), hand exoskeleton-driven opening movements of the affected hand were independent of brain electroencephalographic activity. Evaluation of the UL clinical assessments indicated that both groups improved, but only the BCI group showed an improvement in the ARAT’s grasp score from 0 [0.0; 14.0] to 3.0 [0.0; 15.0] points (p < 0.01) and pinch scores from 0.0 [0.0; 7.0] to 1.0 [0.0; 12.0] points (p < 0.01). Upon training completion, 21.8% and 36.4% of the patients in the BCI group improved their ARAT and FMMA scores respectively. The corresponding numbers for the control group were 5.1% (ARAT) and 15.8% (FMMA). These results suggests that adding BCI control to exoskeleton-assisted physical therapy can improve post-stroke rehabilitation outcomes. Both maximum and mean values of the percentage of successfully decoded imagery-related EEG activity, were higher than chance level. A correlation between the classification accuracy and the improvement in the upper extremity function was found. An improvement of motor function was found for patients with different duration, severity and location of the stroke.


Motor imagery (Page et al., 2001), or mental practice, attracted considerable interest as a potential neurorehabilitation technique improving motor recovery following stroke (Jackson et al., 2001). According to the Guidelines for adult stroke rehabilitation and recovery (Winstein et al., 2016), mental practice may proof beneficial as an adjunct to upper extremity rehabilitation services (Winstein et al., 2016). Several studies suggest that motor imagery can trigger neuroplasticity in ipsilesional motor cortical areas despite severe paralysis after stroke (Grosse-Wentrup et al., 2011Shih et al., 2012Mokienko et al., 2013bSoekadar et al., 2015).

The effect of motor imagery on motor function and neuroplasticity has been demonstrated in numerous neurophysiological studies in healthy subjects. Motor imagery has been shown to activate the primary motor cortex (M1) and brain structures involved in planning and control of voluntary movements (Shih et al., 2012Mokienko et al., 2013a,bFrolov et al., 2014). For example, it was shown that motor imagery of fist clenching reduces the excitation threshold of motor evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) delivered to M1 (Mokienko et al., 2013b).

As motor imagery results in specific modulations of brain electroencephalographic (EEG) signals, e.g., sensorimotor rhythms (SMR) (Pfurtscheller and Aranibar, 1979), it can be used to voluntarily control an external device, e.g., a robot or exoskeleton using a brain-computer interface (BCI) (Nicolas-Alonso and Gomez-Gil, 2012). Such system allowing for voluntary control of an exoskeleton moving a paralyzed limb can be used as an assistive device restoring lost function (Maciejasz et al., 2014). Besides receiving visual feedback, the user receives haptic and kinesthetic feedback which is contingent upon the imagination of a specific movement.

Several BCI studies involving this type of haptic and kinesthetic feedback have demonstrated improvements in clinical parameters of post-stroke motor recovery (Ramos-Murguialday et al., 2013Ang et al., 20142015Ono et al., 2014). The number of subjects with post-stroke upper extremity paresis included in these studies was, however, relatively low [from 12 (Ono et al., 2014) to 32 (Ramos-Murguialday et al., 2013) patients]. As BCI-driven external devices, a haptic knob (Ang et al., 2014), MIT-Manus (Ang et al., 2015), or a custom-made orthotic device (Ramos-Murguialday et al., 2013Ono et al., 2014) were used. Furthermore, several other studies reported on using BCI-driven exoskeletons in patients with post-stroke hand paresis (Biryukova et al., 2016Kotov et al., 2016Mokienko et al., 2016), but these reports did not test for clinical efficacy and did not include a control group. While very promising, it still remains unclear whether BCI training is an effective tool to facilitate motor recovery after stroke or other lesions of the central nervous system (CNS) (Teo and Chew, 2014).

Here we report a randomized and controlled multicenter study investigating whether 10 sessions of BCI-controlled hand-exoskeleton active training after subacute and chronic stroke yields a better clinical outcome than 10 sessions in which hand-exoskeleton induced passive movements were not controlled by motor imagery-related modulations of brain activity. Besides assessing the effect of BCI training on clinical scores such as the ARAT and FMMA, we tested whether improvements in the upper extremity function correlates with the patient’s ability to generate motor imagery-related modulations of EEG activity.[…]

Continue —> Frontiers | Post-stroke Rehabilitation Training with a Motor-Imagery-Based Brain-Computer Interface (BCI)-Controlled Hand Exoskeleton: A Randomized Controlled Multicenter Trial | Neuroscience


Figure 1. The subject flow diagram from recruitment through analysis (Consolidated Standards of Reporting Trials flow diagram).

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