Brain-machine Interface (BMI)-based Neurorehabilitation for Post-stroke Upper Limb Paralysis.

Because recovery from upper limb paralysis after stroke is challenging, compensatory approaches have been the main focus of upper limb rehabilitation. However, based on fundamental and clinical research indicating that the brain has a far greater potential for plastic change than previously thought, functional restorative approaches have become increasingly common. Among such interventions, constraint-induced movement therapy, task-specific training, robotic therapy, neuromuscular electrical stimulation (NMES), mental practice, mirror therapy, and bilateral arm training are recommended in recently published stroke guidelines. For severe upper limb paralysis, however, no effective therapy has yet been established. Against this background, there is growing interest in applying brain-machine interface (BMI) technologies to upper limb rehabilitation. Increasing numbers of randomized controlled trials have demonstrated the effectiveness of BMI neurorehabilitation, and several meta-analyses have shown medium to large effect sizes with BMI therapy. Subgroup analyses indicate higher intervention effects in the subacute group than the chronic group, when using movement attempts as the BMI-training trigger task rather than using motor imagery, and using NMES as the external device compared with using other devices. The Keio BMI team has developed an electroencephalography-based neurorehabilitation system and has published clinical and basic studies demonstrating its effectiveness and neurophysiological mechanisms. For its wider clinical application, the positioning of BMI therapy in upper limb rehabilitation needs to be clarified, BMI needs to be commercialized as an easy-to-use and cost-effective medical device, and training systems for rehabilitation professionals need to be developed. A technological breakthrough enabling selective modulation of neural circuits is also needed.

The neural correlates of gait improvement by rhythmic sound stimulation in adults with Parkinson's disease - A functional magnetic resonance imaging study.

INTRODUCTION: Adults with Parkinson's disease (PD) experience gait disturbances that can sometimes be improved with rhythmic auditory stimulation (RAS); however, the underlying physiological mechanism for this improvement is not well understood. We investigated brain activation patterns in adults with PD and healthy controls (HC) using functional magnetic resonance imaging (fMRI) while participants imagined gait with or without RAS. METHODS: Twenty-seven adults with PD who could walk independently and walked more smoothly with rhythmic auditory cueing than without it, and 25 age-matched HC participated in this study. Participants imagined gait in the presence of RAS or white noise (WN) during fMRI. RESULTS: In the PD group, gait imagery with RAS activated cortical motor areas, including supplementary motor areas and the cerebellum, while gait imagery with WN additionally recruited the left parietal operculum. In HC, the induced activation was limited to cortical motor areas and the cerebellum for both the RAS and WN conditions. Within- and between-group analyses demonstrated that RAS reduced the activity of the left parietal operculum in the PD group but not in the HC group (condition-by-group interaction by repeated measures analysis of variance, p < 0.05). CONCLUSION: During gait imagery in adults with PD, the left parietal operculum was less activated by RAS than by WN, while no change was observed in HC, suggesting that rhythmic auditory stimulation may support the sensory-motor networks involved in gait, thus alleviating the overload of the parietal operculum and compensating for its dysfunction in these patients.

Effects of hybrid assistive neuromuscular dynamic stimulation therapy for hemiparesis after pediatric stroke: a feasibility trial.

BACKGROUND: Hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy, consisting of a wrist-hand splint and an integrated volitional control electrical stimulator to stimulate the extensor digitorum communis, is effective for chronic hemiparesis after stroke in adults. We investigated the feasibility and effects of HANDS therapy for patients with pediatric stroke by performing a longitudinal study. METHODS: Twelve patients with chronic hemiparetic pediatric stroke (aged 14-38 years) wore the herapeutic device for 3 weeks. The device was active for 8 h during the daytime, and patients were instructed to use their paretic hand as much as possible. Upper extremity items of the Fugl-Meyer Motor Assessment Scale and the Stroke Impairment Assessment Set motor test were used to measure motor function and were compared before and after the intervention with the Wilcoxon signed rank test. RESULTS: All patients were fully compliant with the therapy with no adverse events. After the intervention, both treatment endpoints improved significantly (p < .05). The effect size for upper extremity items of the Fugl-Meyer Motor Assessment Scale was medium (d = 0.59). CONCLUSION: This preliminary study demonstrated the feasibility and effectiveness of HANDS therapy in patients with pediatric stroke.Implications for rehabilitationPediatric stroke is a very rare disease and patients are forced to live with sequelae in most of the rest of their lives.Hybrid assistive neuromuscular dynamic stimulation therapy is effective for upper limb paralysis of adult stroke.Hybrid assistive neuromuscular dynamic stimulation therapy was adaptable even for children, and improvement of upper limb paralysis was observed even in a relatively short period of intervention.

Kinesthetic illusion induced by visual stimulation influences sensorimotor event-related desynchronization in stroke patients with severe upper-limb paralysis: A pilot study.

BACKGROUND: Repetition of motor imagery improves the motor function of patients with stroke. However, patients who develop severe upper-limb paralysis after chronic stroke often have an impaired ability to induce motor imagery. We have developed a method to passively induce kinesthetic perception using visual stimulation (kinesthetic illusion induced by visual stimulation [KINVIS]). OBJECTIVE: This pilot study further investigated the effectiveness of KINVIS in improving the induction of kinesthetic motor imagery in patients with severe upper-limb paralysis after stroke. METHODS: Twenty participants (11 with right hemiplegia and 9 with left hemiplegia; mean time from onset [±standard deviation], 67.0±57.2 months) with severe upper-limb paralysis who could not extend their paretic fingers were included in this study. The ability to induce motor imagery was evaluated using the event-related desynchronization (ERD) recorded during motor imagery before and after the application of KINVIS for 20 min. The alpha- and beta-band ERDs around the premotor, primary sensorimotor, and posterior parietal cortices of the affected and unaffected hemispheres were evaluated during kinesthetic motor imagery of finger extension and before and after the intervention. RESULTS: Beta-band ERD recorded from the affected hemisphere around the sensorimotor area showed a significant increase after the intervention, while the other ERDs remained unchanged. CONCLUSIONS: In patients with chronic stroke who were unable to extend their paretic fingers for a prolonged period of time, the application of KINVIS, which evokes kinesthetic perception, improved their ability to induce motor imagery. Our findings suggest that although KINVIS is a passive intervention, its short-term application can induce changes related to the motor output system.

Sensorimotor Connectivity after Motor Exercise with Neurofeedback in Post-Stroke Patients with Hemiplegia.

Impaired finger motor function in post-stroke hemiplegia is a debilitating condition with no evidence-based or accessible treatments. Here, we evaluated the neurophysiological effectiveness of direct brain control of robotic exoskeleton that provides movement support contingent with brain activity. To elucidate the mechanisms underlying the neurofeedback intervention, we assessed resting-state functional connectivity with functional magnetic resonance imaging (rsfcMRI) between the ipsilesional sensory and motor cortices before and after a single 1-h intervention. Eighteen stroke patients were randomly assigned to crossover interventions in a double-blind and sham-controlled design. One patient dropped out midway through the study, and 17 patients were included in this analysis. Interventions involved motor imagery, robotic assistance, and neuromuscular electrical stimulation administered to a paretic finger. The neurofeedback intervention delivered stimulations contingent on desynchronized ipsilesional electroencephalographic (EEG) oscillations during imagined movement, and the control intervention delivered sensorimotor stimulations that were independent of EEG oscillations. There was a significant time × intervention interaction in rsfcMRI in the ipsilesional sensorimotor cortex. Post-hoc analysis showed a larger gain in increased functional connectivity during the neurofeedback intervention. Although the neurofeedback intervention delivered fewer total sensorimotor stimulations compared to the sham-control, rsfcMRI in the ipsilesional sensorimotor cortices was increased during the neurofeedback intervention compared to the sham-control. Higher coactivation of the sensory and motor cortices during neurofeedback intervention enhanced rsfcMRI in the ipsilesional sensorimotor cortices. This study showed neurophysiological evidence that EEG-contingent neurofeedback is a promising strategy to induce intrinsic ipsilesional sensorimotor reorganization, supporting the importance of integrating closed-loop sensorimotor processing at a neurophysiological level.

Evaluating the Effectiveness and Safety of the Electroencephalogram-Based Brain-Machine Interface Rehabilitation System for Patients With Severe Hemiparetic Stroke: Protocol for a Randomized Controlled Trial (BEST-BRAIN Trial).

BACKGROUND: We developed a brain-machine interface (BMI) system for poststroke patients with severe hemiplegia to detect event-related desynchronization (ERD) on scalp electroencephalogram (EEG) and to operate a motor-driven hand orthosis combined with neuromuscular electrical stimulation. ERD arises when the excitability of the ipsi-lesional sensorimotor cortex increases. OBJECTIVE: The aim of this study was to evaluate our hypothesis that motor training using this BMI system could improve severe hemiparesis that is resistant to improvement by conventional rehabilitation. We, therefore, planned and implemented a randomized controlled clinical trial (RCT) to evaluate the effectiveness and safety of intensive rehabilitation using the BMI system. METHODS: We conducted a single blind, multicenter RCT and recruited chronic poststroke patients with severe hemiparesis more than 90 days after onset (N=40). Participants were randomly allocated to the BMI group (n=20) or the control group (n=20). Patients in the BMI group repeated 10-second motor attempts to operate EEG-BMI 40 min every day followed by 40 min of conventional occupational therapy. The interventions were repeated 10 times in 2 weeks. Control participants performed a simple motor imagery without servo-action of the orthosis, and electrostimulation was given for 10 seconds for 40 min, similar to the BMI intervention. Overall, 40 min of conventional occupational therapy was also given every day after the control intervention, which was also repeated 10 times in 2 weeks. Motor functions and electrophysiological phenotypes of the paretic hands were characterized before (baseline), immediately after (post), and 4 weeks after (follow-up) the intervention. Improvement in the upper extremity score of the Fugl-Meyer assessment between baseline and follow-up was the main outcome of this study. RESULTS: Recruitment started in March 2017 and ended in July 2018. This trial is currently in the data correcting phase. This RCT is expected to be completed by October 31, 2018. CONCLUSIONS: No widely accepted intervention has been established to improve finger function of chronic poststroke patients with severe hemiparesis. The results of this study will provide clinical data for regulatory approval and novel, important understanding of the role of sensory-motor feedback based on BMI to induce neural plasticity and motor recovery. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000026372; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi? recptno=R000030299 (Archived by WebCite at http://www.webcitation.org/743zBJj3D). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12339.

Change in Reciprocal Inhibition of the Forearm with Motor Imagery among Patients with Chronic Stroke.

We investigated cortically mediated changes in reciprocal inhibition (RI) following motor imagery (MI) in short- and long(er)-term periods. The goals of this study were (1) to describe RI during MI in patients with chronic stroke and (2) to examine the change in RI after MI-based brain-machine interface (BMI) training. Twenty-four chronic stroke patients participated in study 1. All patients imagined wrist extension on the affected side. RI from the extensor carpi radialis to the flexor carpi radialis (FCR) was assessed using a FCR H reflex conditioning-test paradigm. We calculated the "MI effect score on RI" (RI value during MI divided by that at rest) and compared that score according to lesion location. RI during MI showed a significant enhancement compared with RI at rest. The MI effect score on RI in the subcortical lesion group was significantly greater than that in the cortical lesion group. Eleven stroke patients participated in study 2. All patients performed BMI training for 10 days. The MI effect score on RI at a 20 ms interstimulus interval was significantly increased after BMI compared with baseline. In conclusion, mental practice with MI may induce plastic change in spinal reciprocal inhibitory circuits in patients with stroke.

Ipsilateral EEG mu rhythm reflects the excitability of uncrossed pathways projecting to shoulder muscles.

BACKGROUND: Motor planning, imagery or execution is associated with event-related desynchronization (ERD) of mu rhythm oscillations (8-13 Hz) recordable over sensorimotor areas using electroencephalography (EEG). It was shown that motor imagery involving distal muscles, e.g. finger movements, results in contralateral ERD correlating with increased excitability of the contralateral corticospinal tract (c-CST). Following the rationale that purposefully increasing c-CST excitability might facilitate motor recovery after stroke, ERD recently became an attractive target for brain-computer interface (BCI)-based neurorehabilitation training. It was unclear, however, whether ERD would also reflect excitability of the ipsilateral corticospinal tract (i-CST) that mainly innervates proximal muscles involved in e.g. shoulder movements. Such knowledge would be important to optimize and extend ERD-based BCI neurorehabilitation protocols, e.g. to restore shoulder movements after stroke. Here we used single-pulse transcranial magnetic stimulation (TMS) targeting the ipsilateral primary motor cortex to elicit motor evoked potentials (MEPs) of the trapezius muscle. To assess whether ERD reflects excitability of the i-CST, a correlation analysis between between MEP amplitudes and ipsilateral ERD was performed. METHODS: Experiment 1 consisted of a motor execution task during which 10 healthy volunteers performed elevations of the shoulder girdle or finger pinching while a 128-channel EEG was recorded. Experiment 2 consisted of a motor imagery task during which 16 healthy volunteers imagined shoulder girdle elevations or finger pinching while an EEG was recorded; the participants simultaneously received randomly timed, single-pulse TMS to the ipsilateral primary motor cortex. The spatial pattern and amplitude of ERD and the amplitude of the agonist muscle's TMS-induced MEPs were analyzed. RESULTS: ERDs occurred bilaterally during both execution and imagery of shoulder girdle elevations, but were lateralized to the contralateral hemisphere during finger pinching. We found that trapezius MEPs increased during motor imagery of shoulder elevations and correlated with ipsilateral ERD amplitudes. CONCLUSIONS: Ipsilateral ERD during execution and imagery of shoulder girdle elevations appears to reflect the excitability of uncrossed pathways projecting to the shoulder muscles. As such, ipsilateral ERD could be used for neurofeedback training of shoulder movement, aiming at reanimation of the i-CST.

A new therapeutic application of brain-machine interface (BMI) training followed by hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy for patients with severe hemiparetic stroke: A proof of concept study.

BACKGROUND: Hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy improved paretic upper extremity motor function in patients with severe to moderate hemiparesis. We hypothesized that brain machine interface (BMI) training would be able to increase paretic finger muscle activity enough to apply HANDS therapy in patients with severe hemiparesis, whose finger extensor was absent. OBJECTIVE: The aim of this study was to assess the efficacy of BMI training followed by HANDS therapy in patients with severe hemiparesis. METHODS: Twenty-nine patients with chronic stroke who could not extend their paretic fingers were participated this study. We applied BMI training for 10 days at 40 min per day. The BMI detected the patients' motor imagery of paretic finger extension with event-related desynchronization (ERD) over the affected primary sensorimotor cortex, recorded with electroencephalography. Patients wore a motor-driven orthosis, which extended their paretic fingers and was triggered with ERD. When muscle activity in their paretic fingers was detected with surface electrodes after 10 days of BMI training, we applied HANDS therapy for the following 3 weeks. In HANDS therapy, participants received closed-loop, electromyogram-controlled, neuromuscular electrical stimulation (NMES) combined with a wrist-hand splint for 3 weeks at 8 hours a day. Before BMI training, after BMI training, after HANDS therapy and 3month after HANDS therapy, we assessed Fugl-Meyer Assessment upper extremity motor score (FMA) and the Motor Activity Log14-Amount of Use (MAL-AOU) score. RESULTS: After 10 days of BMI training, finger extensor activity had appeared in 21 patients. Eighteen of 21 patients then participated in 3 weeks of HANDS therapy. We found a statistically significant improvement in the FMA and the MAL-AOU scores after the BMI training, and further improvement was seen after the HANDS therapy. CONCLUSION: Combining BMI training with HANDS therapy could be an effective therapeutic strategy for severe UE paralysis after stroke.

The effects of anodal transcranial direct current stimulation and patterned electrical stimulation on spinal inhibitory interneurons and motor function in patients with spinal cord injury.

Supraspinal excitability and sensory input may play an important role for the modulation of spinal inhibitory interneurons and functional recovery among patients with incomplete spinal cord injury (SCI). Here, we investigated the effects of anodal transcranial direct current stimulation (tDCS) combined with patterned electrical stimulation (PES) on spinal inhibitory interneurons in patients with chronic incomplete SCI and in healthy individuals. Eleven patients with incomplete SCI and ten healthy adults participated in a single-masked, sham-controlled crossover study. PES involved stimulating the common peroneal nerve with a train of ten 100 Hz pulses every 2 s for 20 min. Anodal tDCS (1 mA) was simultaneously applied to the primary motor cortex that controls the tibialis anterior muscle. We measured reciprocal inhibition and presynaptic inhibition of a soleus H-reflex by stimulating the common peroneal nerve prior to tibial nerve stimulation, which elicits the H-reflex. The inhibition was assessed before, immediately after, 10 min after and 20 min after the stimulation. Compared with baseline, simultaneous application of anodal tDCS with PES significantly increased changes in disynaptic reciprocal inhibition and long-latency presynaptic inhibition in both healthy and SCI groups for at least 20 min after the stimulation (all, p < 0.001). In patients with incomplete SCI, anodal tDCS with PES significantly increased the number of ankle movements in 10 s at 20 min after the stimulation (p = 0.004). In conclusion, anodal tDCS combined with PES could induce spinal plasticity and improve ankle movement in patients with incomplete SCI.

Modulation of cortical and spinal inhibition with functional recovery of upper extremity motor function among patients with chronic stroke.

PURPOSE: We hypothesized that recovery of upper extremity motor function is associated with reduction of intracortical inhibition and improved reciprocal inhibition. This study examines the relationships of functional recovery in chronic stroke with the intracortical inhibition and spinal reciprocal inhibition. METHODS: Participants were 61 patients with chronic hemiparetic stroke. The participants were applied hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy for 3 weeks. The Fugl-Meyer test upper extremity motor score (FM) and modified Ashworth scale (MAS) were assessed before (T0), immediately after (T1) and 3 months after (T2) the end of HANDS therapy. A paired pulse TMS paradigm was applied to assess short intracortical inhibition (SICI). Reciprocal inhibition (RI) was assessed with H reflex conditioning-test paradigm. RESULTS: FM and MAS were improved until T2. The change of FM from T0 to T2 was positively correlated with the change in affected SICI from T0 toT1. The change of wrist MAS from T0 to T1 was positively correlated with the change of RI. CONCLUSIONS: In chronic stroke patients with moderate or severe hemiparesis, well-recovered patients showed disinhibition of ipsilesional hemisphere and increased resiprocal inhibition of forearm.

Functional recovery from chronic writer's cramp by brain-computer interface rehabilitation: a case report.

BACKGROUND: Dystonia is often currently treated with botulinum toxin injections to spastic muscles, or deep brain stimulation to the basal ganglia. In addition to these pharmacological or neurosurgical measures, a new noninvasive treatment concept, functional modulation using a brain-computer interface, was tested for feasibility. We recorded electroencephalograms (EEGs) over the bilateral sensorimotor cortex from a patient suffering from chronic writer's cramp. The patient was asked to suppress an exaggerated beta frequency component in the EEG during hand extension. RESULTS: The patient completed biweekly one-hour training for 5 months without any adverse effects. Significant decrease of the beta frequency component during handwriting was confirmed, and was associated with clear functional improvement. CONCLUSION: The current pilot study suggests that a brain-computer Interface can give explicit feedback of ongoing cortical excitability to patients with dystonia and allow them to suppress exaggerated neural activity, resulting in functional recovery.

A pilot study of sensory feedback by transcutaneous electrical nerve stimulation to improve manipulation deficit caused by severe sensory loss after stroke.

BACKGROUND: Sensory disturbance is common following stroke and can exacerbate functional deficits, even in patients with relatively good motor function. In particular, loss of appropriate sensory feedback in severe sensory loss impairs manipulation capability. We hypothesized that task-oriented training with sensory feedback assistance would improve manipulation capability even without sensory pathway recovery. METHODS: We developed a system that provides sensory feedback by transcutaneous electrical nerve stimulation (SENS) for patients with sensory loss, and investigated the feasibility of the system in a stroke patient with severe sensory impairment and mild motor deficit. The electrical current was modulated by the force exerted by the fingertips so as to allow the patient to identify the intensity. The patient had severe sensory loss due to a right thalamic hemorrhage suffered 27 months prior to participation in the study. The patient first practiced a cylindrical grasp task with SENS for 1 hour daily over 29 days. Pressure information from the affected thumb was fed back to the unaffected shoulder. The same patient practiced a tip pinch task with SENS for 1 hour daily over 4 days. Pressure information from the affected thumb and index finger was fed back to the unaffected and affected shoulders, respectively. We assessed the feasibility of SENS and examined the improvement of manipulation capability after training with SENS. RESULTS: The fluctuation in fingertip force during the cylindrical grasp task gradually decreased as the training progressed. The patient was able to maintain a stable grip force after training, even without SENS. Pressure exerted by the tip pinch of the affected hand was unstable before intervention with SENS compared with that of the unaffected hand. However, they were similar to each other immediately after SENS was initiated, suggesting that the somatosensory information improved tip pinch performance. The patient's manipulation capability assessed by the Box and Block Test score improved through SENS intervention and was partly maintained after SENS was removed, until at least 7 months after the intervention. The sensory test score, however, showed no recovery after intervention. CONCLUSIONS: We conclude that the proposed system would be useful in the rehabilitation of patients with sensory loss.

Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.

While previous studies have assessed changes in corticospinal excitability following voluntary contraction coupled with electrical stimulation (ES), we sought to examine, for the first time in the field, real-time changes in corticospinal excitability. We monitored motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and recorded the MEPs using a mechanomyogram, which is less susceptible to electrical artifacts. We assessed the MEPs at each level of muscle contraction of wrist flexion (0%, 5%, or 20% of maximum voluntary contraction) during voluntary wrist flexion (flexor carpi radialis (FCR) voluntary contraction), either with or without simultaneous low-frequency (10 Hz) ES of the median nerve that innervates the FCR. The stimulus intensity corresponded to 1.2 × perception threshold. In the FCR, voluntary contraction with median nerve stimulation significantly increased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.01). In addition, corticospinal excitability was significantly modulated by the level of FCR voluntary contraction. In contrast, in the extensor carpi radialis (ECR), FCR voluntary contraction with median nerve stimulation significantly decreased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.05). Thus, median nerve stimulation during FCR voluntary contraction induces reciprocal changes in cortical excitability in agonist and antagonist muscles. Finally we also showed that even mental imagery of FCR voluntary contraction with median nerve stimulation induced the same reciprocal changes in cortical excitability in agonist and antagonist muscles. Our results support the use of voluntary contraction coupled with ES in neurorehabilitation therapy for patients.

A pilot study of contralateral homonymous muscle activity simulated electrical stimulation in chronic hemiplegia.

OBJECTIVE: For the recovery of hemiparetic hand function, a therapy was developed called contralateral homonymous muscle activity stimulated electrical stimulation (CHASE), which combines electrical stimulation and bilateral movements, and its feasibility was studied in three chronic stroke patients with severe hand hemiparesis. METHODS: Patients with a subcortical lesion were asked to extend their wrist and fingers bilaterally while an electromyogram (EMG) was recorded from the extensor carpi radialis (ECR) muscle in the unaffected hand. Electric stimulation was applied to the homonymous wrist and finger extensors of the affected side. The intensity of the electrical stimulation was computed based on the EMG and scaled so that the movements of the paretic hand looked similar to those of the unaffected side. The patients received 30-minutes of therapy per day for 2 weeks. RESULTS: Improvement in the active range of motion of wrist extension was observed for all patients. There was a decrease in the scores of modified Ashworth scale in the flexors. Fugl-Meyer assessment scores of motor function of the upper extremities improved in two of the patients. CONCLUSIONS: The results suggest a positive outcome can be obtained using the CHASE system for upper extremity rehabilitation of patients with severe hemiplegia.

Immediate effects of electrical stimulation combined with passive locomotion-like movement on gait velocity and spasticity in persons with hemiparetic stroke: a randomized controlled study.

OBJECTIVE: Research to examine the immediate effects of electrical stimulation combined with passive locomotion-like movement on gait velocity and spasticity. DESIGN: A single-masked, randomized controlled trial design. SUBJECTS: Twenty-seven stroke inpatients in subacute phase (ischemic n = 16, hemorrhagic n = 11). INTERVENTIONS: A novel approach using electrical stimulation combined with passive locomotion-like movement. MAIN MEASURES: We assessed the maximum gait speed and modified Ashworth scale before and 20 minutes after the interventions. RESULTS: The gait velocity of the electrical stimulation combined with passive locomotion-like movement group showed the increase form 0.68 ± 0.28 (mean ± SD, unit: m) to 0.76 ± 0.32 after the intervention. Both the electrical stimulation group and passive locomotion-like movement group also showed increases after the interventions (from 0.76 ± 0.37 to 0.79 ± 0.40, from 0.74 ± 0.35 to 0.77 ± 0.36, respectively). The gait velocity of the electrical stimulation combined with passive locomotion-like movement group differed significantly from those of the other groups (electrical stimulation combined with passive locomotion-like movement versus electrical stimulation: P = 0.049, electrical stimulation combined with passive locomotion-like movement versus passive locomotion-like movement: P = 0.025). Although there was no statistically significant difference in the modified Ashworth scale among the three groups, six of the nine subjects (66.6%) in the electrical stimulation combined with passive locomotion-like movement group showed improvement in the modified Ashworth scale score, while only three of the nine subjects (33.3%) in the electrical stimulation group and two of the nine subjects (22.2%) improved in the passive locomotion-like movement group. CONCLUSION: These findings suggest electrical stimulation combined with passive locomotion-like movement could improve gait velocity in stroke patients.

Modulation of event-related desynchronization during motor imagery with transcranial direct current stimulation in a patient with severe hemiparetic stroke: a case report.

Recently, surface electroencephalogram (EEG)-based brain-machine interfaces (BMI) have been used for people with disabilities. As a BMI signal source, event-related desynchronization of alpha-band EEG (8-13 Hz) during motor imagery (mu ERD), which is interpreted as desynchronized activities of the activated neurons, is commonly used. However, it is often difficult for patients with severe hemiparesis to produce mu ERD of sufficient strength to activate BMI. Therefore, whether it is possible to modulate mu ERD during motor imagery with anodal transcranial direct-current stimulation (tDCS) was assessed in a severe left hemiparetic stroke patient. EEG was recorded over the primary motor cortex (M1), and mu ERD during finger flexion imagery was measured before and after a 5-day course of tDCS applied to M1. The ERD recorded over the affected M1 increased significantly after tDCS intervention. Anodal tDCS may increase motor cortex excitability and potentiate ERD during motor imagery in patients with severe hemiparetic stroke.

Effects of integrated volitional control electrical stimulation (IVES) on upper extremity function in chronic stroke.

We evaluated the efficacy of a novel electromyogram (EMG)-controlled electrical stimulation system, called the integrated volitional control electrical stimulator (IVES), on the recovery of upper extremity motor functions in patients with chronic hemiparetic stroke. Ten participants in the chronic stage (more than 12 months post-stroke with partial paralysis of their wrist and fingers) received treatment with IVES to the extensor carpi radialis and extensor digitorum communis 6 h/day for 5 days. Before and after the intervention, participants were assessed using upper-extremity Fugl-Meyer motor assessment (FMA), the active range of motion (A-ROM), the nine-hole peg test (NHPT), and surface EMG recordings. The upper extremity FMA showed a statistically significant increase from 50.8 ± 5.8 to 56.8 ± 6.2 after the intervention (P < 0.01). The A-ROM of wrist extension was also significantly improved from 36.0° ± 15.4° to 45.0° ± 15.5° (P < 0.01). The NHPT significantly decreased from 85.3 ± 52.0 to 63.3 ± 29.7 (P = 0.04). EMG measurements demonstrated statistically significant improvements in the coactivation ratios for the wrist flexor and extensor muscles after the intervention. This study suggested that 5 days of IVES treatment yields a noticeable improvement in upper extremity motor functions in patients with chronic hemiparetic stroke.

Effects of neurofeedback training with an electroencephalogram-based brain-computer interface for hand paralysis in patients with chronic stroke: a preliminary case series study.

OBJECTIVE: To explore the effectiveness of neurorehabilitative training using an electroencephalogram-based brain- computer interface for hand paralysis following stroke. DESIGN: A case series study. SUBJECTS: Eight outpatients with chronic stroke demonstrating moderate to severe hemiparesis. METHODS: Based on analysis of volitionally decreased amplitudes of sensory motor rhythm during motor imagery involving extending the affected fingers, real-time visual feedback was provided. After successful motor imagery, a mechanical orthosis partially extended the fingers. Brain-computer interface interventions were carried out once or twice a week for a period of 4-7 months, and clinical and neurophysiological examinations pre- and post-intervention were compared. RESULTS: New voluntary electromyographic activity was measured in the affected finger extensors in 4 cases who had little or no muscle activity before the training, and the other participants exhibited improvement in finger function. Significantly greater suppression of the sensory motor rhythm over both hemispheres was observed during motor imagery. Transcranial magnetic stimulation showed increased cortical excitability in the damaged hemisphere. Success rates of brain-computer interface training tended to increase as the session progressed in 4 cases. CONCLUSION: Brain-computer interface training appears to have yielded some improvement in motor function and brain plasticity. Further controlled research is needed to clarify the role of the brain-computer interface system.