Electroencephalographic sensorimotor rhythms are modulated in the acute phase following focal vibration in healthy subjects

A single exposure to prolonged flexor carpi radialis muscle vibration increases sensorimotor cortical areas activity

Prolonged local vibration (LV) is thought to promote brain plasticity through repeated Ia afferents discharge. However, the underlying mechanisms remain unclear. This study therefore aimed at determining the acute after-effects of 30-min LV of the flexor carpi radialis muscle (FCR) on sensorimotor (S1, M1) and posterior parietal cortex (PPC) areas activity. Sixteen healthy participants were tested before and immediately after 30 min of FCR LV. Electroencephalographic signals were recorded during isometric submaximal wrist flexions. Time-frequency analyses were performed at source levels during contraction preparation, contraction initiation, force plateau, and relaxation. After LV, the results showed an increase in α and β desynchronizations in the source activity for the estimated M1, S1, and PPC during contraction preparation (P ≤ 0.05) and contraction initiation (P ≤ 0.05; except for PPC in the β band: P = 0.07), and a greater α desynchronization in M1, S1, and PPC (P < 0.01) during force plateau. No LV-induced changes were observed during relaxation. Prolonged LV on the upper limb could increase estimated cortical activity within M1, S1, and PPC areas during subsequent isometric contractions. This could be due to LV-induced Ia afferents inputs projecting onto cortical areas through proprioceptive pathways, and likely triggering brain use-dependent plasticity.NEW & NOTEWORTHY Prolonged local vibration (LV) is thought to promote brain plasticity, yet the underlying mechanisms remain unclear. In the present study, we used electroencephalography in healthy subjects and found increased activity in primary motor, primary somatosensory, and posterior parietal areas after a single exposure to LV. This may be due to LV-induced Ia afferents inputs projecting onto cortical areas through proprioceptive pathways, and likely triggering brain plasticity.

The effect of vibration-hinged ankle foot orthoses on gait and spasticity in children with cerebral palsy: A randomized clinical trial design

BACKGROUND

Hinged ankle foot orthoses (HAFO) are commonly prescribed for children with cerebral palsy (CP) to improve their ambulatory function.

OBJECTIVES

The aim of this study was to compare the effect of vibration-HAFO with that of the same orthosis without vibration on gait, function, and spasticity in hemiplegic CP children.

STUDY DESIGN

Randomized Control Trial Design (a pilot study).

METHODS

Twenty-three children with hemiplegic CP participated in this study. The control group (n = 12) used HAFO, and the intervention group (n = 11) used vibration-HAFO for four weeks. Pre-post three-dimensional gait analysis was done. Calf muscle spasticity and function were also measured.

RESULTS

Results showed significant differences between the two groups in the one-minute walking test (p = 0.023) and spasticity (after intervention [p = 0.022], after follow-up [p = 0.020]). Also, significant differences were detected between the two groups in the step width (p = 0.042), maximum hip abduction (p = 0.008), stance maximum dorsiflexion (p = 0.036) and mean pelvic tilt (p = 0.004) in the barefoot condition. Gait cycle time (p = 0.005), maximum hip abduction (p = 0.042), and cadence (p = 0.001) were different between groups in the braced condition. We couldn't find any significant within and between groups differences in knee kinematic parameters. The mean time of using vibration was 16.83 minutes per day.

CONCLUSIONS

The vibration-hinged AFO is feasible, safe, and acceptable for children with hemiplegic CP to be integrated into practice. Temporospatial and clinical parameters, especially spasticity, were improved. There were slight trends toward improvement in pelvic and knee kinematics. Vibration-HAFO is of benefit to ambulatory CP children with mild and moderate spasticity. It improved the walking capacity of the children.

Effects of prolonged vibration to the flexor carpi radialis muscle on intracortical excitability

Prolonged local vibration (LV) can induce neurophysiological adaptations thought to be related to long-term potentiation or depression. Yet, how changes in intracortical excitability may be involved remains to be further investigated as previous studies reported equivocal results. We therefore investigated the effects of 30 min of LV applied to the right flexor carpi radialis muscle (FCR) on both short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). SICI and ICF were measured through transcranial magnetic stimulation before and immediately after 30 min of FCR LV (vibration condition) or 30 min of rest (control condition). Measurements were performed during a low-intensity contraction (n = 17) or at rest (n = 7). No significant SICI nor ICF modulations were observed, whether measured during isometric contractions or at rest (p = 0.2). Yet, we observed an increase in inter-individual variability for post measurements after LV. In conclusion, while intracortical excitability was not significantly modulated after LV, increased inter-variability observed after LV may suggest the possibility of divergent responses to prolonged LV exposure.

Effects of whole-body vibration training on physical function, activities of daily living, and quality of life in patients with stroke: a systematic review and meta-analysis

Purpose: This systematic review and meta-analysis aimed to evaluate the efficacy of whole-body vibration training (WBVT) in patients with stroke, specifically focusing on its effects on physical function, activities of daily living (ADL), and quality of life (QOL). Additionally, potential moderators influencing WBVT outcomes were explored. Methods: We conducted a systematic search of PubMed, Embase, and Cochrane Library from inception to September 2022. Eligible studies were randomized controlled trials employing WBVT in patients with stroke. Two investigators independently extracted the data and calculated the standardized mean difference (SMD) using random-effect models. Results: Twenty-five studies involving 991 patients were included in this meta-analysis. WBVT demonstrated significant reductions in spasticity (SMD = -0.33, 95% CI = -0.61 to -0.06, p = 0.02), improvements in motor function (SMD = 0.39, 95% CI = 0.16 to 0.61, p < 0.01), and enhancements in balance function (SMD = 0.28, 95% CI = 0.09 to 0.47, p < 0.01) in patients with stroke. However, no significant effects were observed for gait (SMD = -0.23, 95% CI = -0.50 to 0.04, p = 0.10), ADL (SMD = -0.01, 95% CI = -0.46 to 0.44, p = 0.97), or QOL (SMD = 0.12, 95% CI = -0.30 to 0.53, p = 0.59). Subgroup analyses revealed that variable frequency vibration and side-alternating vibration exhibited significant efficacy in reducing spasticity and improving motor and balance functions, while fixed frequency vibration and vertical vibration did not yield significant therapeutic benefits in these domains. Conclusion: Our findings indicate that WBVT may serve as a viable adjunct therapy for stroke patients to alleviate spasticity and enhance motor and balance functions. Variable frequency and side-alternating vibration appear to be crucial factors influencing the therapeutic effects of WBVT on these dysfunctions. Nonetheless, WBVT did not show significant effects on gait, ADL, or QOL in stroke patients. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022384319).

Cortical activity associated with focal muscle vibration applied directly to the affected forearm flexor muscle in post-stroke patients: an fNIRS study

Objective

The purpose of this study was to utilize functional near-infrared spectroscopy (fNIRS) to identify changes in cortical activity caused by focal muscle vibration (FMV), which was directly administered to the affected forearm flexor muscles of hemiplegic stroke patients. Additionally, the study aimed to investigate the correlation between these changes and the clinical characteristics of the patients, thereby expanding the understanding of potential neurophysiological mechanisms linked to these effects.

Methods

Twenty-two stroke patients with right hemiplegia who were admitted to our ward for rehabilitation were selected for this study. The fNIRS data were collected from subjects using a block-design paradigm. Subsequently, the collected data were analyzed using the NirSpark software to determine the mean Oxyhemoglobin (Hbo) concentrations for each cortical region of interest (ROI) in the task and rest states for every subject. The stimulation task was FMV (frequency 60 Hz, amplitude 6 mm) directly applied to belly of the flexor carpi radialis muscle (FCR) on the affected side. Hbo was measured in six regions of interest (ROIs) in the cerebral cortex, which included the bilateral prefrontal cortex (PFC), sensorimotor cortex (SMC), and occipital cortex (OC). The clinical characteristics of the patients were assessed concurrently, including Lovett's 6-level muscle strength assessment, clinical muscle tone assessment, the upper extremity function items of the Fugl-Meyer Assessment (FMA-UE), Bruunstrom staging scale (BRS), and Modified Barthel index (MBI). Statistical analyses were conducted to determine the activation in the ROIs and to comprehend its correlation with the clinical characteristics of the patients.

Results

Statistical analysis revealed that, except for right OC, there were statistically significant differences between the mean Hbo in the task state and rest state for bilateral SMC, PFC, and left OC. A positive correlation was observed between the muscle strength of the affected wrist flexor group and the change values of Hbo (Hbo-CV), as well as the beta values in the left SMC, PFC, and OC. However, no statistical correlation was found between muscle strength and Hbo-CV or beta values in the right SMC, PFC, and OC. The BRS of the affected upper limb exhibited a positive correlation with the Hbo-CV or beta values in the left SMC and PFC. In contrast, no statistical correlation was observed in the right SMC, PFC, and bilateral OC. No significant correlation was found between the muscle tone of the affected wrist flexor group, FMA-UE, MBI, and Hbo-CV or beta values of cortical ROIs.

Conclusion

FMV-evoked sensory stimulation applied directly to the FCR belly on the paralyzed side activated additional brain cortices, including bilateral PFC and ipsilesional OC, along with bilateral SMC in stroke patients. However, the clinical characteristics of the patients were only correlated with the intensity of ipsilesional SMC and PFC activation. The results of this study provide neurophysiological theoretical support for the expanded clinical application of FMV.

Lesion-specific cortical activation following sensory stimulation in patients with subacute stroke

BACKGROUND

Sensory stimulation can play a fundamental role in the activation of the primary sensorimotor cortex (S1-M1), which can promote motor learning and M1 plasticity in stroke patients. However, studies have focused mainly on investigating the influence of brain lesion profiles on the activation patterns of S1-M1 during motor tasks instead of sensory tasks. Therefore, the objective of this study is to explore the lesion-specific activation patterns due to different brain lesion profiles and types during focal vibration (FV).

METHODS

In total 52 subacute stroke patients were recruited in this clinical experiment, including patients with basal ganglia hemorrhage/ischemia, brainstem ischemia, other subcortical ischemia, cortical ischemia, and mixed cortical-subcortical ischemia. Electroencephalograms (EEG) were recorded following a resting state lasting for 4 min and three sessions of FV. FV was applied over the muscle belly of the affected limb's biceps for 3 min each session. Beta motor-related EEG power desynchronization overlying S1-M1 was used to indicate the activation of S1-M1, while the laterality coefficient (LC) of the activation of S1-M1 was used to assess the interhemispheric asymmetry of brain activation.

RESULTS

(1) Regarding brain lesion profiles, FV could lead to the significant activation of bilateral S1-M1 in patients with basal ganglia ischemia and other subcortical ischemia. The activation of ipsilesional S1-M1 in patients with brainstem ischemia was higher than that in patients with cortical ischemia. No activation of S1-M1 was observed in patients with lesions involving cortical regions. (2) Regarding brain lesion types, FV could induce the activation of bilateral S1-M1 in patients with basal ganglia hemorrhage, which was significantly higher than that in patients with basal ganglia ischemia. Additionally, LC showed no significant correlation with the modified Barthel index (MBI) in all patients, but a positive correlation with MBI in patients with basal ganglia lesions.

CONCLUSIONS

These results reveal that sensory stimulation can induce lesion-specific activation patterns of S1-M1. This indicates FV could be applied in a personalized manner based on the lesion-specific activation of S1-M1 in stroke patients with different lesion profiles and types. Our study may contribute to a better understanding of the underlying mechanisms of cortical reorganization.

Enhanced Motor Imagery Decoding by Calibration Model-Assisted With Tactile ERD

OBJECTIVE

In this study, we propose a tactile-assisted calibration method for a motor imagery (MI) based Brain-Computer Interface (BCI) system.

METHOD

In the proposed calibration, tactile stimulation was applied to the hand wrist to assist the subjects in the MI task, which is named SA-MI task. Then, classifier training in the SA-MI Calibration was performed using the SA-MI data, while the Conventional Calibration employed the MI data. After the classifiers were trained, the performance was evaluated on a common MI dataset.

RESULTS

Our study demonstrated that the SA-MI Calibration significantly improved the performance as compared with the Conventional Calibration, with a decoding accuracy of (78.3% vs. 71.3%). Moreover, the average calibration time could be reduced by 40%. This benefit of the SA-MI Calibration effect was further validated by an independent control group, which showed no improvement when tactile stimulation was not applied during the calibration phase. Further analysis showed that when compared with MI, greater motor-related cortical activation and higher R 2 value in the alpha-beta frequency band were induced in SA-MI.

CONCLUSION

Indeed, the SA-MI Calibration could significantly improve the performance and reduce the calibration time as compared with the Conventional Calibration.

SIGNIFICANCE

The proposed tactile stimulation-assisted MI Calibration method holds great potential for a faster and more accurate system setup at the beginning of BCI usage.

Effectiveness of Focal Muscle Vibration in the Recovery of Neuromotor Hypofunction: A Systematic Review

Adequate physical recovery after trauma, injury, disease, a long period of hypomobility, or simply ageing is a difficult goal because rehabilitation protocols are long-lasting and often cannot ensure complete motor recovery. Therefore, the optimisation of rehabilitation procedures is an important target to be achieved. The possibility of restoring motor functions by acting on proprioceptive signals by unspecific repetitive muscle vibration, focally applied on single muscles (RFV), instead of only training muscle function, is a new perspective, as suggested by the effects on the motor performance evidenced by healthy persons. The focal muscle vibration consists of micro-stretching-shortening sequences applied to individual muscles. By repeating such stimulation, an immediate and persistent increase in motility can be attained. This review aims to show whether this proprioceptive stimulation is useful for optimising the rehabilitative process in the presence of poor motor function. Papers reporting RFV effects have evidenced that the motor deficits can be counteracted by focal vibration leading to an early and quick complete recovery. The RFV efficacy has been observed in various clinical conditions. The motor improvements were immediate and obtained without loading the joints. The review suggests that these protocols can be considered a powerful new advantage to enhance traditional rehabilitation and achieve a more complete motor recovery.

Enhanced lower-limb motor imagery by kinesthetic illusion

Brain-computer interface (BCI) based on lower-limb motor imagery (LMI) enables hemiplegic patients to stand and walk independently. However, LMI ability is usually poor for BCI-illiterate (e.g., some stroke patients), limiting BCI performance. This study proposed a novel LMI-BCI paradigm with kinesthetic illusion(KI) induced by vibratory stimulation on Achilles tendon to enhance LMI ability. Sixteen healthy subjects were recruited to carry out two research contents: (1) To verify the feasibility of induced KI by vibrating Achilles tendon and analyze the EEG features produced by KI, research 1 compared the subjective feeling and brain activity of participants during rest task with and without vibratory stimulation (V-rest, rest). (2) Research 2 compared the LMI-BCI performance with and without KI (KI-LMI, no-LMI) to explore whether KI enhances LMI ability. The analysis methods of both experiments included classification accuracy (V-rest vs. rest, no-LMI vs. rest, KI-LMI vs. rest, KI-LMI vs. V-rest), time-domain features, oral questionnaire, statistic analysis and brain functional connectivity analysis. Research 1 verified that induced KI by vibrating Achilles tendon might be feasible, and provided a theoretical basis for applying KI to LMI-BCI paradigm, evidenced by oral questionnaire (Q1) and the independent effect of vibratory stimulation during rest task. The results of research 2 that KI enhanced mesial cortex activation and induced more intensive EEG features, evidenced by ERD power, topographical distribution, oral questionnaire (Q2 and Q3), and brain functional connectivity map. Additionally, the KI increased the offline accuracy of no-LMI/rest task by 6.88 to 82.19% (p < 0.001). The simulated online accuracy was also improved for most subjects (average accuracy for all subjects: 77.23% > 75.31%, and average F1_score for all subjects: 76.4% > 74.3%). The LMI-BCI paradigm of this study provides a novel approach to enhance LMI ability and accelerates the practical applications of the LMI-BCI system.

Can vibrotactile stimulation and tDCS help inefficient BCI users?

Brain-computer interface (BCI) has helped people by allowing them to control a computer or machine through brain activity without actual body movement. Despite this advantage, BCI cannot be used widely because some people cannot achieve controllable performance. To solve this problem, researchers have proposed stimulation methods to modulate relevant brain activity to improve BCI performance. However, multiple studies have reported mixed results following stimulation, and the comparative study of different stimulation modalities has been overlooked. Accordingly, this study was designed to compare vibrotactile stimulation and transcranial direct current stimulation's (tDCS) effects on brain activity modulation and motor imagery BCI performance among inefficient BCI users. We recruited 44 subjects and divided them into sham, vibrotactile stimulation, and tDCS groups, and low performers were selected from each stimulation group. We found that the latter's BCI performance in the vibrotactile stimulation group increased significantly by 9.13% (p < 0.01), and while the tDCS group subjects' performance increased by 5.13%, it was not significant. In contrast, sham group subjects showed no increased performance. In addition to BCI performance, pre-stimulus alpha band power and the phase locking values (PLVs) averaged over sensory motor areas showed significant increases in low performers following stimulation in the vibrotactile stimulation and tDCS groups, while sham stimulation group subjects and high performers showed no significant stimulation effects across all groups. Our findings suggest that stimulation effects may differ depending upon BCI efficiency, and inefficient BCI users have greater plasticity than efficient BCI users.

Investigating the Effects of a Focal Muscle Vibration Protocol on Sensorimotor Integration in Healthy Subjects

Background: The ability to perceive two tactile stimuli as asynchronous can be measured using the somatosensory temporal discrimination threshold (STDT). In healthy humans, the execution of a voluntary movement determines an increase in STDT values, while the integration of STDT and movement execution is abnormal in patients with basal ganglia disorders. Sensorimotor integration can be modulated using focal muscle vibration (fMV), a neurophysiological approach that selectively activates proprioceptive afferents from the vibrated muscle. Method: In this study, we investigated whether fMV was able to modulate STDT or STDT-movement integration in healthy subjects by measuring them before, during and after fMV applied over the first dorsalis interosseous, abductor pollicis brevis and flexor radialis carpi muscles. Results: The results showed that fMV modulated STDT-movement integration only when applied over the first dorsalis interosseous, namely, the muscle performing the motor task involved in STDT-movement integration. These changes occurred during and up to 10 min after fMV. Differently, fMV did not influence STDT at rest. We suggest that that fMV interferes with the STDT-movement task processing, possibly disrupting the physiological processing of sensory information. Conclusions: This study showed that FMV is able to modulate STDT-movement integration when applied over the muscle involved in the motor task. This result provides further information on the mechanisms underlying fMV, and has potential future implications in basal ganglia disorders characterized by altered sensorimotor integration.

Proprioceptive Focal Stimulation (Equistasi®) for gait and postural balance rehabilitation in patients with Parkinson's disease: A systematic review

Gait and postural deficits are the most common impairments in patients with Parkinson's Disease (PD). These impairments often reduce patients' quality of life. Equistasi^® is a wearable proprioceptive stabilizer that converts body thermic energy into mechanical vibration. No systematic reviews have been published investigating the influences of Equistasi^® on gait and postural control in patients with PD. This review aimed to examine the effects of proprioceptive focal stimulation (Equistasi^®) on gait deficits and postural instability in patients with PD. PubMed, Scopus, PEDro, REHABDATA, web of science, CHAINAL, EMBASE, and MEDLINE were searched from inception to July 2021. The methodological quality of the selected studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. Five studies met the eligibility criteria. The scores on the PEDro scale ranged from 3 to 8, with a median score of 8. The results showed evidence for the benefits of the proprioceptive focal stimulation (Equistasi^®) on gait and postural stability in individuals with PD. Proprioceptive focal stimulation (Equistasi^®) appears to be safe and well-tolerated in patients with PD. Proprioceptive focal stimulation (Equistasi^®) may improve gait ability and postural stability in patients with PD. Further high-quality studies with long-term follow-ups are strongly needed to clarify the long-term effects of proprioceptive focal stimulation (Equistasi^®) in patients with PD.

Effect of upper limb focal muscle vibration on cortical activity: A systematic review with a focus on primary motor cortex

This systematic review aimed to investigate the effects of upper extremity focal muscle vibration (FMV) on cortical activity. A systematic literature search was conducted for articles published in English in the SCOPUS, PEDro, PUBMED, REHABDATA, MEDLINE, and Web of Science databases. Eighteen studies (6 controlled and 12 experimental studies) were included in the systematic review. A total of 264 individuals (20 to 68 years) participated in the studies. The outcome of this review showed that FMV might have contradictory effects on cortical areas: (a) Reduction of cortical activity in the primary motor cortex (M1) and somatosensory cortex (S1), (b) no changes in the cortical activity of M1, and (c) increased cortical activity of M1 and S1. These effects may depend on different factors such as frequency and amplitude of FMV, vibration exposure time, and muscle status. However, no single factor can definitely be accounted for the variance.

Estimation of Gross Motor Functions in Children with Cerebral Palsy Using Zebris FDM-T Treadmill

A standardized observational instrument designed to measure change in gross motor function over time in children with cerebral palsy is the Gross Motor Function Measure (GMFM). The process of evaluating a value for the GMFM index can be time consuming. It typically takes 45 to 60 min for the patient to complete all tasks, sometimes in two or more sessions. The diagnostic procedure requires trained and specialized therapists. The paper presents the estimation of the GMFM measure for patients with cerebral palsy based on the results of the Zebris FDM-T treadmill. For this purpose, the regression analysis was used. Estimations based on the Generalized Linear Regression were assessed using different error metrics. The results obtained showed that the GMFM score can be estimated with acceptable accuracy. Because the Zebris FDM-T is a widely used device in gait rehabilitation, our method has the potential to be widely adopted for objective diagnostics of children with cerebral palsy.

Correlations between Electro-Diagnostic Findings, the Severity of Initial Infection, and the Rehabilitation Outcomes among COVID-19 Patients

Patients with Coronavirus-2019 (COVID-19) manifest many neuromuscular complications. We evaluated the correlations between electromyography and nerve conduction measurements among COVID-19 patients and the severity of the initial infection, as well as the rehabilitation outcomes, and searched for the factors which best predict the rehabilitation outcomes. A total of 19 COVID-19 patients (16 men; mean ± SD age 59.1 ± 10.4), with WHO clinical progression scale of 6.8 ± 2.3, received rehabilitation for 3.9 ± 2.5 months. The Functional Independence Measure (FIM), the 10 m walk test, the 6 minute walk test, and grip force were collected before and after the rehabilitation period. Motor Nerve Conduction (MNC), Sensory Nerve Conduction (SNC) and electromyographic abnormalities were measured. All of the MNC measures of the median nerve correlated with the WHO clinical progression scale and duration of acute hospitalization. The MNC and SNC measures correlated with the rehabilitation duration and with FIM at discharge. The MNC distal latency of the median and the peroneal nerves and the MNC velocity of the median and tibial nerves predicted 91.6% of the variance of the motor FIM at discharge. We conclude that nerve conduction measurements, especially in COVID-19 patients with severe illness, are important in order to predict prognosis and rehabilitation outcomes.

Use of a Portable Inertial Measurement Unit as an Evaluation Method for Supraspinatus Muscle: Proposed Normative Values

Treatment protocols do not specify an appropriate weight for rehabilitating the shoulder joint. The purpose of this study was to establish normative values for the shoulder abduction range of motion and recommended weights to be used in the rehabilitation process after injury to the supraspinatus muscle. Fifty-eight volunteers were assessed using the DyCare system. A test was conducted by lifting the arm to a 90° angle and having the participants lift different weights. The range of motion was similar for both sexes, suggesting that sex had no influence on this variable. Regarding the use of weights, men did not show as much stability in their movement execution, with a high dispersion seen in values between zero and three kilograms of weight, reaching a maximum weight of six kilograms. However, women showed good joint stability from the beginning of the test, with values that remained constant as weight increased up to a maximum of five kilograms. In conclusion, no major differences were observed in supraspinatus muscle injury recovery according to sex. However, differences were observed in the amount of weight that was necessary and appropriate to allow the participants to recover their muscular strength and avoid relapses.

A P300 Brain-Computer Interface Paradigm Based on Electric and Vibration Simple Command Tactile Stimulation

This paper proposed a novel tactile-stimuli P300 paradigm for Brain-Computer Interface (BCI), which potentially targeted at people with less learning ability or difficulty in maintaining attention. The new paradigm using only two types of stimuli was designed, and different targets were distinguished by frequency and spatial information. The classification algorithm was developed by introducing filters for frequency bands selection and conducting optimization with common spatial pattern (CSP) on the tactile evoked EEG signals. It features a combination of spatial and frequency information, with the spatial information distinguishing the sites of stimuli and frequency information identifying target stimuli and disturbances. We investigated both electrical stimuli and vibration stimuli, in which only one target site was stimulated in each block. The results demonstrated an average accuracy of 94.88% for electrical stimuli and 95.21% for vibration stimuli, respectively.

The intervention of mechanical tactile stimulation modulates somatosensory evoked magnetic fields and cortical oscillations

The different cortical activity evoked by a mechanical tactile stimulus depends on tactile stimulus patterns, which demonstrates that simple stimuli (i.e., global synchronous stimulation the stimulus area) activate the primary somatosensory cortex alone, whereas complex stimuli (i.e., stimulation while moving in the stimulus area) activate not only the primary somatosensory cortex but also the primary motor area. Here, we investigated whether the effects of a repetitive mechanical tactile stimulation (MS) on somatosensory evoked magnetic fields (SEFs) and cortical oscillations depend on MS patterns. This single-blinded study included 15 healthy participants. Two types interventions of MS lasting 20 min were used: a repetitive global tactile stimulation (RGS) was used to stimulate the finger by using 24 pins installed on a finger pad, whereas a sequential stepwise displacement tactile stimulation (SSDS) was used to stimulate the finger by moving a row of six pins between the left and right sides on the finger pad. Each parameter was measured pre- and post-intervention. The P50m amplitude of the SEF was increased by RGS and decreased by SSDS. The modulation of P50m was correlated with its amplitude before RGS and with the modulation of beta band oscillation at the resting state after SSDS. This study showed that the effects of a 20-min MS on SEFs and cortical oscillations depend on mechanical tactile stimulus patterns. Moreover, our results offer potential for the modulation of tactile functions and selection of stimulation patterns according to cortical states.

Wearable Focal Muscle Vibration on Pain, Balance, Mobility, and Sensation in Individuals with Diabetic Peripheral Neuropathy: A Pilot Study

People with diabetic peripheral neuropathy (DPN) experience a lower quality of life caused by associated pain, loss of sensation and mobility impairment. Current standard care for DPN is limited and lacking. This study explores the benefits of 4-week, in-home wearable focal muscle vibration (FMV) therapy on pain, balance, mobility, and sensation in people with DPN. Participants were randomized into three groups and received different FMV intensities. FMV was applied using a modified Myovolt^TM wearable device to the tibialis anterior, distal quadriceps, and gastrocnemius/soleus muscles on both lower limbs for three days a week over four weeks. The outcomes included pain, balance, mobility, sensation, device usage log, feedback survey, and a semi-structured interview. In all, 23 participants completed the study. The results showed significant improvement in average pain (Pre: 4.00 ± 2.29; Post: 3.18 ± 2.26; p = 0.007), pain interference with walking ability (Pre: 4.14 ± 3.20; Post: 3.09 ± 1.976; p = 0.03), and standard and cognitive Timed Up-and-Go scores (Pre: 13.75 ± 5.34; Post: 12.65 ± 5.25; p = 0.04; Pre: 15.12 ± 6.60; Post: 12.71 ± 5.57; p = 0.003, respectively); the overall pain improvement was trending towards significance (Pre: 3.48 ± 2.56; Post: 2.87 ± 1.85; p = 0.051). Balance and sensations improved but not significantly. There was a trend towards significance (p = 0.088), correlation (r = 0.382) between changes in balance and baseline pain. The participants were highly satisfied with wearable FMV and were 100% compliant. FMV therapy was associated with improved pain, mobility, and sensation. Further study with a larger sample and better outcome measures are warranted.

Motor Recovery After Stroke: From a Vespa Scooter Ride Over the Roman Sampietrini to Focal Muscle Vibration (fMV) Treatment. A 99mTc-HMPAO SPECT and Neurophysiological Case Study

Focal repetitive muscle vibration (fMV) is a safe and well-tolerated non-invasive brain and peripheral stimulation (NIBS) technique, easy to perform at the bedside, and able to promote the post-stroke motor recovery through conditioning the stroke-related dysfunctional structures and pathways. Here we describe the concurrent cortical and spinal plasticity induced by fMV in a chronic stroke survivor, as assessed with 99mTc-HMPAO SPECT, peripheral nerve stimulation, and gait analysis. A 72-years-old patient was referred to our stroke clinic for a right leg hemiparesis and spasticity resulting from a previous (4 years before) hemorrhagic stroke. He reported a subjective improvement of his right leg's spasticity and dysesthesia that occurred after a30-min ride on a Vespa scooter as a passenger over the Roman Sampietrini (i.e., cubic-shaped cobblestones). Taking into account both the patient's anecdote and the current guidelines that recommend fMV for the treatment of post-stroke spasticity, we then decided to start fMV treatment. 12 fMV sessions (frequency 100 Hz; amplitude range 0.2–0.5 mm, three 10-min daily sessions per week for 4 consecutive weeks) were applied over the quadriceps femoris, triceps surae, and hamstring muscles through a specific commercial device (Cro®System, NEMOCOsrl). A standardized clinical and instrumental evaluation was performed before (T0) the first fMV session and after (T1) the last one. After fMV treatment, we observed a clinically relevant motor and functional improvement, as assessed by comparing the post-treatment changes in the score of the Fugl-Meyer assessment, the Motricity Index score, the gait analysis, and the Ashworth modified scale, with the respective minimal detectable change at the 95% confidence level (MDC₉₅). Data from SPECT and peripheral nerve stimulation supported the evidence of a concurrent brain and spinal plasticity promoted by fMV treatment trough activity-dependent changes in cortical perfusion and motoneuron excitability, respectively. In conclusion, the substrate of post-stroke motor recovery induced by fMV involves a concurrently acting multisite plasticity (i.e., cortical and spinal plasticity). In our patient, operant conditioning of both cortical perfusion and motoneuron excitability throughout a month of fMV treatment was related to a clinically relevant improvement in his strength, step symmetry (with reduced limping), and spasticity.

Localized muscle vibration in the treatment of motor impairment and spasticity in post-stroke patients: a systematic review

INTRODUCTION

During the last decades, many studies have been carried out to understand the possible positive effects of vibration therapy in post-stroke rehabilitation. In particular, the use of localized muscle vibration (LMV) seems to have promising results. The aim of this systematic review was to describe the use of LMV in post-stroke patients to improve motor recovery, reducing spasticity and disability in both upper and lower limb.

EVIDENCE ACQUISITION

A search was conducted on PubMed, Scopus, Pedro and REHABDATA electronic database. Only randomized controlled trials have been included, excluding no-localized vibratory treatments and other pathological conditions. Fourteen studies met the inclusion criteria and were included in this review.

EVIDENCE SYNTHESIS

Collectively, the studies involved 425 stroke patients. Most studies included chronic stroke patients (ten) and treated only the upper limb (eleven). There is evidence that LMV therapy is effective in reducing spasticity and improving motor recovery, especially when associated with conventional physical therapy.

CONCLUSIONS

LMV may be a feasible and safe tool to be integrated into traditional and conventional neurorehabilitation programs for post-stroke patients to reduce spasticity. Analysis of the available clinical trials do not allow us to indicate vibration therapy as effective in functional motor recovery, despite some studies showed encouraging results. Further studies, with larger size of homogeneous patients and with a shared methodology are needed to produce more reliable data, especially on the lower limb.

Sensory inflow manipulation induces learning-like phenomena in motor behavior

PURPOSE

Perceptual and goal-directed behaviors may be improved by repetitive sensory stimulations without practice-based training. Focal muscle vibration (f-MV) modulating the spatiotemporal properties of proprioceptive inflow is well-suited to investigate the effectiveness of sensory stimulation in influencing motor outcomes. Thus, in this study, we verified whether optimized f-MV stimulation patterns might affect motor control of upper limb movements.

METHODS

To answer this question, we vibrated the slightly tonically contracted anterior deltoid (AD), posterior deltoid (PD), and pectoralis major muscles in different combinations in forty healthy subjects at a frequency of 100 Hz for 10 min in single or repetitive administrations. We evaluated the vibration effect immediately after f-MV application on upper limb targeted movements tasks, and one week later. We assessed target accuracy, movement mean and peak speed, and normalized Jerk using a 3D optoelectronic motion capture system. Besides, we evaluated AD and PD activity during the tasks using wireless electromyography.

RESULTS

We found that f-MV may induce increases (p < 0.05) in movement accuracy, mean speed and smoothness, and changes (p < 0.05) in the electromyographic activity. The main effects of f-MV occurred overtime after repetitive vibration of the AD and PD muscles.

CONCLUSION

Thus, in healthy subjects, optimized f-MV stimulation patterns might over time affect the motor control of the upper limb movement. This finding implies that f-MV may improve the individual's ability to produce expected motor outcomes and suggests that it may be used to boost motor skills and learning during training and to support functional recovery in rehabilitation.

Effects of focal vibration on power and work in multiple wingate tests

The aim of the study was to assess the effects of a specific protocol, based on a focal muscle vibration, on mechanical parameters in an exercise composed of five repeated bouts of sprint interval tests (Wingate Anaerobic Tests, 10 seconds duration). Twenty-eight young male healthy subjects were randomized to two groups (VIB and CTRL). Peak power (PP), average peak between bouts (aP) and total exercise work (TW) were measured. In both groups, three different exercise sessions were carried out, interspersed by seven days: T0, T1 and T2. Between the baseline (T0) and T1, in the VIB group the intervention was administered on three successive days on quadriceps muscles, whereas a placebo administration was carried out in the CTRL group at the same time. At T1 (30 minutes after intervention) and T2 (7 days after) CTRL did not show any significant change, whereas VIB showed significant increases in PP (11.4%–9.3%), aP (6.6%–6.9%) and TW (5.7%–7.9%) with respect to T0. The results could be explained by an ameliorative agonist-antagonist balance, and this hypothesis is coherent with the literature. On the basis of the present findings, the investigated intervention might be usefully adopted to increase muscular power and endurance.

Noninvasive Brain Stimulation and Noninvasive Peripheral Stimulation for Neglect Syndrome Following Acquired Brain Injury

OBJECTIVE

Hemispatial neglect is a frequent condition usually following nondominant hemispheric brain injury. It strongly affects rehabilitation strategies and everyday life activities. It is associated with behavioral and cognitive disability with a strong impact on patient's life.

METHODS

We reviewed the published literature on the use of noninvasive brain stimulation, including repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), and of noninvasive peripheral muscle stimulation, as therapeutic strategies for rehabilitation of neglect after acquired brain injury, such as in stroke or in traumatic injuries. The studies were grouped as controlled or uncontrolled studies in each stimulation techniques.

RESULTS

Thirty-four studies were identified and 16 on rTMS, 10 on tDCS, and 8 on vibration. All studies were conducted in adult patients who suffered a stroke, except for one that was conducted in a patient suffering traumatic acquired brain injury and another that was conducted in a patient with brain tumor. In spite of significant variability in treatment protocols, patients' features and assessment of neglect, improvement was reported in almost all studies with no side-effects.

CONCLUSIONS

Noninvasive brain stimulation and neuromuscular vibration are promising therapeutic neuromodulatory approaches for neglect. Further randomized-controlled studies are needed to corroborate their effectiveness as separate and combined techniques.

Influence of focal vibration over Achilles tendon on the activation of sensorimotor cortex in healthy subjects and subacute stroke patients

The modulation of cerebral activity could induce plastic changes in the cerebral cortex and contribute to motor rehabilitation. Focal vibration over lower-extremity muscles has therapeutic effects on the impaired motor function for stroke patients, but the modulatory effects of focal vibration on brain activity are less known. To explore this problem, this experiment was designed and conducted, in which focal vibration (75 Hz) was applied over the right Achilles tendon of 14 healthy subjects and the affected Achilles tendon of seven subacute stroke patients. Electroencephalography was recorded in the following phases: resting-state and three focal vibration sessions. Electroencephalographical analysis showed a significantly desynchronized power of contralateral primary sensorimotor cortex (S1-M1) in beta1 band (13-18 Hz) following all focal vibration sessions occurred in healthy subjects compared to resting-state, whereas a significantly desynchronized power of bilateral S1-M1 in the beta1 and beta2 band (18-21 Hz) was observed in stroke patients compared to resting-state. Besides, event-related power desynchronization of bilateral S1-M1 in stroke patients was significantly lower than healthy subjects in the beta2 and beta3 band (21-30 Hz) during focal vibration sessions. These results demonstrated that focal vibration over Achilles tendon could activate bilateral S1-M1 in stroke patients, which was different in healthy subjects. These indications contribute to a better understanding of the underlying mechanism of focal vibration on stroke rehabilitation.

Study of the activation in sensorimotor cortex and topological properties of functional brain network following focal vibration on healthy subjects and subacute stroke patients: An EEG study

Modulation on cerebral cortex and cerebral networks can induce reorganization of the brain, which contributes to rehabilitation. Previous studies have proved that focal vibration (FV) on limb muscles can modulate the activities of sensorimotor cortex in healthy subjects (HS). The objective of this paper is to study the modulatory effects of FV on the sensorimotor cortex and cerebral network in HS and subacute stroke patients (SP). An experiment was designed and conducted, during which FV of 75 Hz was applied over biceps muscle of right limb of 10 HS and 10 SP with right hemiplegia. Electroencephalography (EEG) was recorded in the following phases: before FV, control condition and three sessions of FV. EEG analysis showed a significant decrease in motor-related power desynchronization (MRPD) of contralesional primary sensorimotor cortex (contralesional S1-M1) in the beta2 band (18-21 Hz) for SP during FV sessions, as well as in MRPD of bilateral S1-M1 in the beta1 (13-18 Hz) and the beta2 band for HS. Moreover, MRPD of contralesional S1-M1 was significantly lower than MRPD of ipsilesional S1-M1 during FV. Besides, a significant increase of global efficiency (E) and decrease of characteristic path length (L) were identified in the beta1 band for SP, whereas a significant increase of L was identified for HS. The results indicated that FV could enhance the excitability of contralesional S1-M1 and alter topological properties of functional brain network for SP, which was different in HS. This indication can contribute to understanding the modulatory effects of FV on cerebral cortex and cerebral network.

Feasibility of Whole Body Vibration Therapy in Individuals with Dystonic or Spastic Dystonic Cerebral Palsy: A Pilot Study

Objective

To examine the feasibility and practicality of whole body vibration therapy for individuals with dystonic or spastic dystonic cerebral palsy.

Design

Pilot study.

Subjects

Children and adults with dystonic or spastic dystonic cerebral palsy.

Methods

Study participants received total body vibration therapy when standing still on a vibration platform for 3 bouts, duration 3-min, of vibration (20 Hz, 2 mm amplitude), 4 days per week for 4 weeks in addition to their usual therapy. All participants were assessed at baseline and completion of the study using the Gross Motor Function Measure Item Set, Timed Up and Go test, Barry-Albright Dystonia Scale, Edinburgh Visual Gait Score, and Pediatric Evaluation of Disability Inventory.

Results

Ten participants (mean age 18.60 years (standard deviation (SD) 14.68); 9 males, Gross Motor Function Classification System level II-IV) completed the study with more than 90% attendance rate. All participants tolerated the protocol with no adverse events.

Conclusion

The vibration treatment protocol was feasible and safe for all participants. With no significant differences found in all the outcome measures, future studies with more rigorous study designs are required before this intervention is recommended for this population group.

Progressive Training for Motor Imagery Brain-Computer Interfaces Using Gamification and Virtual Reality Embodiment

This paper presents a gamified motor imagery brain-computer interface (MI-BCI) training in immersive virtual reality. The aim of the proposed training method is to increase engagement, attention, and motivation in co-adaptive event-driven MI-BCI training. This was achieved using gamification, progressive increase of the training pace, and virtual reality design reinforcing body ownership transfer (embodiment) into the avatar. From the 20 healthy participants performing 6 runs of 2-class MI-BCI training (left/right hand), 19 were trained for a basic level of MI-BCI operation, with average peak accuracy in the session = 75.84%. This confirms the proposed training method succeeded in improvement of the MI-BCI skills; moreover, participants were leaving the session in high positive affect. Although the performance was not directly correlated to the degree of embodiment, subjective magnitude of the body ownership transfer illusion correlated with the ability to modulate the sensorimotor rhythm.

Effects of Focal Vibration over Upper Limb Muscles on the Activation of Sensorimotor Cortex Network: An EEG Study

Studying the therapeutic effects of focal vibration (FV) in neurorehabilitation is the focus of current research. However, it is still not fully understood how FV on upper limb muscles affects the sensorimotor cortex in healthy subjects. To explore this problem, this experiment was designed and conducted, in which FV was applied to the muscle belly of biceps brachii in the left arm. During the experiment, electroencephalography (EEG) was recorded in the following three phases: before FV, during FV, and two minutes after FV. During FV, a significant lower relative power at C3 and C4 electrodes and a significant higher connection strength between five channel pairs (Cz-FC1, Cz-C3, Cz-CP6, C4-FC6, and FC6-CP2) in the alpha band were observed compared to those before FV. After FV, the relative power at C4 in the beta band showed a significant increase compared to its value before FV. The changes of the relative power at C4 in the alpha band had a negative correlation with the relative power of the beta band during FV and with that after FV. The results showed that FV on upper limb muscles could activate the bilateral primary somatosensory cortex and strengthen functional connectivity of the ipsilateral central area (FC1, C3, and Cz) and contralateral central area (CP2, Cz, C4, FC6, and CP6). These results contribute to understanding the effect of FV over upper limb muscles on the brain cortical network.

Use of whole body vibration therapy in individuals with moderate severity of cerebral palsy- a feasibility study

Background

This pilot study was to examine the feasibility and tolerance of whole body vibration therapy (WBVT) for children and adults with moderate severity of cerebral palsy (CP) being graded as levels III or IV on the Gross Motor Function Classification Scale (GMFCS).

Methods

Study participants received the additional WBVT when standing still on the vibration platform for three 3-min bouts of vibration (20 Hz, 2 mm amplitude), 4 days per week for 4 weeks. In addition to questions relating to feasibility and participants’ opinions, assessment at baseline and completion of the intervention included the Gross Motor Function Measure-66 Item Set (GMFM-66 IS), 2-min walk test (2MWT), Timed Up and Go test (TUG) and Pediatric Evaluation of Disability Inventory (PEDI). Wilcoxon Signed Ranks test was used to compare the results.

Results

Fourteen participants (mean age = 25.25 years SD 3.71; 9 males, 64%; GMFCS level III n = 13, 92%) were recruited and completed the study. The attendance rate was over 90% with no adverse events. All participants tolerated the protocol which was satisfactorily delivered in a clinical setting.

Conclusions

The present WBVT protocol was feasible, safe and well-tolerated by the participants with moderate severity of CP, justifying future studies with larger samples and more rigorous study design.

Trial registration

The present study has been registered under the ClinicalTrials.gov (NCT03375736) and the date of registration commenced on 18 December 2017.

Tactile Stimulation Improves Sensorimotor Rhythm-based BCI Performance in Stroke Patients

OBJECTIVE

BCI decoding accuracy plays a crucial role in practical applications. With accurate feedback, BCI-based therapy determines beneficial neural plasticity in stroke patients. In this study, we aimed at improving sensorimotor rhythm (SMR)-based BCI performance by integrating motor tasks with tactile stimulation.

METHODS

Eleven stroke patients were recruited for three experimental conditions, i.e., motor attempt (MA) condition, tactile stimulation (TS) condition, and tactile stimulation-assisted motor attempt (TS-MA) condition. Tactile stimulation was delivered to the paretic hand wrist during both task and idle states using a DC vibrator.

RESULTS

We observed that the TS-MA condition achieved greater motor-related cortical activation (MRCA) in alpha-beta band when compared with both TS and MA conditions. Consequently, online BCI decoding accuracies between task and idle states were significantly improved from 74.5% in the MA condition to 85.1% in the TS-MA condition (p < 0.001), whereas the accuracy in the TS condition was 54.6% (approaching to the chance level of 50%).

CONCLUSION

This finding demonstrates that sensory afferent from peripheral nerves benefits the neural process of sensorimotor cortex in stroke patients. With appropriate sensory stimulation, MRCA is enhanced and corresponding brain patterns are more discriminative.

SIGNIFICANCE

This novel SMR-BCI paradigm shows great promise to facilitate the practical application of BCI-based stroke rehabilitation.

Non-invasive Focal Mechanical Vibrations Delivered by Wearable Devices: An Open-Label Pilot Study in Childhood Ataxia

Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest to improve motor control in different neurological diseases. Nanotechnology allowed the creation of wearable devices transforming thermal variations into mechanical energy with focal vibrations. This kind of wearable stimulators (WS) has produced encouraging preliminary results when used in the treatment of movement disorders and ataxia in adults. In this open label pilot study we first evaluated the feasibility, safety and effectiveness of NIFMV by WS in a cohort of 10 patients with childhood ataxia, a phenomenological category including different conditions still lacking of effective symptomatic therapies. Through the assessment of both clinical rating scales and spatio-temporal gait parameters via standardized gait analysis, we observed that a 4 weeks long treatment with WS Equistasi® was safe and provided significantly different effects in stride features of patients with slow/non-progressive cerebellar ataxia and Friedreich's Ataxia. Although limited by the sample size, the absence of a placebo-controlled group, the poor compliance of enrolled population to the original experimental design and the partial accuracy of outcome measures in pediatric subjects, we suggest that NIFMV by WS could support locomotion of patients with childhood slow/non-progressive cerebellar ataxia with preserved sensory system and no signs of peripheral neuropathy. Future studies are definitely necessary to confirm these preliminary results and define criteria for successful NIFMV-based treatment