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

Impact of Focal Muscle Vibration on Flaccid Upper Limb Motor Paralysis following Acute Brain Disease: A Case Study

Focal muscle vibration (FMV) is increasingly being recognized as a rehabilitative therapy for enhancing motor function in central nervous system (CNS) diseases, particularly in patients with fine motor control deficits stemming from CNS damage. Brain lesions from these diseases disrupt the motor networks, necessitating novel rehabilitation strategies. By applying vibrations to muscles, FMV stimulates sensory fibers to induce cortical activity and kinesthetic illusions. While initial studies have highlighted FMV's role in reducing spasticity, recent evidence points to its potential in treating motor paralysis. However, prior research has been limited by the lack of acute-phase studies and a focus on patients with minimal muscle contraction capability. This report aimed to explore FMV's efficacy on upper limb motor function in patients with flaccid motor paralysis immediately after acute CNS diseases. We report the case of a septuagenarian male with a brain abscess in the right parietal lobe, leading to flaccid motor paralysis. Rehabilitation included 28 sessions of occupational and physical therapy that incorporated FMV. Significant improvements were observed in upper extremity function, with moderate to very large effect sizes, while lower limb function showed lesser improvement without adverse effects. This case suggests the utility of FMV in enhancing upper-limb motor function after acute CNS injuries, potentially serving as a supplementary therapy for spontaneous recovery. This report contributes to emerging evidence on FMV's benefits in acute flaccid motor paralysis, expanding the documented therapeutic scope.

Focal muscle vibrations improve swallowing in persistent dysphagia after traumatic brain injury: A case report

Dysphagia is a common complication following traumatic brain injury (TBI), and it is related to an increased risk of malnutrition, pneumonia, and poor prognosis. In this article, we present a case of TBI with persistent dysphagia treated with focal muscle vibration. A 100 Hz and 50 Hz vibratory stimuli were applied over the suprahyoid muscles and tongue (30 min twice a day; five days a week; for a total of four weeks) in addition to the conventional therapy to quickly recover swallowing and avoid the possibility of permanent deficits. In conclusion, this case highlights a novel therapeutic approach for persistent dysphagia in TBI, which should be considered in the management of dysphagia.

IMPROVE study protocol, investigating post-stroke local muscle vibrations to promote cerebral plasticity and functional recovery: a single-blind randomised controlled trial

INTRODUCTION

Spasticity is a frequent disabling consequence following a stroke. Local muscle vibrations (LMVs) have been proposed as a treatment to address this problem. However, little is known about their clinical and neurophysiological impacts when used repeatedly during the subacute phase post-stroke. This project aims to evaluate the effects of a 6-week LMV protocol on the paretic limb on spasticity development in a post-stroke subacute population.

METHODS AND ANALYSIS

This is an interventional, controlled, randomised, single-blind (patient) trial. 100 participants over 18 years old will be recruited, within 6 weeks following a first stroke with hemiparesis or hemiplegia. All participants will receive a conventional rehabilitation programme, plus 18 sessions of LMV (ie, continuously for 30 min) on relaxed wrist and elbow flexors: either (1) at 80 Hz for the interventional group or (2) at 40 Hz plus a foam band between the skin and the device for the control group.Participants will be evaluated at baseline, at 3 weeks and 6 weeks, and at 6 months after the end of the intervention. Spasticity will be measured by the modified Ashworth scale and with an isokinetic dynamometer. Sensorimotor function will be assessed with the Fugl-Meyer assessment of the upper extremity. Corticospinal and spinal excitabilities will be measured each time.

ETHICS AND DISSEMINATION

This study was recorded in a clinical trial and obtained approval from the institutional review board (Comité de protection des personnes Ile de France IV, 2021-A03219-32). All participants will be required to provide informed consent. The results of this trial will be published in peer-reviewed journals to disseminate information to clinicians and impact their practice for an improved patient's care.

TRIAL REGISTRATION NUMBER

Clinical Trial: NCT05315726 DATASET: EUDRAct.

Best Practice Guidelines for the Management of Patients with Post-Stroke Spasticity: A Modified Scoping Review

This article aims to provide a concise overview of the best available evidence for managing post-stroke spasticity. A modified scoping review, conducted following the PRISMA guidelines and the PRISMA Extension for Scoping Reviews (PRISMA-ScR), involved an intensive search on Medline and PubMed from 1 January 2000 to 31 August 2023. The focus was placed on high-quality (GRADE A) medical, rehabilitation, and surgical interventions. In total, 32 treatments for post-stroke spasticity were identified. Two independent reviewers rigorously assessed studies, extracting data, and evaluating bias using GRADE criteria. Only interventions with GRADE A evidence were considered. The data included the study type, number of trials, participant characteristics, interventions, parameters, controls, outcomes, and limitations. The results revealed eleven treatments supported by GRADE A evidence, comprising 14 studies. Thirteen were systematic reviews and meta-analyses, and one was randomized control trial. The GRADE A treatments included stretching exercises, static stretching with positional orthosis, transcutaneous electrical nerve stimulation, extracorporeal shock wave therapy, peripheral magnetic stimulation, non-invasive brain stimulation, botulinum toxin A injection, dry needling, intrathecal baclofen, whole body vibration, and localized muscle vibration. In conclusion, this modified scoping review highlights the multimodal treatments supported by GRADE A evidence as being effective for improving functional recovery and quality of life in post-stroke spasticity. Further research and exploration of new therapeutic options are encouraged.

Local vibration induces changes in spinal and corticospinal excitability in vibrated and antagonist muscles

Local vibration (LV) applied over the muscle tendon constitutes a powerful stimulus to activate the muscle spindle primary (Ia) afferents that project to the spinal level and are conveyed to the cortical level. This study aimed to identify the neuromuscular changes induced by a 30-min LV-inducing illusions of hand extension on the vibrated flexor carpi radialis (FCR) and the antagonist extensor carpi radialis (ECR) muscles. We studied the change of the maximal voluntary isometric contraction (MVIC, experiment 1) for carpal flexion and extension, motor-evoked potentials (MEPs, experiment 2), cervicomedullary motor-evoked potentials (CMEPs, experiment 2), and Hoffmann's reflex (H-reflex, experiment 3) for both muscles at rest. Measurements were performed before (PRE) and at 0, 30, and 60 min after LV protocol. A lasting decrease in strength was only observed for the vibrated muscle. The reduction in CMEPs observed for both muscles seems to support a decrease in alpha motoneurons excitability. In contrast, a slight decrease in MEPs responses was observed only for the vibrated muscle. The MEP/CMEP ratio increase suggested greater cortical excitability after LV for both muscles. In addition, the H-reflex largely decreased for the vibrated and the antagonist muscles. The decrease in the H/CMEP ratio for the vibrated muscle supported both pre- and postsynaptic causes of the decrease in the H-reflex. Finally, LV-inducing illusions of movement reduced alpha motoneurons excitability for both muscles with a concomitant increase in cortical excitability.NEW & NOTEWORTHY Spinal disturbances confound the interpretation of excitability changes in motor areas and compromise the conclusions reached by previous studies using only a corticospinal marker for both vibrated and antagonist muscles. The time course recovery suggests that the H-reflex perturbations for the vibrated muscle do not only depend on changes in alpha motoneurons excitability. Local vibration induces neuromuscular changes in both vibrated and antagonist muscles at the spinal and cortical levels.

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.

Effects of vibration therapy for post-stroke spasticity: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of vibration therapy (VT) in people with post-stroke spasticity (PSS) remains uncertain. This study aims to conduct a comprehensive meta-analysis to assess the effectiveness of VT in PSS.

METHODS

PubMed, Embase, Cochrane Library, Physiotherapy Evidence Database, and Web of Science were searched from inception to October 2022 for randomized controlled trials (RCTs) of VT in people with PSS. The primary outcome was spasticity, and secondary outcomes included pain, motor function, gait performance, and adverse events. A meta‑analysis was performed by pooling the standardized mean difference (SMD) with 95% confidence intervals (CI).

RESULTS

A total of 12 studies met the inclusion criteria. Overall, VT had significant effects on reducing spasticity (SMD = - 0.77, 95% CI - 1.17 to - 0.36, P < 0.01) and pain (SMD =  - 1.09, 95% CI - 1.74 to - 0.45, P < 0.01), and improving motor function (SMD = 0.42, 95% CI 0.21 to 0.64, P < 0.01) in people with PSS. However, VT had no significant effect on gait performance (SMD =  - 0.23, 95% CI - 0.56-0.10). In addition, subgroup differences in short-term anti-spasticity effects between different vibration subtypes, vibration frequencies, vibration durations, frequency of sessions, control therapy, spasticity distribution, and population classification were not significant.

CONCLUSION

We found that VT significantly alleviated spasticity and pain in people with PSS and improved motor function, but its effect on gait performance was unclear. However, further studies are needed to validate these findings.

Deep muscle stimulator in the treatment of post-stroke spasticity: A protocol for systematic review and meta-analysis

BACKGROUND

Spasticity is one of the most common complications and sequelae of stroke, with the main clinical manifestations being increased muscle tension, pain, stiffness, and other disorders. It not only increases the length of hospitalization and medical costs but also affects the quality of daily life and the stress of returning to society, increasing the burden on patients and their families. At present, 2 driver types of deep muscle stimulator (DMS) have been used in the clinical treatment of post-stroke spasticity (PSS) with good clinical results, but there is no evidence of clinical efficacy and safety. Therefore, this study aims to integrate direct and indirect comparative clinical evidence through a systematic review and network meta-analysis (NMA). According to the data, different driver types for DMS with the same body of evidence will be collected, analyzed, and sequenced in a quantitative and comprehensive manner and then screened for the optimal driver type of DMS device for PSS treatment. The study also aims to provide reference value and an evidence-based theoretical basis for the clinical optimization of DMS equipment selection.

METHODS

A comprehensive retrieval of China National Knowledge Infrastructure, Chinese scientific journal database, China biological feature database, Wanfang Chinese databases and the Cochrane Library, PubMed, Web of Science, and Embase foreign databases will be conducted. Randomized controlled trials of these 2 driver types of DMS devices combined with conventional rehabilitation training of PSS will be searched and published. The retrieval time is from the establishment of the database to December 20, 2022. The 2 first authors will screen references that meet the inclusion criteria, independently extract data according to predesigned rules, and assess the quality of the included studies and the risk of bias according to the Cochrane 5.1 Handbook criteria. R programming and Aggregate Data Drug Information System software will be used to perform a combined NMA of the data and to evaluate the probability of ranking for all interventions.

RESULTS

The NMA and probability ranking will determine the best driver type of DMS device for PSS.

CONCLUSION

This study will offer a comprehensive evidence-based approach to DMS therapy and assist doctors, PSS patients, and decision-makers in selecting a more efficient, secure, and cost-effective treatment option.

Effects of prolonged local vibration superimposed to muscle contraction on motoneuronal and cortical excitability

Introduction: Acute effects of prolonged local vibration (LV) at the central nervous system level have been well investigated demonstrating an altered motoneuronal excitability with a concomitant increase in cortical excitability. While applying LV during isometric voluntary contraction is thought to optimize the effects of LV, this has never been addressed considering the acute changes in central nervous system excitability. Materials and Methods: In the present study, nineteen healthy participants were engaged in four randomized sessions. LV was applied for 30 min to the relaxed flexor carpi radialis muscle (VIB_RELAXED) or during wrist flexions (i.e. intermittent contractions at 10% of the maximal voluntary contraction: 15 s ON and 15 s OFF; VIB_CONTRACT). A control condition and a condition where participants only performed repeated low-contractions at 10% maximal force (CONTRACT) were also performed. For each condition, motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials (CMEPs) elicited by corticospinal tract electrical stimulation were measured before (PRE) and immediately after prolonged LV (POST) to investigate motoneuronal and corticospinal excitability, respectively. We further calculated the MEP/CMEP ratio as a proxy of cortical excitability. Results: No changes were observed in the control nor CONTRACT condition. At POST, CMEP decreased similarly in VIB_RELAXED (-32% ± 42%, p < .001) and VIB_CONTRACT (-41% ± 32%, p < .001). MEP/CMEP increased by 110% ± 140% (p = .01) for VIB_RELAXED and by 120% ± 208% (p = .02) for VIB_CONTRACT without differences between those conditions. Discussion: Our results suggest that LV to the flexor carpi radialis muscle, either relaxed or contracted, acutely decreases motoneuronal excitability and induces some priming of cortical excitability.

Neuromotor prosthetic to treat stroke-related paresis: N-of-1 trial

Background

Functional recovery of arm movement typically plateaus following a stroke, leaving chronic motor deficits. Brain-computer interfaces (BCI) may be a potential treatment for post-stroke deficits

Methods

In this n-of-1 trial (NCT03913286), a person with chronic subcortical stroke with upper-limb motor impairment used a powered elbow-wrist-hand orthosis that opened and closed the affected hand using cortical activity, recorded from a percutaneous BCI comprised of four microelectrode arrays implanted in the ipsilesional precentral gyrus, based on decoding of spiking patterns and high frequency field potentials generated by imagined hand movements. The system was evaluated in a home setting for 12 weeks

Results

Robust single unit activity, modulating with attempted or imagined movement, was present throughout the precentral gyrus. The participant acquired voluntary control over a hand-orthosis, achieving 10 points on the Action Research Arm Test using the BCI, compared to 0 without any device, and 5 using myoelectric control. Strength, spasticity, the Fugl-Meyer scores improved.

Conclusions

We demonstrate in a human being that ensembles of individual neurons in the cortex overlying a chronic supratentorial, subcortical stroke remain active and engaged in motor representation and planning and can be used to electrically bypass the stroke and promote limb function. The participant’s ability to rapidly acquire control over otherwise paralyzed hand opening, more than 18 months after a stroke, may justify development of a fully implanted movement restoration system to expand the utility of fully implantable BCI to a clinical population that numbers in the tens of millions worldwide.

Stroke is a restriction of blood flow to part of the brain and can lead to chronic issues with a person’s ability to control the limbs. The aim of this study was to see if a new type of device could restore movement in a person with arm weakness due to a stroke that occurred a year earlier. In our trial, a sensor was implanted into the surface of the brain, near the site of the stroke, and was connected to a computer that generated a command to open and close the hand with a motorized brace worn on the hand. This person was able to use their own brain activity to trigger the brace and pick up and move objects. This research could support the development of similar medical devices to restore movement in people who have had strokes.

Serruya et al. test in an N-of-1 trial whether a wearable, powered exoskeletal orthosis, driven by a percutaneous, implanted brain–computer interface can restore voluntary upper extremity function following chronic hemiparesis subsequent to a cerebral subcortical stroke. Using this approach, voluntary opening of the paralyzed hand is restored.

Bite Force, Thickness, and Thermographic Patterns of Masticatory Muscles Post-Hemorrhagic Stroke

OBJECTIVE

Stroke is a neurological deficit of cerebrovascular origin, considered a 21st-century epidemic that causes functional changes in the human body. This study aimed to evaluate the stomatognathic system of patients after hemorrhagic stroke through the bite force, thickness, and skin temperature in the region of the masseter and temporalis muscles.

MATERIAL AND METHODS

Twenty-four subjects were divided into groups: post-hemorrhagic stroke; with right side of the affected body (n = 12) and without the neurological disorder (n = 12). Maximum molar bite force was verified using a digital dynamometer. Muscle thickness was measured using ultrasound images obtained at rest and during maximal voluntary contraction of the masseter and temporalis muscles. Thermographic camera was used to record the thermographic patterns of the masseter and temporalis muscles. Data were subjected to Student's t-test (P < .05).

RESULTS

The maximum molar bite force showed significant differences in the right (P = .04) and left (P = .03) sides, with a reduction in force in the post-hemorrhagic stroke group on the affected and unaffected sides. There was a significant difference (P < .05) in the thickness of the left temporal muscle at mandibular rest (P = .01) between groups. The post-hemorrhagic stroke group clinically presented greater muscle thickness in almost 100% of the muscles evaluated in both clinical conditions. There were no significant differences in skin temperature in the masseter and temporal muscles between the groups.

CONCLUSIONS

Our results suggest functional changes in the stomatognathic system of subjects after a hemorrhagic stroke, especially concerning molar bite force and masticatory muscle thickness in the temporal muscle (unaffected side).

Non-invasive physical therapy as salvage measure for ischemic skin flap: A literature review

This review focuses on the available evidence regarding the molecular mechanisms and treatment potential of several non-surgical physical therapies for managing flap ischemia to propose a non-invasive, economical, and simple treatment to improve flap survival. A review of the literature was conducted on the topics of various non-invasive methods for the treatment of ischemic necrosis of the distal end of the flap between 1988 and 2019. A total of 52 published studies were reviewed on the applications of hyperbaric oxygen therapy, electrical stimulation therapy, heat stress pretreatment, phototherapy, and vibration therapy to manage skin flap necrosis. The underlying molecular mechanisms of these physical therapies on revitalizing the dying skin flaps were discussed and preliminary clinical uses of these therapies to salvage the necrotic skin flaps were pooled and summarized for clarifying the safety and feasibility of these methods. Various physical therapy regimens have been ushered to manage necrotic development in cutaneous flaps. With the refinement of these new technologies and enhancement of related basic science research on vascular revitalization, the prevention and treatment of flap ischemia will enter a new era.