Relationship between ultrasonographic, electromyographic, and clinical parameters in adult stroke patients with spastic equinus: an observational study

Improving the Reliability of Muscle Tissue Characterization Post-Stroke: A Secondary Statistical Analysis of Echotexture Features

Background/Objectives: Ultrasound (US) imaging and echotexture analysis are emerging techniques for assessing muscle tissue quality in the post-stroke population. Clinical studies suggest that echovariation (EV) and echointensity (EI) serve as objective indicators of muscle impairment, although methodological limitations hinder their clinical translation. This secondary analysis aimed to refine the assessment of echotexture by using robust statistical techniques. Methods: A total of 130 regions of interest (ROIs) extracted from the gastrocnemius medialis of 22 post-stroke individuals were analyzed. First, inter-examiner reliability between two physiotherapists was assessed by using Cohen's kappa for muscle impairment classification (low/high) for each echotexture feature. For each examiner, the correlation between the classification of the degree of impairment and the modified Heckmatt scale for each feature was analyzed. The dataset was then reduced to 44 ROIs (one image per leg per patient) and assessed by three physiotherapists to analyze inter-examiner reliability by using Light´s kappa and correlation between both assessment methods globally. Statistical differences in 21 echotexture features were evaluated according to the degree of muscle impairment. A binary logistic regression model was developed by using features with a Cohen's kappa value greater than 0.9 as predictors. Results: A strong and significant degree of agreement was observed among the three examiners regarding the degree of muscle impairment (Kappalight = 0.85, p < 0.001), with nine of the 21 features showing excellent inter-examiner reliability. The correlation between muscle impairment classification with the modified Heckmatt scale was very high and significant both globally and for each echotexture feature. Significant differences (<0.05) were found for EV, EI, dissimilarity, energy, contrast, maximum likelihood, skewness, and the modified Heckmatt scale. Logistic regression highlighted dissimilarity, entropy, EV, Gray-Level Uniformity (GLU), and EI as the main predictors of muscle tissue impairment. The EV and EI models showed high explanatory power (Nagelkerke's pseudo-R2 = 0.74 and 0.76) and robust classification performance (AUC = 94.20% and 95.45%). Conclusions: This secondary analysis confirms echotexture analysis as a reliable tool for post-stroke muscle assessment, validating EV and EI as key indicators while identifying dissimilarity, entropy, and GLU as additional relevant features.

Does the Diffusion Profile Differ Between Botulinum Toxin Type a Formulations? Implications for the Management of Post-Stroke Spasticity

Botulinum toxin type A is a first-line treatment for post-stroke spasticity, with selective action at nerve endings and minimal effects beyond the injection site. However, concerns about potential adverse reactions due to toxin diffusion and spread can significantly influence physicians' therapeutic decisions in managing post-stroke spasticity. Current evidence shows that while the main formulations of botulinum toxin type A have different molecular weights and sizes, they do not exhibit differing diffusion profiles. Instead, the key factors determining botulinum toxin type A diffusion and spread in post-stroke spasticity management are the dose (i.e., the actual amount of 150 kDa neurotoxin protein injected), dilution, and injection volume. Other injection-related factors, such as the needle gauge and injection speed, have also been suggested to have a secondary influence on botulinum toxin type A diffusion and spread. The needs of patients with post-stroke spasticity may vary, and depending on treatment goals, botulinum toxin type A diffusion and spread can be something to avoid or may offer therapeutic benefits by reaching a greater number of nerve terminals in the target muscle, enhancing the toxin's effect. These factors should be carefully evaluated in spasticity clinics.

Is the Silfverskiöld Test a valid tool for evaluating calf muscles spastic overactivity in patients with stroke? A retrospective observational study

BACKGROUND

Spastic equinus (plantar flexed) foot is a common postural pattern in patients who suffer from post-stroke spasticity. To date, some clinicians use the Silfverskiöld Test in their practice to differentiate between gastrocnemius and soleus muscle overactivity in patients with spastic equinus (plantar flexed) foot. This use of the Silfverskiöld Test goes beyond its original aim, which was to distinguish isolated gastrocnemius contracture in patients with equinus deformity.

AIM

The aim of this study was to investigate the Silfverskiöld Test validity for evaluating spastic equinus (plantar flexed) foot (i.e., differentiation between gastrocnemius and soleus muscle overactivity) by checking its outcome against those of selective diagnostic nerve block of tibial motor nerve branches to the soleus, gastrocnemius and tibialis posterior muscles.

DESIGN

The design of the study was retrospective observational.

SETTING

The study was set in a university hospital.

POPULATION

Sixty-seven adult stroke patients with spastic equinus (plantar flexed) foot.

METHODS

Each patient underwent selective diagnostic nerve block of tibial motor nerve branches to the soleus, gastrocnemius and tibialis posterior muscles. All patients were evaluated before diagnostic nerve block by means of the Silfverskiöld Test which was considered positive when ankle joint passive dorsiflexion was greater with the knee flexed than extended. Furthermore, they were assessed before and after nerve block by means of the modified Ashworth Scale and the Tardieu Scale.

RESULTS

Our sample included 41 males and 26 females (mean age 57.6 years) suffering from spastic equinus (plantar flexed) foot due to chronic stroke (mean time from onset 2.4 years). Forty-eight patients out of 67 presented with positive Silfverskiöld Test. The χ2 test showed no association between the Silfverskiöld Test and spastic overactivity of the gastrocnemius (P=0.253), soleus (P=0.605) and tibialis posterior (P=0.462) muscles as evaluated by serial selective diagnostic block of the tibial nerve motor branches.

CONCLUSIONS

Our findings do not support the Silfverskiöld Test as a valid tool for evaluating spastic equinus (plantar flexed) foot to differentiate between gastrocnemius, soleus and tibialis posterior spastic muscle overactivity in adult patients with stroke.

CLINICAL REHABILITATION IMPACT

The choice for an appropriate management of spastic equinus (plantar flexed) foot in adults with stroke should not be mainly defined on the base of Silfverskiöld Test.

Canadian Physicians' Use of Ultrasound in Spasticity Treatment: A National Cross-Sectional Survey

Objective

To identify potential barriers and obstacles preventing clinicians from adopting ultrasound for spasticity management.

Design

A prospective, cross-sectional national survey.

Setting

Web-based platform.

Participants

Thirty-six physicians and surgeons from across Canada.

Interventions

Survey completion.

Main Outcome Measures

The use of ultrasound in clinical spasticity practice, perceived barriers, and risks associated with its implementation.

Results

In total, 36 Canadian physicians and surgeons responded. A total of 91% reported using the US in their practice. Nearly all of them used ultrasonography (US) to guide injections and reported using more than 1 guidance technique for their injections. Less than half of the survey respondents reported using the US for muscle architecture assessment or longitudinal evaluation of muscle echo intensity. A total of 47% of survey respondents reported that they believe there are disadvantages associated with US use in spasticity practice. Disadvantages included increased time requirements resulting in discomfort for the injector and patient, the risk of infection after the procedure, and the risk of needle-stick injury. The most important barrier identified was the increased time demands of US compared with other guidance techniques. Other barriers included a lack of feedback on identifying a spastic muscle compared with electrical guidance techniques, a lack of additional remuneration to complete injections under ultrasound guidance, and a lack of adequate training.

Conclusions

Future educational efforts should address clinicians' lack of familiarity with US purposes outside of injection guidance. This survey has highlighted the need for a curriculum shift in spasticity education to improve physician's scanning and injection technique, to address concerns about increased time requirements for injecting under ultrasound guidance and to address perceived disadvantages from clinicians.

Assessing muscle architecture with ultrasound: implications for spasticity

Botulinum Neurotoxin Type A (BoNT-A) injections using Ultrasound (US) guidance have led to research evaluating changes in muscle architecture. Controversy remains as to what constitutes increased Echo-Intensity (EI) in spastic muscles and whether this may affect outcomes. We aim to provide a narrative review of US muscle architecture changes following Central Nervous System (CNS) lesions and explore their relationship to spasticity. Medline, CINAHL, and Embase databases were searched with keywords: ultrasonography, hypertonia, spasticity, fibrosis, and Heckmatt. Three physicians reviewed the results of the search to select relevant papers. Reviews identified in the search were used as a resource to identify additional studies. A total of 68 papers were included. Four themes were identified, including histopathological changes in spastic muscle, effects of BoNT-A on the muscle structure, available US modalities to assess the muscle, and utility of US assessment in clinical spasticity. Histopathological studies revealed atrophic and fibro-fatty changes after CNS lesions. Several papers described BoNT-A injections contributing to those modifications. These changes translated to increased EI. The exact significance of increased muscle EI remains unclear. The Modified Heckmatt Scale (MHS) is a validated tool for grading muscle EI in spasticity. The use of the US may be an important tool to assess muscle architecture changes in spasticity and improve spasticity management. Treatment algorithms may be developed based on the degree of EI. Further research is needed to determine the incidence and impact of these EI changes in spastic muscles.

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.

Quantitative assessment of spasticity: a narrative review of novel approaches and technologies

Spasticity is a complex neurological disorder, causing significant physical disabilities and affecting patients' independence and quality of daily lives. Current spasticity assessment methods are questioned for their non-standardized measurement protocols, limited reliabilities, and capabilities in distinguishing neuron or non-neuron factors in upper motor neuron lesion. A series of new approaches are developed for improving the effectiveness of current clinical used spasticity assessment methods with the developing technology in biosensors, robotics, medical imaging, biomechanics, telemedicine, and artificial intelligence. We investigated the reliabilities and effectiveness of current spasticity measures employed in clinical environments and the newly developed approaches, published from 2016 to date, which have the potential to be used in clinical environments. The new spasticity scales, taking advantage of quantified information such as torque, or echo intensity, the velocity-dependent feature and patients' self-reported information, grade spasticity semi-quantitatively, have competitive or better reliability than previous spasticity scales. Medical imaging technologies, including near-infrared spectroscopy, magnetic resonance imaging, ultrasound and thermography, can measure muscle hemodynamics and metabolism, muscle tissue properties, or temperature of tissue. Medical imaging-based methods are feasible to provide quantitative information in assessing and monitoring muscle spasticity. Portable devices, robotic based equipment or myotonometry, using information from angular, inertial, torque or surface EMG sensors, can quantify spasticity with the help of machine learning algorithms. However, spasticity measures using those devices are normally not physiological sound. Repetitive peripheral magnetic stimulation can assess patients with severe spasticity, which lost voluntary contractions. Neuromusculoskeletal modeling evaluates the neural and non-neural properties and may gain insights into the underlying pathology of spasticity muscles. Telemedicine technology enables outpatient spasticity assessment. The newly developed spasticity methods aim to standardize experimental protocols and outcome measures and enable quantified, accurate, and intelligent assessment. However, more work is needed to investigate and improve the effectiveness and accuracy of spasticity assessment.

Do Intramuscular Temperature and Fascicle Angle Affect Ultrasound Echo Intensity Values?

PURPOSE

Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle "quality" with physical training, disuse, aging, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate experiments to investigate the effects of muscle temperature and fascicle angle, which are known to influence muscle tissue and sound wave properties and therefore affect EI.

METHODS

In experiment 1 ( n = 16, 28.0 ± 6.6 yr), vastus lateralis (VL) ultrasonographic images were acquired and intramuscular temperature continuously recorded for 15 min after 20 min of heating to 40.4°C ± 0.7°C using a microwave device. In experiment 2 ( n = 17, 30.2 ± 9.8 yr), VL sonographic images were obtained with the knee both fully extended (0°) and flexed to 90° and EI and fascicle angle measured post hoc . Fascicle movement was tracked during the passive knee flexion to ensure that sonographic images were obtained at the same muscle region. Knee flexion reduced muscle thickness, and we therefore reran analyses calculating EI using identical dimensions to minimize this effect.

RESULTS

EI decreased only immediately after the passive heating, and although a moderate, negative correlation was observed between EI and temperature ( rrm = -0.36), the effect of muscle temperature was small ( β = 0.97 (-1.89 to -0.06) per degree Celsius, P = 0.051). Nonetheless, EI increased as fascicle angle decreased, and a large, negative correlation ( rrm = -0.85) was observed; the effect of fascicle angle on EI was large ( β = 3.0 (-3.8 to -2.2) per degree, P < 0.01), and this was maintained when analyses were performed at a constant depth of the region of interest ( β = 3.5 (-4.4 to -2.7) per degree, P < 0.01).

CONCLUSIONS

These findings support the hypothesis that fascicle angle meaningfully affects VL EI but provides weak evidence of a temperature effect in vivo . Thus, acute fascicle angle alterations should be accounted for in studies using EI measurements, and longer-term studies should consider whether changes in EI might be partly explained by a change in fascicle angle.

Management Of Spastic Equinovarus Foot in Children with Cerebral Palsy: An Evaluation of Anatomical Landmarks for Selective Nerve Blocks of the Tibial Nerve Motor Branches

OBJECTIVE

To define the anatomical landmarks of tibial motor nerve branches for selective motor nerve blocks of the gastrocnemii,  soleus and tibialis posterior muscles in the management of spastic equinovarus foot.

DESIGN

Observational study.

PATIENTS

Twenty-four children with cerebral palsy with spastic equinovarus foot.

METHODS

Considering the affected leg length, motor nerve branches to the gastrocnemii, soleus and tibialis posterior muscles were tracked using ultrasonography, and located in the space (vertical, horizontal, deep) according to the position of fibular head (proximal/distal) and a virtual line from the middle of popliteal fossa to the Achilles tendon insertion (medial/lateral).

RESULTS

Location of motor branches was defined as percentage of the affected leg length. Mean coordinates were: for the gastrocnemius medialis 2.5 ± 1.2% vertical (proximal), 1.0 ± 0.7% horizontal (medial), 1.5 ± 0.4% deep; for the gastrocnemius lateralis 2.3 ± 1.4% vertical (proximal), 1.1 ± 0.9% horizontal (lateral), 1.6 ± 0.4% deep; for the soleus 2.1 ± 0.9% vertical (distal), 0.9 ± 0.7% horizontal (lateral), 2.2 ± 0.6% deep; for the tibialis posterior 2.6 ± 1.2% vertical (distal), 1.3 ± 1.1% horizontal (lateral), 3.0 ± 0.7% deep.

CONCLUSION

These findings may help the identification of tibial motor nerve branches to perform selective nerve blocks in patients with cerebral palsy with spastic equinovarus foot.

Shear Wave Velocity to Evaluate the Effect of Botulinum Toxin on Post-Stroke Spasticity of the Lower Limb

(1) Background: The evaluation of muscles with spasticity using ultrasound elastography has attracted attention recently, and the shear wave velocity (SWV) technique can measure the mechanical properties of tissues objectively and quantitatively. The purpose of this study was to evaluate the effect of using SWV to assess the effect of Botulinum toxin type A (BoNT-A) treatment in adult patients with post-stroke lower limb spasticity. (2) Methods: We assessed the modified Ashworth Scale, the modified Tardieu Scale, and SWV at rest and after stretching before and at 1 month after BoNT-A treatment in 10 adult participants with post-stroke lower limb spasticity. (3) Results: Significant changes in SWV of the ankle joint in maximum dorsiflexion to the extent possible (SWV stretched) were observed after BoNT-A treatment. SWV stretched was positively correlated with joint range of motion. Participants whose joint range of motion did not improve (i.e., gastrocnemius medialis muscle (GCM) extension distance did not change) had significantly more reductions in SWV stretched after BoNT-A treatment. (4) Conclusions: Our results suggest that the SWV measurements may serve as a quantitative assessment to determine the effect of the BoNT-A treatment in adult stroke patients. SWV measurements to assess GCM spasticity should consider the effects of tension, material properties and activation level of muscles. The challenge is to measure SWV with matching limb positions in patients without contractures.

Technology-assisted assessment of spasticity: a systematic review

BACKGROUND

Spasticity is defined as "a motor disorder characterised by a velocity dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks". It is a highly prevalent condition following stroke and other neurological conditions. Clinical assessment of spasticity relies predominantly on manual, non-instrumented, clinical scales. Technology based solutions have been developed in the last decades to offer more specific, sensitive and accurate alternatives but no consensus exists on these different approaches.

METHOD

A systematic review of literature of technology-based methods aiming at the assessment of spasticity was performed. The approaches taken in the studies were classified based on the method used as well as their outcome measures. The psychometric properties and usability of the methods and outcome measures reported were evaluated.

RESULTS

124 studies were included in the analysis. 78 different outcome measures were identified, among which seven were used in more than 10 different studies each. The different methods rely on a wide range of different equipment (from robotic systems to simple goniometers) affecting their cost and usability. Studies equivalently applied to the lower and upper limbs (48% and 52%, respectively). A majority of studies applied to a stroke population (N = 79). More than half the papers did not report thoroughly the psychometric properties of the measures. Analysis identified that only 54 studies used measures specific to spasticity. Repeatability and discriminant validity were found to be of good quality in respectively 25 and 42 studies but were most often not evaluated (N = 95 and N = 78). Clinical validity was commonly assessed only against clinical scales (N = 33). Sensitivity of the measure was assessed in only three studies.

CONCLUSION

The development of a large diversity of assessment approaches appears to be done at the expense of their careful evaluation. Still, among the well validated approaches, the ones based on manual stretching and measuring a muscle activity reaction and the ones leveraging controlled stretches while isolating the stretch-reflex torque component appear as the two promising practical alternatives to clinical scales. These methods should be further evaluated, including on their sensitivity, to fully inform on their potential.

Botulinum Toxin a Injection Combined with Radial Extracorporeal Shock Wave Therapy in Children with Spastic Cerebral Palsy: Shear Wave Sonoelastographic Findings in the Medial Gastrocnemius Muscle, Preliminary Study

Therapeutic strategies to boost the effect of botulinum toxin may lead to some advantages, such as long lasting effects, the injection of lower botulinum toxin dosages, fewer side effects, and lower costs. The aim of this study is to investigate the combined effect of botulinum toxin A (BTA) injection and extracorporeal shock wave therapy (ESWT) for the treatment of spasticity in children with spastic cerebral palsy (CP). Fifteen patients with spastic CP were recruited through a retrospective chart review to clarify what treatment they received. All patients received a BTA injection on gastrocnemius muscle (GCM), and patients in group 1 underwent one ESWT session for the GCM immediately after BTA injection and two consecutive ESWT sessions at weekly intervals. Ankle plantar flexor and the passive range of motion (PROM) of ankle dorsiflexion were measured by a modified Ashworth scale (MAS) before treatment and at 1 and 3 month(s) post-treatment. In group 1, the shear wave velocity (SWV) of GCM was measured. The PROM and MAS in group 1 and 2 before treatment significantly improved at 1 and 3 month(s) after treatment. The change in PROM was significantly different between the two groups at 1 and 3 month(s) after treatment. The SWV before treatment significantly decreased at 1 month and 3 months after treatment in group 1. Our study has shown that the combination of BTA injection and ESWT would be effective at controlling spasticity in children with spastic CP, with sustained improvement at 3 months after treatment.

Relationship between longitudinal changes in skeletal muscle characteristics over time and functional recovery during intensive rehabilitation of patients with subacute stroke

BACKGROUND

Stroke is a disease that easily impairs skeletal muscle characteristics, resulting in low quantity, low quality, and poor strength. However, the recovery process of skeletal muscles in patients with stroke is not well established.

OBJECTIVES

We aimed to determine the longitudinal changes in skeletal muscle characteristics in patients with stroke during intensive rehabilitation and examine their relationship with functional recovery.

METHODS

Eighty-five patients with stroke were prospectively recruited. We defined muscle quantity and quality as ultrasonographic muscle thickness and echo intensity, respectively, and muscle strength as knee extension strength. These skeletal muscle characteristics were compared at four time points: on admission, after 2 weeks, after 4 weeks, and at discharge. We also explored the relationship between changes in skeletal muscle characteristics and functional recovery.

RESULTS

Non-paretic knee extension torque (F = 5.838, P = .001), paretic quadriceps thickness (F = 2.943, P = .039), and paretic tibialis anterior thickness (F = 4.654, P = .004) improved over time, and changes in the paretic side quadriceps thickness were significantly associated with recovery for balance ability (odds ratio, 1.05; 95% confidence interval, 1.00-1.09; P = .048).

CONCLUSIONS

The present study revealed that knee extension muscle strength on the non-paretic side and quadriceps and tibialis anterior thickness on the paretic side significantly improved over time and that changes in the paretic side quadriceps thickness were associated with the recovery of balance ability.

Contribution of Single-Fiber Evaluation on Monitoring Outcomes Following Injection of Botulinum Toxin-A: A Narrative Review of the Literature

Botulinum toxin-A (BoNT-A) blocks acetylcholine release at the neuromuscular junction (NMJ) and is widely used for neuromuscular disorders (involuntary spasms, dystonic disorders and spasticity). However, its therapeutic effects are usually measured by clinical scales of questionable validity. Single-fiber electromyography (SFEMG) is a sensitive, validated diagnostic technique for NMJ impairment such as myasthenia. The jitter parameter (µs) represents the variability of interpotential intervals of two muscle fibers from the same motor unit. This narrative review reports SFEMG use in BoNT-A treatment. Twenty-four articles were selected from 175 eligible articles searched in Medline/Pubmed and Cochrane Library from their creation until May 2020. The results showed that jitter is sensitive to early NMJ modifications following BoNT-A injection, with an increase in the early days’ post-injection and a peak between Day 15 and 30, when symptoms diminish or disappear. The reappearance of symptoms accompanies a tendency for a decrease in jitter, but always precedes its normalization, either delayed or nonexistent. Increased jitter is observed in distant muscles from the injection site. No dose effect relationship was demonstrated. SFEMG could help physicians in their therapeutic evaluation according to the pathology considered. More data are needed to consider jitter as a predictor of BoNT-A clinical efficacy.

Does Botulinum Toxin Treatment Affect the Ultrasonographic Characteristics of Post-Stroke Spastic Equinus? A Retrospective Pilot Study

Equinovarus/equinus foot is a pattern most commonly treated with botulinum toxin type A in patients with post-stroke spasticity involving the lower limbs; the gastrocnemius is the muscle most frequently injected. Spastic equinovarus/equinus can present a mixture of conditions, including spasticity, muscle/tendon shortening, muscle weakness and imbalance. In this study, we wanted to determine whether botulinum toxin treatment affects the ultrasonographic characteristics of post-stroke spastic equinus. The same dose of AbobotulinumtoxinA was injected into the gastrocnemius medialis and lateralis of 21 chronic stroke patients with spastic equinus. Clinical (Ashworth scale and ankle range of motion) and ultrasound (conventional and sonoelastography) evaluation of the treated leg was carried out before and 4 weeks after injection. No significant effects of botulinum toxin treatment on the ultrasonographic characteristics of spastic equinus were observed. As expected, there were significant improvements in ankle passive dorsiflexion range of motion and calf muscle spasticity at 1 month after treatment. There was a direct association between Achilles tendon elasticity and calf muscle spasticity at baseline evaluation. Larger studies with a long-term timeline of serial evaluations are needed to further investigate the possible effects of botulinum toxin injection on spastic muscle characteristics in patients with post-stroke spasticity.

Muscle and tendon properties of the spastic lower leg after stroke defined by ultrasonography: a systematic review

INTRODUCTION

Peripheral muscle and tendon changes after stroke can influence the functional outcome of patients. The aim of this systematic review was to summarize the evidence of ultrasonographic changes in morphological muscle and tendon properties of the spastic hemiparetic lower leg in patients with first ever stroke.

EVIDENCE ACQUISITION

A systematic search was conducted through PubMed, Embase, Scopus, Cinahl, Cochrane Library, and manual searches from inception until May 1, 2020. Observational case control or cohort studies were included. Risk of bias was evaluated by using the Newcastle-Ottawa Quality Assessment Scale. Outcome parameters of interest included muscle thickness, muscle and tendon length, fascicle length, pennation angle and echo-intensity.

EVIDENCE SYNTHESIS

Nine studies investigated outcome parameters beyond one-month after stroke. We are unable to make a comprehensive statement. Nevertheless, there are some arguments for reduced muscle thickness and reduced fascicle length of the hemiplegic, spastic leg.

CONCLUSIONS

Despite the fact that objective assessment by ultrasonography holds promise for diagnosis and follow-up of spastic hemiparesis after stroke, more evidence is needed to determine how changes in morphological muscle and tendon properties are related to muscle weakness, severity of spasticity and compensation strategies such as disuse or overuse in longitudinal studies starting early after stroke.

Pain and Muscles Properties Modifications After Botulinum Toxin Type A (BTX-A) and Radial Extracorporeal Shock Wave (rESWT) Combined Treatment

BACKGROUND AND OBJECTIVE

Spasticity (most common disability in upper motor neuron syndrome or UMNS) caused an inability of patients' to perform daily activities and a decrease inquality of life. One of the promising methods nowadays, but still not widely used in everyday practice, for spasticity reduction is extracorporeal shock wave. The aim of this study was to evaluate the objective clinical effects of combined treatment botulinum toxin type A and radial Extracorporeal Shock Wave Therapy in spasticity post stroke.

METHODS

We considered 30 subjects (14 female and 16 male) with post stroke spasticity of Biceps Brachii, Superficial Flexor Digitorum, Gastrocnemius Medialis and Lateralis and we divided patients into two groups (group A received botulinum toxin injection and physiotherapy while group B received botulinum toxin injection, rESWT and physiotherapy). Assessments were performed before treatment (t0), after 1 (t1), 2 (t2) e 3 (t3) months using Modified Ahworth Scale, Visual Analogical Scale for pain and MyotonPro® device (to assessed myometric evaluation of muscles tone and stiffness).

RESULTS

Visual Analogical Scale, Modified Ahworth Scale, muscles tone and stiffness statistically decreased until t3 in the group A and in the group B, but the differences between the two groups were significant at the t1 only.

CONCLUSION

Radial Extracorporeal Shock Wave Therapy could be an effective physical treatment aimed at the reduction of upper and lower limbs spasticity and could lead to the improvement of trophic conditions of the spastic muscles in post-stroke.

Long-term use of implanted peroneal functional electrical stimulation for stroke-affected gait: the effects on muscle and motor nerve

BACKGROUND

Peripheral changes to muscle and motor nerves occur following stroke, which may further impair functional capacity. We investigated whether a year-long use of an implanted peroneal FES system reverses stroke-related changes in muscles and motor nerves in people with foot drop in the chronic phase after supratentorial stroke.

METHODS

Thirteen persons with a chronic stroke (mean age 56.1 years, median Fugl-Meyer Assessment leg score 71%) were included and received an implanted peroneal FES system (ActiGait®). Quantitative muscle ultrasound (QMUS) images were obtained bilaterally from three leg muscles (i.e. tibialis anterior, rectus femoris, gastrocnemius). Echogenicity (muscle ultrasound gray value) and muscle thickness were assessed over a one-year follow-up and compared to age-, sex-, height- and weight-corrected reference values. Compound motor action potentials (CMAPs) and motor evoked potentials (MEPs) were obtained from the tibialis anterior muscle. Generalized estimated equation modeling was used to assess changes in QMUS, CMAPs and MEPs outcomes over the follow-up period.

RESULTS

Echogenicity of the tibialis anterior decreased significantly during the follow-up on the paretic side. Z-scores changed from 0.88 at baseline to - 0.15 after 52 weeks. This was accompanied by a significant increase in muscle thickness on the paretic side, where z-scores changed from - 0.32 at baseline to 0.48 after 52 weeks. Echogenicity of the rectus femoris normalized on both the paretic and non-paretic side (z-scores changed from - 1.09 and - 1.51 to 0.14 and - 0.49, respectively). Amplitudes of CMAP and MEP (normalized to CMAP) were reduced during follow-up, particularly on the paretic side (ΔCMAP = 20% and ΔMEP = 14%).

CONCLUSIONS

We show that the structural changes to muscles following stroke are reversible with FES and that these changes might not be limited to electrically stimulated muscles. No evidence for improvement of the motor nerves was found.

Cross-sectional study of quadriceps properties and postural stability in patients with chronic stroke and limited vs. non-limited community ambulation

Background: Changes in the paretic-side metabolism post-stroke and quadriceps muscle mechanical properties favour muscle wasting, affecting postural instability and walking impairment. Further clarification is needed in subjects post-stroke who show limited or non-limited community ambulation. Objectives: To analyze between-limb differences in quadriceps muscle thickness, strength and thigh cutaneous temperature, as well as investigate postural stability in subjects with chronic stroke and limited vs. non-limited community ambulation and compared against healthy controls. Methods: In this controlled cross-sectional study, 26 participants with chronic hemiparesis post-stroke (divided in a slow gait group (SG<0.8 m/s) (n = 13) and a fast gait group with full community ambulation speed (FG≥0.8 m/s)) and 18 healthy people were recruited. Thigh surface temperature, rectus femoris (RF) and vastus intermedius (VI) muscles thickness, quadriceps' isometric maximal voluntary contraction and postural stability were measured. Results: The SG presented significantly lower RF (P = .019) and VI (P = .006) muscle thickness, less peak force (P < .001) and lower temperature (P = .002) in the paretic vs the non-paretic limb. The FG showed significantly lower VI thickness (P = .036) and peak force (P < .001) in the paretic vs the non-paretic limb. Regarding balance, all indices were worse in the SG versus the FG and CG. Conclusions: Subjects of the FG, despite showing full community ambulation speed, had less quadriceps strength and VI muscle thickness but not RF muscle wasting in the paretic limb. The paretic VI muscle wasting may be an important factor to reach normal walking. The SG showed between-limb differences in all the studied variables and the worst postural stability.

Electrodiagnostic and nerve ultrasonographic features in upper limb spasticity: an observational study

To better understand the effects of spasticity on peripheral nerves, we evaluated the electrodiagnostic and nerve ultrasonographic features of the median and ulnar nerves in adults with upper limb spasticity. Twenty chronic stroke patients with spastic hemiparesis underwent nerve conduction study and nerve ultrasonography of the median and ulnar nerves at both upper limbs. Affected versus unaffected upper limb comparisons showed significant differences in the median and ulnar nerve distal motor latencies, compound muscle action potentials and F-wave minimal latencies. Furthermore, we observed a significantly greater median nerve crosssectional area at the elbow of the affected upper limb compared with the unaffected one. Our findings confirmed electrodiagnostic asymmetries and nerve ultrasonographic abnormalities in the affected versus the unaffected upper limb after stroke. Slight changes in lower motor neuron activity and spasticity might contribute to these alterations.

The Effect of Functional Stretching Exercises on Neural and Mechanical Properties of the Spastic Medial Gastrocnemius Muscle in Patients with Chronic Stroke: A Randomized Controlled Trial

BACKGROUND

Following spasticity, neural and mechanical changes of the paretic muscle often occur, which affect the muscle function. The aim of this study was to investigate the effect of functional stretching exercises on neural and mechanical properties of the spastic muscle in patients with stroke.

MATERIALS AND METHODS

This study was a single-blinded, randomized control trial. Forty five patients with stroke (experimental group: n = 30; control group: n = 15) participated in this study. Subjects in the experimental group participated in a functional stretching program 3 times a week for 4 weeks. Subjects in both groups were evaluated before the training, at the end of training, and then during a 2-month follow-up. Neural properties, including H-reflex latency and Hmax/Mmax ratio, were acquired. Mechanical properties, including fascicle length, pennation angle, and muscle thickness in the spastic medial gastrocnemius muscle, were evaluated. Repeated measure analysis of variance was used in the analysis.

RESULTS

Time by group interaction in the pennation angle (P = .006), and in muscle thickness (P = .030) was significant. The results indicated that the H-reflex latency (P = .006), pennation angle (P < .001), and muscle thickness (P = .001) were altered after stretching training program and these changes were at significant level after 2-month follow-up.

CONCLUSION

The results indicated that the use of functional stretching exercises can cause significant differences in neural and mechanical properties of spastic medial gastrocnemius muscle in patients with chronic stroke.

The effect of dry needling on spasticity, gait and muscle architecture in patients with chronic stroke: A case series study

Objectives The objective of this study was to assess the short-term effects of dry needling on spasticity, gait, and muscle architecture of patients with chronic stroke. Methods A case series study was designed; and six chronic stroke patients with ankle spasticity and gait impairment received a single session of dry needling for gastrocnemius medialis, lateralis, and soleus muscles. The main outcome measures were the Modified Modified Ashworth Scale (MMAS), and Timed Up and Go test (TUG). In addition, ultrasonography measurements (e.g. thickness, pennation angle, and fascicle length) were performed for gastrocnemius medialis at baseline (T0), immediately after intervention (T1) and 30 min after intervention (T2), while the MMAS and TUG Test were only measured at T0 and T2. Results Based on the TUG test, there was a significant improvement in gait function (p = 0.023). Furthermore, the MMAS results (p = 0.014) showed a decrease in resistance to passive movements from plantar flexor muscles. Furthermore, a significant decrease in pennation angle (p = 0.014) and muscle thickness (p = 0.001), and also a significant increase in fascicle length of gastrocnemius medialis (p = 0.001) were observed after dry needling. Discussion & conclusions Based on the outcomes of this study, dry needling application seems to have short term effects in terms of reducing spasticity, improving gait, and muscle architecture of gastrocnemius medialis in patients with chronic stroke. The changes of muscle architecture may be interpreted as the positive effects of dry needling on the physical properties of hypertonic muscles.

"Appropriate Treatment" and Therapeutic Window in Spasticity Treatment with IncobotulinumtoxinA: From 100 to 1000 Units

Many neurological diseases (ischemic and hemorrhagic stroke, multiple sclerosis, infant cerebral palsy, spinal cord injuries, traumatic brain injury, and other cerebrovascular disorders) may cause muscle spasticity. Different therapeutic strategies have been proposed for the treatment of spasticity. One of the major treatments for tone modulation is botulinum toxin type A (BTX-A), performed in addition to other rehabilitation strategies based on individualized multidisciplinary programs aimed at achieving certain goals for each patient. Therapeutic plans must be precisely defined as they must balance the reduction of spastic hypertonia and retention of residual motor function. To perform and optimize the treatment, an accurate clinical and instrumental evaluation of spasticity is needed to determine how this symptom is invalidating and to choose the best doses, muscles and times of injection in each patient. We introduce an “appropriate treatment” and no “standard or high dosage treatment” concept based on our retrospective observational study on 120 patients lasting two years, according to the larger Therapeutic Index and Therapeutic Window of Incobotulinumtoxin A doses from 100 to 1000 units. We studied the efficiency and safety of this drug considering the clinical spasticity significance for specialist physicians and patients.

Relationships between muscle mass, intramuscular adipose and fibrous tissues of the quadriceps, and gait independence in chronic stroke survivors: a cross-sectional study

OBJECTIVE

To examine the relationships between muscle mass, intramuscular adipose and fibrous tissues of the quadriceps, and gait independence in chronic stroke survivors.

DESIGN

Cross-sectional study.

SETTING

Hospital-based research.

PARTICIPANTS

Seventeen chronic stroke survivors who were unable to walk independently (non-independent walker group) and 11 chronic stroke survivors who were able to walk independently (independent walker group) participated in this study. In addition, 25 healthy older adults (healthy group) were enrolled.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The muscle mass and intramuscular adipose and fibrous tissues of the rectus femoris and vastus intermedius were assessed based on muscle thickness and echo intensity of ultrasound images, respectively.

RESULTS

The thicknesses of the rectus femoris and vastus intermedius on the paretic and non-paretic sides in the non-independent walker group were significantly lower than those in the healthy group (mean difference -0.5 to -0.2cm; P<0.001-0.037). The paretic side in the non-independent walker group had significantly higher rectus femoris and vastus intermedius echo intensity compared with the healthy group (mean difference 15.8-17.4; P=0.007-0.025). The thickness of the rectus femoris on the non-paretic side was significantly lower in the independent walker group than in the healthy group (mean difference -0.3cm; P=0.001).

CONCLUSIONS

These results suggest that chronic stroke survivors who are unable to walk independently are likely to experience secondary changes in skeletal muscle on both the paretic and non-paretic sides.

Ultrasonographic Evaluation of Botulinum Toxin Injection Site for the Medial Approach to Tibialis Posterior Muscle in Chronic Stroke Patients with Spastic Equinovarus Foot: An Observational Study

The tibialis posterior muscle is a frequent target for injection of botulinum toxin during the management of spastic equinovarus foot in adults with post-stroke spasticity. Although it is deep-seated, the needle insertion into the tibialis posterior muscle is usually performed using anatomical landmarks and safety information obtained from healthy subjects and cadavers. Our aim was to evaluate the botulinum toxin injection site for the medial approach to the tibialis posterior muscle in chronic stroke patients with spastic equinovarus foot. Forty-six patients were evaluated at the affected middle lower leg medial surface with ultrasonography according to the following parameters: tibialis posterior muscle depth, thickness, and echo intensity. As to the spastic tibialis posterior, we found a mean muscle depth of 26.5 mm and a mean muscle thickness of 10.1 mm. Furthermore we observed a median tibialis posterior muscle echo intensity of 3.00 on the Heckmatt scale. The tibialis posterior muscle thickness was found to be inversely associated with its depth (p < 0.001) and echo intensity (p = 0.006). Furthermore, tibialis posterior muscle depth was found to be directly associated with its echo intensity (p = 0.004). Our findings may usefully inform manual needle placement into the tibialis posterior for the botulinum toxin treatment of spastic equinovarus foot in chronic stroke patients.

Effects of botulinum toxin A therapy and multidisciplinary rehabilitation on lower limb spasticity classified by spastic muscle echo intensity in post-stroke patients

OBJECTIVES

The purpose of the present study was to investigate retrospectively the relationship between botulinum toxin type A plus multidisciplinary rehabilitation and muscle echo intensity in post-stroke patients with spasticity. The primary aim was to investigate whether the effects of the intervention on the improvement of spasticity depend on muscle echo intensity, and the secondary aim was to investigate whether the motor function of the lower limbs depends on muscle echo intensity.

METHODS

A 12-day inpatient protocol was designed for 102 post-stroke patients with spasticity due to lower limb paralysis. Muscle echo intensity of the triceps surae muscle was measured by ultrasonography, and the patients were categorized into four groups based on Heckmatt scale grades (Grades I-IV).

RESULTS

All four groups classified by the Heckmatt scale showed significant pre-to-post-intervention differences in the knee and ankle modified Ashworth scale scores (p < 0.05). Grades I-III patient groups showed a significant improvement in lower limb motor function following intervention. Grade IV patients did not show a significant improvement in lower limb motor function.

CONCLUSIONS

We observed significant improvements in the modified Ashworth scale scores after botulinum toxin type A and multidisciplinary rehabilitation therapy on post-stroke patients with spasticity. Although patients with lower muscle echo intensity demonstrated improvements in motor function, the improvement was poor in those with higher muscle echo intensity.

The effect of functional stretching exercises on functional outcomes in spastic stroke patients: A randomized controlled clinical trial

BACKGROUND

Stroke is the biggest cause of disability in adults. Spasticity is a primary impairment of stroke with a highly variable prevalence. In the present research, we aimed to determine the impact of functional stretching exercises on functional outcomes in stroke patients.

METHODS

Thirty stroke patients were randomized into two groups-Experimental group and control group for the purposes of the study. The subjects in the experimental group participated in a functional stretching training program at the rehabilitation center thrice a week for four weeks. The subjects in both groups were evaluated in 3 intervals, once at baseline, once at the end of the program, and once at 2 months following the program. Clinical assessments, such as measuring spasticity, were conducted using the Modified Modified Ashworth Scale (MMAS). Functional outcomes were also evaluated, using the Timed Up and Go (TUG) test, as well as the Timed 10-Meter Walk Test (WTT). Friedman test in SPSS version 22.0 was used to analysis the response variables with respect to each stage of evaluation. Spearman rank correlation was also used to measure correlation among clinical assessments and functional outcomes.

RESULTS

The comparison between two groups showed significant differences only in the Modified Modified Ashworth Scale and Visual Analogue Scale (VAS) post treatment. The experimental group showed significant differences in the MMAS (p = 0.002), WTT (p < 0.001), and TUG (p < 0.001) scores. Nevertheless, the scores of the control group were not significantly different in different stages of evaluation.

CONCLUSION

The findings of the study suggest that using functional stretching exercises can improve functional outcomes in chronic spastic stroke patients.

Is spasticity always the same? An observational study comparing the features of spastic equinus foot in patients with chronic stroke and multiple sclerosis

Spasticity is common in stroke and multiple sclerosis. To treat spasticity we have a wide range of interventions, whose application may depend not only on the severity of spasticity but also on its etiology. Consequently, a better understanding of muscle spasticity in different neurological diseases may inform clinicians as to the more appropriate therapeutic approach. Our aim was to compare the clinical and ultrasonographic features of spastic equinus in patients with chronic stroke and multiple sclerosis. Thirty-eight patients with secondary progressive multiple sclerosis and 38 chronic stroke patients with spastic equinus were evaluated at the affected ankle according to the following outcomes: modified Ashworth scale, Tardieu scale, passive range of motion, spastic gastrocnemius muscle echo intensity and thickness. Affected calf muscles tone was significantly greater in patients with chronic stroke (modified Ashworth scale P=0.008; Tardieu scale angle P=0.004) as well as spastic gastrocnemius muscle echo intensity (P<0.001). Affected ankle range of motion was significantly greater in patients with multiple sclerosis (P<0.001) as well as spastic gastrocnemius muscle thickness (medialis: P=0.003; lateralis: P=0.004). Our findings evidenced that the same pattern of spasticity (equinus foot) has some different features according to its etiology. This may help the management of spasticity.

Sonographic and clinical effects of botulinum toxin Type A combined with extracorporeal shock wave therapy on spastic muscles of children with cerebral palsy

OBJECTIVE

The aim of this study was to compare the combined sonographic and clinical effects of botulinum toxin type A (BoNT-A) and extracorporeal shock wave therapy (ESWT) versus BoNT-A alone in children with cerebral palsy.

METHODS

Ten children with spastic cerebral palsy were randomly assigned to one of two groups. Group 1 received BoNT-A injection into the spastic muscles of the affected limbs plus three ESWT sessions. Group 2 received BoNT-A alone. Assessment was performed before and 1 month after injection. Sonographic outcomes were injected muscles echo intensity and their hardness percentage, and clinical outcomes the modified Ashworth scale and the Tardieu scale.

RESULTS

At 1-month evaluation, significant differences in the injected muscles percentage of hardness (P = 0.021) and the modified Ashworth scale (P = 0.001) were found between groups.

CONCLUSIONS

Our results support the hypothesis that the combined effects of BoNT-A and ESWT derive from their respective action on neurological and non-neural rheological components in spastic muscles.

Bilateral changes in muscle architecture of physically active people with chronic stroke: A quantitative muscle ultrasound study

OBJECTIVE

Changes in muscle architecture after stroke are usually assessed by investigating inter-limb differences. As a result bilateral changes of muscle architecture might be missed. Our aim was to investigate whether bilateral architectural changes in skeletal muscle can be detected in chronic, physically active stroke patients using quantitative muscle ultrasound (QMUS).

METHODS

Twenty-eight patients (mean time since stroke 5.2years, median Brunnström stage 4) were recruited. QMUS images were obtained bilaterally from 2 arm and 4 leg muscles. Corrected echogenicity (muscle ultrasound grayvalue) and muscle thickness were compared to reference values obtained from healthy subjects. Correlations of muscle changes with demographic, clinical and neurophysiological characteristics were explored.

RESULTS

Out of 6 muscles, a significant increase in mean echogenicity was found in 4 paretic and 3 non-paretic side muscles. Significant decreases in mean muscle thickness were found in 2 paretic side muscles and 1 non-paretic side muscle. Echogenicity of the medial gastrocnemius correlated moderately with walking speed (inversely) and time since stroke.

CONCLUSIONS

This study showed that QMUS is a feasible technique to investigate architectural changes in skeletal muscles in the chronic phase of stroke and that abnormalities can be found in muscles on both the hemiparetic and non-paretic side.

SIGNIFICANCE

Intriguing data on bilateral changes in muscles of people with stroke is presented. Directions for future research are provided.

Combined effects of transcranial direct current stimulation (tDCS) and transcutaneous spinal direct current stimulation (tsDCS) on robot-assisted gait training in patients with chronic stroke: A pilot, double blind, randomized controlled trial

PURPOSE

Preliminary evidence has shown no additional effects of transcranial direct current stimulation (tDCS) on robotic gait training in chronic stroke, probably due to the neural organization of locomotion involving cortical and spinal control. Our aim was to compare the combined effects of tDCS and transcutaneous spinal direct current stimulation (tsDCS) on robotic gait training in chronic stroke.

METHODS

Thirty chronic stroke patients received ten 20-minute robot-assisted gait training sessions, five days a week, for 2 consecutive weeks combined with anodal tDCS + sham tsDCS (group 1; n = 10) or sham tDCS + cathodal tsDCS (group 2; n = 10) or tDCS + cathodal tsDCS (group 3; n = 10). The primary outcome was the 6-minute walk test (6MWT) performed before, after, 2 weeks and 4 weeks post-treatment.

RESULTS

Significant differences in the 6MWT distance were noted between group 3 and group 1 at the post-treatment and 2-week follow-up evaluations (post-treatment P = 0.015; 2-week follow-up P = 0.001) and between group 3 and group 2 (post-treatment P = 0.010; 2-week follow-up P =  .015). No difference was found between group 2 and group 1.

CONCLUSIONS

Our preliminary findings support the hypothesis that anodal tDCS combined with cathodal tsDCS may be useful to improve the effects of robotic gait training in chronic stroke.

Pennation angle does not influence the age-related differences in echo intensity of the medial gastrocnemius

The reflection of an ultrasound (US) wave is strongest when the propagation direction of the wave is perpendicular to muscle fascicles. Thus, it is possible that muscle echo intensity (EI), a gray-scale US measure of muscle quality, may be influenced by the angulation of muscle fascicles. Therefore, the purpose of this study was to determine if age-related differences in muscle EI values are influenced by differences in pennation angle (PA). Medial gastrocnemius EI and PA were examined using panoramic US imaging in 24 young (19.8 ± 1.7 y) and 21 older (69.3 ± 3.3 y) men. The young men had lower EI values (young = 74.1 ± 6.3 a.u., older = 89.1 ± 8.8 a.u.) and a greater PA (young = 20.0 ± 2.9°; older = 17.2 ± 2.5°) compared with the older men (p < 0.01). In addition, there was a negative relationship (r = -0.473, p < 0.01) between PA and EI with both groups combined, but no significant relationship when the young (r = -0.334, p = 0.111) and older (r = -0.147, p = 0.525) men were examined separately. An analysis of covariance revealed that muscle EI values remained different (p < 0.01) between age groups after adjustment for differences in PA. Thus, after statistically adjusting the mean EI values for the differences in PA, there were still significant age-related differences in EI. These findings may provide further support that the age-related changes in muscle EI values reflect changes in tissue composition (i.e., increase in intramuscular fat and/or connective tissue) commonly reported in older adults.