Electrophysiological evaluation of the Modified Tardieu Scale (MTS) in assessing poststroke wrist flexor spasticity

Testing spasticity mechanisms in chronic stroke before and after intervention with contralesional motor cortex 1 Hz rTMS and physiotherapy

BACKGROUND

Previous studies showed that repetitive transcranial magnetic stimulation (rTMS) reduces spasticity after stroke. However, clinical assessments like the modified Ashworth scale, cannot discriminate stretch reflex-mediated stiffness (spasticity) from passive stiffness components of resistance to muscle stretch. The mechanisms through which rTMS might influence spasticity are also not understood.

METHODS

We measured the effects of contralesional motor cortex 1 Hz rTMS (1200 pulses + 50 min physiotherapy: 3×/week, for 4-6 weeks) on spasticity of the wrist flexor muscles in 54 chronic stroke patients using a hand-held dynamometer for objective quantification of the stretch reflex response. In addition, we measured the excitability of three spinal mechanisms thought to be related to post-stroke spasticity: post-activation depression, presynaptic inhibition and reciprocal inhibition before and after the intervention. Effects on motor impairment and function were also assessed using standardized stroke-specific clinical scales.

RESULTS

The stretch reflex-mediated torque in the wrist flexors was significantly reduced after the intervention, while no change was detected in the passive stiffness. Additionally, there was a significant improvement in the clinical tests of motor impairment and function. There were no significant changes in the excitability of any of the measured spinal mechanisms.

CONCLUSIONS

We demonstrated that contralesional motor cortex 1 Hz rTMS and physiotherapy can reduce the stretch reflex-mediated component of resistance to muscle stretch without affecting passive stiffness in chronic stroke. The specific physiological mechanisms driving this spasticity reduction remain unresolved, as no changes were observed in the excitability of the investigated spinal mechanisms.

Acupuncture in the Treatment of Abnormal Muscle Tone in Children with Cerebral Palsy: A Meta-Analysis

Objective

To analyse the clinical efficacy of acupuncture and routine treatment in improving dystonia in children with cerebral palsy.

Method

The randomized controlled trials published from the establishment of the databases to August 2022 on acupuncture in the treatment of dystonia in children with cerebral palsy were collected and comprehensively searched in China national knowledge infrastructure (CNKI), weipu (VIP), Wanfang, SinoMed, PubMed, Excerpta medica database (EMBASE), and Cochrane Library. The literature was selected according to the established standards, the quality of the included studies was evaluated, the heterogeneity of the included studies was evaluated with the I² test, and the appropriate model was selected for analysis. Sensitivity analysis was used to evaluate the reliability of the results, and a funnel plot was used to evaluate the publication bias.

Results

Fifteen studies were included in the meta-analysis. The control group was treated with routine treatment and acupuncture combined with routine treatment. The outcome index showed that the effect in the treatment group was better: Modified Ashworth Scale score: -0.52, 95% confidence interval (CI) (-0.62 to -0.41), p < 0.01. The treatment group showed reduced muscle tension to a greater extent (integral eletromyographic (iEMG) score: standard mean square deviation = -2.97, 95% CI (-4.87 to -1.06), p < 0.01). The effective rate in the control group was 74.2% and that in the treatment group was 91.5%, odds ratio = 3.70, 95% CI (2.02-6.78), p < 0.01. The funnel plot showed publication bias.

Conclusion

Acupuncture combined with routine training could improve muscle tension abnormalities and improve the efficiency of clinical treatment.

Validity and reliability of the Modified Tardieu Scale as a spasticity outcome measure of the upper limbs in adults with neurological conditions: a systematic review and narrative analysis

PURPOSE

To evaluate published evidence on the Modified Tardieu Scale (MTS) as a tool to assess spasticity in the upper limbs of adults with neurological conditions.

DATA SOURCES

A systematic search of six electronic databases (PubMed/MEDLINE, CINAHL, EMBASE, the Cochrane Library, Web of Science and Physiotherapy Evidence Database) from inception to 31 December 2020. A search strategy was developed using key elements of the research question: population, intervention (action), outcome.

STUDY ELIGIBILITY CRITERIA

Inclusion criteria: (1) adult participants with neurological conditions; (2) upper limb muscles/joints as tested elements; (3) studies testing the MTS and (4) reliability or validity reported.

EXCLUSION CRITERIA

(1) non-English articles; (2) non-empirical articles and (3) studies testing the Tardieu Scale.

STUDY APPRAISAL

Evidence quality was evaluated using the US National Heart, Lung, Blood Institute quality assessment tool for observational cohort and cross-sectional studies.

RESULTS

Six reliability studies met the inclusion criteria. Overall, most articles reported good-to-excellent levels of inter-rater, intrarater and test-retest reliability. However, limitations, such as study design weaknesses, statistical misuses and reporting biases, undermine confidence in reported conclusions. The validity of the MTS also remained questionable based on the results of one study.

CONCLUSIONS AND IMPLICATIONS

This review did not find sufficient evidence to either support or reject the use of the MTS in assessing spasticity in the upper limbs of adults with neurological conditions. Despite the paucity of research evidence, the MTS may still remain a clinically useful tool to measure the motor aspect of spasticity. Future research would benefit from a focus on test standardisation, while the wider field would require the development of a consensual definition of spasticity.

Cerebellar Intermittent Theta-Burst Stimulation Reduces Upper Limb Spasticity After Subacute Stroke: A Randomized Controlled Trial

Objective: This study aims to explore the efficacy of cerebellar intermittent theta-burst stimulation (iTBS) on upper limb spasticity in subacute stroke patients.

Methods: A total of 32 patients with upper limb spasticity were enrolled and randomly assigned to treatment with cerebellar iTBS or sham stimulation before conventional physical therapy daily for 2 weeks. The primary outcomes included the modified Ashworth scale (MAS), the modified Tardieu scale (MTS), and the shear wave velocity (SWV). The secondary outcomes were the H-maximum wave/M-maximum wave amplitude ratio (H_max/M_max ratio), motor-evoked potential (MEP) latency and amplitude, central motor conduction time (CMCT), and the Barthel Index (BI). All outcomes were evaluated at baseline and after 10 sessions of intervention.

Results: After the intervention, both groups showed significant improvements in the MAS, MTS, SWV, and BI. In addition, patients treated with cerebellar iTBS had a significant increase in MEP amplitude, and patients treated with sham stimulation had a significant decrease in H_max/M_max ratio. Compared with the sham stimulation group, the MAS, MTS, and SWV decreased more in the cerebellar iTBS group.

Conclusion: Cerebellar iTBS is a promising adjuvant tool to reinforce the therapeutic effect of conventional physical therapy in upper limb spasticity management after subacute stroke (Chinese Clinical Trial Registry: ChiCTR1900026516).

Elucidating factors influencing machine learning algorithm prediction in spasticity assessment: a prospective observational study

The Machine Learning Model (MLM) has garnered popularity in rehabilitation, ranging from developing algorithms in outcome prediction, prognostication, and training artificial intelligence. High-quality data plays a critical role in algorithm development. Limited studies have explored factors that may influence the MLM algorithm performance in predicting spasticity severity level. The objectives of this study were to train and validate a MLM algorithm for spasticity assessment and determine the algorithm's prediction performance in predicting ambiguous spasticity datasets. Forty-seven persons with central nervous system pathology that fulfilled the inclusion and exclusion criteria were recruited. Four biomechanical properties of spasticity were obtained using off-the-shelf wearable sensors. The data were analyzed individually, and ambiguous datasets were separated. The acceptable inertial data were used to train and validate MLM in predicting spasticity. The trained and validated MLM algorithm was later deployed to predict the ambiguous spasticity datasets. A series of MLM were applied, including Support Vector Machine, Decision Tree, and Random Forest. The MLM's performance accuracy of the validation data was 96%, 52%, and 72%, respectively. The validated MLM accuracy performance level predicting ambiguous datasets reduces to 20%, 23%, and 23%, respectively. This study elucidates data biases and variances of disease background, pathophysiological and anatomical factors that have to be considered in MLM training.

Arm activity measure (ArmA): psychometric evaluation of the Swedish version

Background

Patient Reported Outcomes Measure (PROM) are commonly used in research and essential to understand the patient experience when receiving treatment. Arm Activity Measure (ArmA) is a valid and reliable self-report questionnaire for assessing passive (section A) and active (section B) real-life arm function in patients with disabling spasticity. The original English version of ArmA has been psychometrically tested and translated into Thai.

Aims

Translate and cross-culturally adapt ArmA to Swedish language and context. Further, to evaluate the reliability, validity and sensitivity of the Swedish version of the questionnaire (ArmA-S) in patients with disabling upper limb spasticity caused by injuries to the central nervous system (CNS).

Materials and methods

ArmA was translated and cross-culturally adapted according to established guidelines. Validity and reliability were evaluated in 61 patients with disabling spasticity. Face and content validity was evaluated by expert opinions from clinicians and feedback from patients with upper limb spasticity. Internal consistency reliability was assessed with Cronbach’s alpha and test-retest reliability was assessed using the quadratic weighted kappa.

Results

ArmA-S was shown to be clinically feasible, with good face and content validity and no floor or ceiling effects. Internal consistency of ArmA-S was high and equivalent to ArmA; with Chronbach´s alpha coefficients values of 0.94 and 0.93 for section A and B, respectively. Test-retest reliability was good, with kappa values of 0.86 and 0.83 for section A and B, respectively. Some layout modifications of ArmA-S were made to further increase the user-friendliness, test-retest reliability, and responsiveness.

Conclusion

ArmA-S was shown to be a reliable and valid self-report questionnaire for use in clinical practice and research to assess improvements in passive and active upper limb function in patients with disabling spasticity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00310-4.

Quantitative Modeling of Spasticity for Clinical Assessment, Treatment and Rehabilitation

Spasticity, a common symptom in patients with upper motor neuron lesions, reduces the ability of a person to freely move their limbs by generating unwanted reflexes. Spasticity can interfere with rehabilitation programs and cause pain, muscle atrophy and musculoskeletal deformities. Despite its prevalence, it is not commonly understood. Widely used clinical scores are neither accurate nor reliable for spasticity assessment and follow up of treatments. Advancement of wearable sensors, signal processing and robotic platforms have enabled new developments and modeling approaches to better quantify spasticity. In this paper, we review quantitative modeling techniques that have been used for evaluating spasticity. These models generate objective measures to assess spasticity and use different approaches, such as purely mechanical modeling, musculoskeletal and neurological modeling, and threshold control-based modeling. We compare their advantages and limitations and discuss the recommendations for future studies. Finally, we discuss the focus on treatment and rehabilitation and the need for further investigation in those directions.

Introduction of a procedure to objectively quantify spastic movement impairment during freely performed voluntary movements

Spastic impaired limb function is a frequent result of brain lesions. Although its assessment is important for clinical and therapeutical management, it still lacks an objective measure to quantify the functionality of the affected limb. The present paper reports a procedure based on the muscular activation recorded by Surface Electromyography (sEMG), which enables the assessment of the degree of spastic impairment. 15 healthy subjects and 7 patients with impaired upper limb function due to spasticity were included in the study. SEMG was recorded from the biceps and brachioradialis during active elbow extension at different movement velocities. The spastic impairment was clinically assessed by the Tardieu-Test and the Wolf Motor Function Test. Results of the clinical assessment and parameter values quantifying the muscular activation at different joint positions and movement velocities have been set in relation to one another. The results show that spastic impairment leads to a changed correlation between the muscular activation and movement velocity as well as to a changed inter-muscular co-ordination of biceps and brachioradialis. These changes, reflected in the sEMG, can be quantified by 5 newly introduced parameters. This way could allow the assessment of spastic impairment in the context of functional everyday tasks, for the first-time.

A Regression-Based Framework for Quantitative Assessment of Muscle Spasticity Using Combined EMG and Inertial Data From Wearable Sensors

There have always been practical demands for objective and accurate assessment of muscle spasticity beyond its clinical routine. A novel regression-based framework for quantitative assessment of muscle spasticity is proposed in this paper using wearable surface electromyogram (EMG) and inertial sensors combined with a simple examination procedure. Sixteen subjects with elbow flexor or extensor (i.e., biceps brachii muscle or triceps brachii muscle) spasticity and eight healthy subjects were recruited for the study. The EMG and inertial data were recorded from each subject when a series of passive elbow stretches with different stretch velocities were conducted. In the proposed framework, both lambda model and kinematic model were constructed from the recorded data, and biomarkers were extracted respectively from the two models to describe the neurogenic component and biomechanical component of the muscle spasticity, respectively. Subsequently, three evaluation methods using supervised machine learning algorithms including single-/multi-variable linear regression and support vector regression (SVR) were applied to calibrate biomarkers from each single model or combination of two models into evaluation scores. Each of these evaluation scores can be regarded as a prediction of the modified Ashworth scale (MAS) grade for spasticity assessment with the same meaning and clinical interpretation. In order to validate performance of three proposed methods within the framework, a 24-fold leave-one-out cross validation was conducted for all subjects. Both methods with each individual model achieved satisfactory performance, with low mean square error (MSE, 0.14 and 0.47) between the resultant evaluation score and the MAS. By contrast, the method using SVR to fuse biomarkers from both models outperformed other two methods with the lowest MSE at 0.059. The experimental results demonstrated the usability and feasibility of the proposed framework, and it provides an objective, quantitative and convenient solution to spasticity assessment, suitable for clinical, community, and home-based rehabilitation.

Biomechanical parameters of the elbow stretch reflex in chronic hemiparetic stroke

We sought to determine the relative velocity sensitivity of stretch reflex threshold angle and reflex stiffness during stretches of the paretic elbow joint in individuals with chronic hemiparetic stroke, and to provide guidelines to streamline spasticity assessments. We applied ramp-and-hold elbow extension perturbations ranging from 15 to 150°/s over the full range of motion in 13 individuals with hemiparesis. After accounting for the effects of passive mechanical resistance, we modeled velocity-dependent reflex threshold angle and torque-angle slope to determine their correlation with overall resistance to movement. Reflex stiffness exhibited substantially greater velocity sensitivity than threshold angle, accounting for ~ 74% (vs. ~ 15%) of the overall velocity-dependent increases in movement resistance. Reflex stiffness is a sensitive descriptor of the overall velocity-dependence of movement resistance in spasticity. Clinical spasticity assessments can be streamlined using torque-angle slope, a measure of reflex stiffness, as their primary outcome measure, particularly at stretch velocities greater than 100°/s.

A historical review of the evolution of the Tardieu Scale

There are many clinical assessment tools that can be used to quantify spasticity, one feature of the Upper Motor Neurone (UMN) syndrome. The focus of this short paper is on three; the Tardieu Scale, the Modified Tardieu Scale and the Australian Spasticity Assessment Scale, because a fundamental concept of these tests is their velocity dependent nature. Other bedside assessments such as the Modified Ashworth Scale examine hypertonicity, another feature of the UMN syndrome, but in this instance, the stretching movement is not velocity dependent. The Tardieu Scale, while not officially named until 1997, was conceived in the 1950s and since that time it has been revised by multiple authors and it is these additions that will be discussed in this article. The advantages and disadvantages of these assessment tools will be discussed with the ultimate aim of identifying one that has greater clinical utility.

Biomechanical investigation of the modified Tardieu Scale in assessing knee extensor spasticity poststroke

OBJECTIVE

The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke.

METHODS

Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)].

RESULTS

The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was -0.83 (SD 0.73, range -2.6-0.3). There was no significant relationship between the R₂ -R₁ and the slope of work-velocity curve (r = 0.09, p = .62).

CONCLUSIONS

The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.

The Spinal Cord Injury Spasticity Evaluation Tool: A Persian adaptation and validation study

OBJECTIVE

To adapt the Spinal Cord Injury Spasticity Evaluation Tool (SCI-SET) into the Persian language (SCI-SETp) and to examine the reliability and validity of the SCI-SETp in patients with spinal cord injury (SCI).

DESIGN

A cross-sectional and prospective cohort validation study.

SETTING

University Neurological Physiotherapy Clinic.

PARTICIPANTS

Adult patients with SCI.

MAIN OUTCOME MEASURES

SCI-SET.

RESULTS

There was no missing data. No floor or ceiling effect was observed. Cronbach's α coefficient was 0.862. Factor analysis suggested 1 factor structure (Eigenvalue = 8.49) explained 24.27% of the total variance. The ICC_agreement for test-retest reliability was 0.84. The standard error of measurement and the smallest detectable change was 0.30 and 0.82, respectively. The divergent relationships demonstrated the SCI-SETp uniqueness construct.

CONCLUSION

The results support the reliability and validity of the SCI-SETp for assessing the impact of spasticity on daily life of patients with SCI.

Intra-rater reliability of the Modified Tardieu Scale in patients with multiple sclerosis

The reliability of the Modified Tardieu Scale (MTS) has not been examined in patients with multiple sclerosis (MS). This study aimed to assess intra-rater reliability of the MTS in the assessment of lower limb spasticity in patients with MS. Data from 30 patients with MS (18 women, mean age = 41.5) were used to assess intra-rater reliability. An inexperienced physiotherapist in the scale randomly examined the hip adductors, knee extensors, and ankle plantar flexors on each subject twice with at least a 7-day interval. Kappa statistics (κ) were calculated for MTS quality of muscle reactions. Intraclass correlation coefficients (ICC_agreement) and smallest detectable change (SDC) were calculated for R2, R1, and R2-R1. Qualitative rating of spasticity demonstrated moderate or good agreement, with an overall moderate κ of 0.72. Intra-rater reliability for all angle components of MTS was poor to good (ICC_agreement range 0.45-0.83). The SDC for all the MTS components across the muscle groups was unacceptably large (range 14.6-55.6). Results did not establish good intra-rater reliability for the MTS when assessing lower limb muscle spasticity in patients with MS by a physiotherapist with no previous experience in the scale and with limited training.

A single group, pretest-posttest clinical trial for the effects of dry needling on wrist flexors spasticity after stroke

BACKGROUND

Spasticity is a common complication after stroke. Dry needling (DN) is suggested as a novel method for treatment of muscle spasticity.

OBJECTIVE

To explore the effects of DN on wrist flexors spasticity poststroke.

METHODS

A single group, pretest-posttest clinical trial was used. Twenty nine patients with stroke (16 male; mean age 54.3 years) were tested at baseline (T0), immediately after DN (T1), and one hour after DN (T2). DN was applied for flexor carpi radialis (FCR) and flexor carpi ulnaris on the affected arm for single session, one minute per muscle. The Modified Modified Ashworth Scale (MMAS), passive resistance force, wrist active and passive range of motion, Box and Block Test, and FCR H-reflex were outcome measures.

RESULTS

Significant reductions in MMAS scores were seen both immediately after DN and at 1-hour follow-up (median 2 at T0 to 1 at T1 and T2). There were significant improvements in other measures between the baseline values at T0 and those recorded immediately after the DN at T1 or one hour later at T2.

CONCLUSIONS

This study suggests that DN reduced wrist flexors spasticity and alpha motor neuron excitability in patients with stroke, and improvements persisted for one hour after DN.

Hindlimb spasticity after unilateral motor cortex lesion in rats is reduced by contralateral nerve root transfer

Transfer of nerve root from normal side to the spastic side could reduce unilateral motor cortex lesion-induced contralateral hindlimb spasticity in rats.

Lower extremity spasticity is a common sequela among patients with acquired brain injury. The optimum treatment remains controversial. The aim of our study was to test the feasibility and effectiveness of contralateral nerve root transfer in reducing post stroke spasticity of the affected hindlimb muscles in rats. In our study, we for the first time created a novel animal hindlimb spastic hemiplegia model in rats with photothrombotic lesion of unilateral motor cortex and we established a novel surgical procedure in reducing motor cortex lesion-induced hindlimb spastic hemiplegia in rats. Thirty six rats were randomized into three groups. In group A, rats received sham operation. In group B, rats underwent unilateral hindlimb motor cortex lesion. In group C, rats underwent unilateral hindlimb cortex lesion followed by contralateral L4 ventral root transfer to L5 ventral root of the affected side. Footprint analysis, Hoffmann reflex (H-reflex), cholera toxin subunit B (CTB) retrograde tracing of gastrocnemius muscle (GM) motoneurons and immunofluorescent staining of vesicle glutamate transporter 1 (VGLUT1) on CTB-labelled motoneurons were used to assess spasticity of the affected hindlimb. Sixteen weeks postoperatively, toe spread and stride length recovered significantly in group C compared with group B (P<0.001). H_max (H-wave maximum amplitude)/M_max (M-wave maximum amplitude) ratio of gastrocnemius and plantaris muscles (PMs) significantly reduced in group C (P<0.01). Average VGLUT1 positive boutons per CTB-labelled motoneurons significantly reduced in group C (P<0.001). We demonstrated for the first time that contralateral L4 ventral root transfer to L5 ventral root of the affected side was effective in relieving unilateral motor cortex lesion-induced hindlimb spasticity in rats. Our data indicated that this could be an alternative treatment for unilateral lower extremity spasticity after brain injury. Therefore, contralateral neurotization may exert a potential therapeutic candidate to improve the function of lower extremity in patients with spastic hemiplegia.