Efficacy of Botulinum Toxin A Treatment for Pes Varus during Gait

Minimal Detectable Change in Muscle Strength Measurements Obtained Using a Hand-Held Dynamometer in Patients with Stroke

Itoh S, Tanikawa H, Kondo H, Ozeki S, Ito T, Fujimura K, Teranishi T. Minimal Detectable Change in Muscle Strength Measurements Obtained Using a Hand-Held Dynamometer in Patients with Stroke. Jpn J Compr Rehabil Sci 2025; 16: 9-18.

Objective

The current study aimed to evaluate the reliability of muscle strength measurements using a hand-held dynamometer (HHD) in patients with chronic stroke. Further, it examined the minimal detectable change (MDC95).

Methods

Patients who presented with chronic stroke hemiplegia for > 180 days post-stroke onset were analyzed. Muscle strength in the paretic lower limb was assessed using an HHD, and gait speed was evaluated.

Results

For hip flexion, hip adduction, hip abduction, knee extension, ankle dorsiflexion, and ankle plantarflexion, the intra-rater reliability of the muscle strength measurements, as assessed using the intraclass correlation coefficient (ICC), ranged from 0.989 to 0.998. The inter-rater reliability, as assessed using ICC, ranged from 0.886 to 0.939. Bland-Altman analysis did not indicate systematic errors, and the MDC95 of each joint movement was calculated. Muscle strength in hip flexion, hip adduction, knee extension, ankle dorsiflexion, and ankle plantarflexion were significantly associated with gait speed, but not with hip abduction strength. The MDC95 of each muscle strength measurement was established, thereby providing a criterion for detecting actual changes that exceed the measurement error.

Conclusions

The HHD had a high reliability in measuring lower limb muscle strength in patients with chronic stroke hemiplegia. Moreover, an association was found between individual muscle strength and gait ability. Based on this study, specific target muscles for interventions that aim to improve gait speed can be identified. Further, the use of MDC95 allows for a more accurate assessment of the intervention effects.

Gait Reconstruction Strategy Using Botulinum Toxin Therapy Combined with Rehabilitation

Numerous studies have established a robust body of evidence for botulinum toxin A (BoNT-A) therapy as a treatment for upper motor neuron syndrome. These studies demonstrated improvements in spasticity, range of joint motion, and pain reduction. However, there are few studies that have focused on improvement of paralysis or functional enhancement as the primary outcome. This paper discusses the multifaceted aspects of spasticity assessment, administration, and rehabilitation with the goal of optimising the effects of BoNT-A on lower-limb spasticity and achieving functional improvement and gait reconstruction. This paper extracts studies on BoNT-A and rehabilitation for the lower limbs and provides new knowledge obtained from them. From these discussion,, key points in a walking reconstruction strategy through the combined use of BoNT-A and rehabilitation include: (1) injection techniques based on the identification of appropriate muscles through proper evaluation; (2) combined with rehabilitation; (3) effective spasticity control; (4) improvement in ankle joint range of motion; (5) promotion of a forward gait pattern; (6) adjustment of orthotics; and (7) maintenance of the effects through frequent BoNT-A administration. Based on these key points, the degree of muscle fibrosis and preintervention walking speed may serve as indicators for treatment strategies. With the accumulation of recent studies, a study focusing on walking functions is needed. As a result, it is suggested that BoNT-A treatment for lower limb spasticity should be established not just as a treatment for spasticity but also as a therapeutic strategy in the field of neurorehabilitation aimed at improving walking function.

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.

Ankle and Foot Spasticity Patterns in Chronic Stroke Survivors with Abnormal Gait

Chronic stroke survivors with spastic hemiplegia have various clinical presentations of ankle and foot muscle spasticity patterns. They are mechanical consequences of interactions between spasticity and weakness of surrounding muscles during walking. Four common ankle and foot spasticity patterns are described and discussed through sample cases. The patterns discussed are equinus, varus, equinovarus, and striatal toe deformities. Spasticity of the primary muscle(s) for each deformity is identified. However, it is emphasized that clinical presentation depends on the severity of spasticity and weakness of these muscles and their interactions. Careful and thorough clinical assessment of the ankle and foot deformities is needed to determine the primary cause of each deformity. An understanding of common ankle and foot spasticity patterns can help guide clinical assessment and selection of target spastic muscles for botulinum toxin injection or nerve block.

Botulinum Toxin Therapy Combined with Rehabilitation for Stroke: A Systematic Review of Effect on Motor Function

Aim: The purpose of this study was to examine the effectiveness of botulinum toxin A (BoNT-A) therapy combined with rehabilitation on motor function in post-stroke patients. Methods: The following sources up to December 31, 2018, were searched from inception for articles in English: Pubmed, Scopus, CINAHL, Embase, PsycINFO, and CENTRAL. Trials using injections of BoNT-A for upper and lower limb rehabilitation were examined. We excluded studies that were not performed for rehabilitation or were not evaluated for motor function. Results: Twenty-six studies were included. In addition to rehabilitation, nine studies used adjuvant treatment to improve spasticity or improve motor function. In the upper limbs, two of 14 articles indicated that significant improvement in upper limb motor function was observed compared to the control group. In the lower limbs, seven of 14 articles indicated that significant improvement in lower limb motor function was observed compared to the control group. Conclusions: The effect of combined with rehabilitation is limited after stroke, and there is not sufficient evidence, but results suggest that BoNT-A may help to improve motor function. In future studies, the establishment of optimal rehabilitation and evaluation times of BoNT-A treatment will be necessary for improving motor function and spasticity.

The Effect of Repeated Botulinum Toxin A Therapy Combined with Intensive Rehabilitation on Lower Limb Spasticity in Post-Stroke Patients

Objectives: This study is a retrospective investigation of the effects of repetitive botulinum toxin A therapy (BoNT-A) and intensive rehabilitation (IR) on lower limb spasticity in post-stroke patients. Methods: Thirty-five post-stroke patients was included in this study and received BoNT-A for the first time. A 12-day inpatient protocol was with 4 cycles of the treatment protocol. The severity of spasticity, motor function and brace status were evaluated. Results: The modified Ashworth Scale (MAS) score of ankle dorsiflexors, range of motion, walking speed and balancing ability were significantly improved after cycle 1. The improvement of spasticity and motor function was persistent through cycles 2–4. One-third of brace users were able to discontinue the use of a brace. All of these brace users showed a forward gait pattern prior to therapy. Conclusions: Repeated BoNT-A combined with IR improved lower limb spasticity in post-stroke patients. Our results suggest that patients who show the forward gait pattern prior to therapy may be able to discontinue the use of their brace after therapy.

Quantitative assessment for flexed-elbow deformity during gait following botulinum toxin A treatment

BACKGROUND

The effect of botulinum toxin A (BoNTA) injection on flexed-elbow deformity is usually evaluated using the Modified Ashworth Scale (MAS), but only with the muscle tone at rest. Some patients show the flexed-elbow deformity during gait despite low muscle tone at rest.

OBJECTIVE

This study aimed to evaluate the effect of BoNTA injection on flexed-elbow deformity during gait using a three-dimensional motion analysis system.

METHODS

Twenty stroke patients with spastic flexed-elbow deformity during gait received BoNTA injections into the upper limb muscles. The MAS score of the elbow flexors, passive elbow range of motion, comfortable overground gait velocity, and elbow flexion angle during treadmill gait were evaluated just before and 2, 6, and 12 weeks after the injection. Twenty-five healthy subjects were also recruited to provide a normal reference of the elbow flexion angle.

RESULTS

The MAS scores at 2, 6 and 12 weeks after the injection were significantly lower than that before the injection. Some patients showed no spasticity at rest but an obviously flexed elbow during gait. The elbow flexion angles during gait at 2 and 6 weeks after the injection were significantly lower than that before the injection.

CONCLUSIONS

BoNTA injections to the upper limb muscles reduced muscle tone at rest and flexed-elbow deformity during gait. However, the elbow flexion angle during gait returned to its pre-injection level sooner than the muscle tone at rest. We strongly recommend evaluating muscle tone during motion and at rest, preferably using three-dimensional motion analysis since it can objectively detect small changes.

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.