Efficacy and Optimal Dose of Botulinum Toxin A in Post-Stroke Lower Extremity Spasticity: A Systematic Review and Meta-Analysis

Assessment of pain relief after four botulinum toxin A injection cycles in patients with post-stroke lower limb spasticity: A prospective, observational study

INTRODUCTION

Spasticity is common after a stroke and is an independent risk factor for developing pain. BotulinumtoxinA injection is the treatment of choice for focal spasticity. We examined the effect of intramuscular botulinumtoxinA on pain relief in patients in routine clinical practice who were experiencing pain as a primary complaint associated with post-stroke lower limb spasticity.

METHODS

Prospective, multicentre, post-marketing observational study. The study period was 16 months. The primary effectiveness variable was the mean change from baseline on the pain 0-10 Numerical Rating Scale after four botulinumtoxinA injection cycles. Secondary endpoints included changes from baseline on the pain 0-100 Visual Analogue Scale, Goal Attainment Scale, modified Ashworth Scale, 10-Meter Walk Test, Penn Spasm Frequency Scale, and 36-item Short-Form Health Survey.

RESULTS

Of 186 enrolled patients, 180 (96.8%) received botulinumtoxinA at least once. The mean (standard deviation) pain 0-10 Numerical Rating Scale score decreased significantly (p<0.0001) from 4.9 (2.2) at baseline to 2.5 (2.1) at study end, representing a 50% decrease in pain severity. Relief of pain due to spasticity was supported by improvement from baseline in all secondary variables except the 10-Meter Walk Test. Two adverse events (erysipelas and phlebitis) in one patient were considered likely to be related to botulinumtoxinA injection.

CONCLUSION

BotulinumtoxinA appears to provide pain relief as an additional benefit of local treatment in patients with post-stroke lower limb spasticity for whom pain relief is a primary therapeutic goal (a Lay Abstract has been provided as Appendix A).

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

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

Evaluation of therapeutic benefits of botulinum toxin for foot dystonia associated with Parkinson's disease

BACKGROUND

Foot dystonia occurs in patients with Parkinson's disease (PD) and leads to pain, malformation, and difficulty with walking. Botulinum toxin injections may be effective for foot dystonia, but the extent of improvement and effects on motor function are unclear.

METHODS

In this study, we performed botulinum toxin injections for foot dystonia in 25 patients with PD. At 3 weeks and 3 months post-infection, we assessed changes in plantar pressure distribution utilizing the Pressure Plate system; dystonia using the Modified Ashworth Spasm score; pain using the visual analog scale (VAS) score; and lower extremity function using the Calf-raise Senior (CRS) test, Timed Up and Go (TUG) test, and gait parameters (eg, stride length, step length).

RESULTS

We found improved Modified Ashworth Spasm score (p < 0.01) and VAS score (p < 0.01) post-injection. CRS test score (3 weeks, p = 0.006; 3 months, p = 0.068), stride length (3 weeks, p = 0.012; 3 months, p = 0.715), and step length (3 weeks, p = 0.011; 3 months, p = 0.803) also improved. Plantar pressure distribution improved after botulinum toxin injection (metatarsal 1, 3 weeks, p = 0.031; 3 months, p = 0.144; metatarsal 2, 3 weeks, p = 0.049; 3 months, p = 0.065; metatarsal 3, 3 weeks, p = 0.002; 3 months, p = 0.017; metatarsal 4, 3 weeks, p = 0.017; 3 months, p = 0.144; medial heel, 3 weeks, p = 0.01; 3 months, p = 0.395; lateral heel, 3 weeks, p = 0.035; 3 months, p = 0.109).

CONCLUSION

Botulinum toxin injection for foot dystonia in patients with PD can reduce spasms and pain and normalize plantar pressure distribution, which improves balance and lower extremity function.

Management of Upper-Limb Spasticity Using Modern Rehabilitation Techniques versus Botulinum Toxin Injections Following Stroke

Our purpose is to emphasize the role of botulinum toxin in spasticity therapy and functional recovery in patients following strokes. Our retrospective study compared two groups, namely ischemic and hemorrhagic stroke patients. The study group (BT group) comprised 80 patients who received focal botulinum toxin as therapy for an upper limb with spastic muscle three times every three months. The control group (ES group) comprised 80 patients who received only medical rehabilitation consisting of electrostimulation and radial shockwave therapy for the upper limb, which was applied three times every three months. Both groups received the same stretching program for spastic muscles as a home training program. We evaluated the evolution of the patients using muscle strength, Ashworth, Tardieu, Frenchay, and Barthel scales. The analysis indicated a statistically significant difference between the two groups for all scales, with better results for the BT group (p < 0.0001 for all scales). In our study, the age at disease onset was an important prediction factor for better recovery in both groups but not in all scales. Better recovery was obtained for younger patients (in the BT group, MRC scale: rho = -0.609, p-value < 0.0001; Tardieu scale: rho = -0.365, p-value = 0.001; in the ES group, MRC scale: rho = -0.445, p-value < 0.0001; Barthel scale: rho = -0.239, p-value = 0.033). Our results demonstrated the effectiveness of botulinum toxin therapy compared with the rehabilitation method, showing a reduction of the recovery time of the upper limb, as well as an improvement of functionality and a reduction of disability. Although all patients followed a specific kinetic program, important improvements were evident in the botulinum toxin group.

A large travel-associated outbreak of iatrogenic botulism in four European countries following intragastric botulinum neurotoxin injections for weight reduction, Türkiye, February to March 2023

In March 2023, 34 associated cases of iatrogenic botulism were detected in Germany (30 cases), Switzerland (two cases), Austria (one case), and France (one case). An alert was rapidly disseminated via European Union networks and communication platforms (Food- and Waterborne Diseases and Zoonoses Network, EpiPulse, Early Warning and Response System) and the International Health Regulation mechanism; the outbreak was investigated in a European collaboration. We traced sources of the botulism outbreak to treatment of weight loss in Türkiye, involving intragastric injections of botulinum neurotoxin. Cases were traced using a list of patients who had received this treatment. Laboratory investigations of the first 12 German cases confirmed nine cases. The application of innovative and highly sensitive endopeptidase assays was necessary to detect minute traces of botulinum neurotoxin in patient sera. The botulism notification requirement for physicians was essential to detect this outbreak in Germany. The surveillance case definition of botulism should be revisited and inclusion of cases of iatrogenic botulism should be considered as these cases might lack standard laboratory confirmation yet warrant public health action. Any potential risks associated with the use of botulinum neurotoxins in medical procedures need to be carefully balanced with the expected benefits of the procedure.

The Efficacy of Transvaginal Ultrasound-Guided BoNT-A External Sphincter Injection in Female Patients with Underactive Bladder

Owing to the diverse treatment outcomes after a botulinum toxin A (BoNT-A) injection to the external sphincter, this study aimed to develop a new technique: an ultrasound-guided BoNT-A external sphincter injection. This single-center prospective cohort study was conducted at a tertiary medical center in Taichung, Taiwan. From December 2020 to September 2022, 12 women were enrolled. The patients were evaluated for lower urinary tract syndrome using patient perception of bladder condition (PPBC), international prostate symptom score (IPSS), uroflowmetry, post-void residual volume (PVR), cystometry, and external sphincter electromyography. We evaluated the patients the day before surgery and 1 week after the BoNT-A injection. For the patients requiring self-catheterization, we recorded the number of times they required clean intermittent catheterization (CIC) per day before the procedure and 1 month after the procedure. The IPSS, PPBC, and PVR were significantly better after the transvaginal ultrasound-guided BoNT-A external sphincter injection. The number of times the patients required daily CIC was also reduced after the injection. Only one patient developed de novo urge urinary incontinence. Our results demonstrated that a transvaginal ultrasound-guided BoNT-A injection was efficacious and safe in the treatment of underactive bladder.

Treatment outcome of local injection of botulinum toxin for claw toe: Differences between cerebral hemorrhage and infarction

BACKGROUND

Some patients with post-stroke claw toe respond well to botulinum toxin (BoNT) treatment while others do not. This study was designed to assess the impact of stroke type (cerebral hemorrhage and cerebral infarction) on the outcome of BoNT treatment for claw toe.

METHODS

We retrospectively examined the medical records of patients who received local BoNT (onabotulinumtoxin A) injections into the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles. All patients suffered stroke-related leg paralysis and spasticity.

RESULTS

The study participants were 58 patients (mean age, 61.4 ± 10.3 years, ± SD) with time since stroke of 6.7 ± 4.4 years. The stroke type was cerebral hemorrhage (n = 38) and cerebral infarction (n = 20). After a total of 124 BoNT administrations with medical records entries on the subjective symptoms, the odds for symptomatic improvement was approximately 5.8 times higher in patients of the infarction group compared with the hemorrhage group (OR = 5.787, 95% CI = 2.369-14.134, p = 0. 000). Fifty-one patients (32 with cerebral hemorrhage, 19 with cerebral infarction) received the first local BoNT injection and had available medical records, analysis of which showed a significantly higher rate of symptomatic improvement in patients of the infarction group than those of the hemorrhage group (p = 0.006). After adjustment by factors known to influence treatment outcome (degree of spasticity and paralysis, BoNT dosage, and extent of FDL muscle control of toe movements), the treatment effect was predominantly higher in patients with cerebral infarction.

CONCLUSION

The BoNT treatment response was better for claw toes in cerebral infarction patients than in hemorrhage patients, possibly suggesting that claw toe is associated with more severe spasticity in this group of patients.

The Relationship between Pain and Spasticity and Tell-Tale Signs of Pain in Children with Cerebral Palsy

Pain and quality of life are closely interrelated in children with cerebral palsy (CCP). Even though 67% of CCP experience pain, it is overlooked and untreated. In this study, our purpose was two-fold: first, to examine the relationship between pain and spasticity by evaluating the effects of AbobotulinumtoxinA/Dysport (BoNT), and second, to describe the symptoms and location of pain in CCP. The subjects were 22 CCP in at least moderate pain. They were evaluated for spasticity by the modified Ashworth and Tardieu scale and for pain by the r-FLACC and the pediatric pain profile. After one injection of BoNT, the subjects were re-evaluated. We found a significant reduction in pain, but no significant relationship between the reduction of pain and spasticity. We found no association between the dose of BoNT and pain or spasticity. Pain in the lower extremity was located primarily in the hip region. The effect of ultrasound-guided intermuscular injections of BoNT suggests that pain in CCP has an extra-articular component. We found that pain in CCP manifests as specific tell-tale signs and problems in daily living. In conclusion, we found no relationship between pain and spasticity. Signs and manifestations of pain are described in detail. Lower extremity (hip) pain seems to have a soft tissue/extra-articular component.

Spasticity following brain and spinal cord injury: assessment and treatment

PURPOSE OF REVIEW

Spasticity is a common sequela of brain and spinal cord injury and contributes to disability, reduces quality of life, and increases economic burden. Spasticity is still incompletely recognized and undertreated. We will provide an overview of recent published data on the definition, assessment, and prediction, therapeutic advances, with a focus on promising new approaches, and telemedicine applications for spasticity.

RECENT FINDINGS

Two new definitions of spasticity have been recently proposed, but operational criteria should be developed, and test-retest and inter-rater reliability should be explored. Cannabinoids proved to be effective in spasticity in multiple sclerosis, but evidence in other types of spasticity is lacking. Botulinum neurotoxin injection is the first-line therapy for focal spasticity, and recent literature focused on optimizing its efficacy. Several pharmacological, interventional, and nonpharmacological therapeutic approaches for spasticity have been explored but low-quality evidence impedes solid conclusions on their efficacy. The recent COVID-19 pandemic yielded guidelines/recommendations for the use of telemedicine in spasticity.

SUMMARY

Despite the frequency of spasticity, robust diagnostic criteria and reliable assessment scales are required. High-quality studies are needed to support the efficacy of current treatments for spasticity. Future studies should explore telemedicine tools for spasticity assessment and treatment.

Safety and Efficacy of HU-014 in the Treatment of Post-Stroke Upper Limb Spasticity: A Phase I Pilot Study

Botulinum toxin type A (BTX-A) is widely used for treating post-stroke upper limb spasticity. We evaluated the safety and efficacy of HU-014 in treating post-stroke upper limb spasticity. Thirteen patients were administered with HU-014. The primary outcome was safety, including adverse events, vital signs, physical examination, laboratory tests, and antibody formation test. The secondary outcomes were changes in the Modified Ashworth Scale (MAS) score for wrist, elbow, and finger flexor; Disability Assessment Scale (DAS); Investigator's Global Assessment (IGA) and Subject's Global Assessment (SGA); Caregiver Burden Scale (CBS); and Columbia Suicide Severity Rating Scale (C-SSRS) at weeks 4, 8, and 12 from baseline. No notable safety-related issues were reported. MAS and DAS scores were significantly decreased from those at baseline at 4, 8, and 12 weeks (p < 0.05). At weeks 4, 8, and 12, the IGA and SGA scores were 5.85 ± 0.55, 5.69 ± 0.48, and 5.62 ± 0.65 and 5.46 ± 1.20, 5.85 ± 0.38, and 5.77 ± 0.73, respectively. CBS scores decreased at all timepoints and those for cutting fingernails significantly decreased at 8 and 12 weeks compared with baseline (p < 0.05). C-SSRS scores showed that suicidal ideation in all patients was "low" at all timepoints. HU-014 is a safe treatment that can improve post-stroke upper limb spasticity.

Assessment, goal setting, and botulinum neurotoxin a therapy in the management of post-stroke spastic movement disorder: updated perspectives on best practice

INTRODUCTION

Post-stroke spastic movement disorder (PS-SMD) appears up to 20% in the first week following stroke and 40% in the chronic phase. It may create major hurdles to overcome in early stroke rehabilitation and as one relevant factor that reduces quality of life to a major degree in the chronic phase.

AREAS COVERED

In this review, we discuss predictors,early identification, clinical assessments, goal setting, and management in multiprofessional team, including Botulinum neurotoxin A (BoNT-A) injection for early and chronic management of PS-SMD.

EXPERT OPINION

The earlier PS-SMD is recognized and managed, the better the outcome will be. The comprehensive management in the subacute or chronic phase of PS-SMD with BoNT-A injections requires detailed assessment, patient-centered goal setting, technical-guided injection, effective dosing of BoNT-A per site, muscle, and session and timed adjunctive treatment, delivered in a multi-professional team approach in conjunction with physical treatment. Evidence-based data showed BoNT-A injections are safe and effective in managing focal, multifocal, segmental PS-SMD and its complications. If indicated, BoNT-A therapy should be accompanied with adjunctive treatment in adequate time slots. BoNT-A could be added to oral, intrathecal, and surgical treatment in severe multisegmental or generalized PS-SMD to reach patient/caregiver's goals, especially in chronic PS-SMD.

Ultrasonographic Evaluation of Three Approaches for Botulinum Toxin Injection into Tibialis Posterior Muscle in Chronic Stroke Patients with Equinovarus Foot: An Observational Study

Spastic equinovarus (SEV) foot deformity is commonly observed in patients with post-stroke spasticity. Tibialis posterior (TP) is a common target for botulinum toxin type-A (BoNT-A) injection, as a first-line treatment in non-fixed SEV deformity. For this deep muscle, ultrasonographic guidance is crucial to achieving maximum accuracy for the BoNT-A injection. In current clinical practice, there are three approaches to target the TP: an anterior, a posteromedial, and a posterior. To date, previous studies have failed to identify the best approach for needle insertion into TP. To explore the ultrasonographic characteristics of these approaches, we investigated affected and unaffected legs of 25 stroke patients with SEV treated with BoNT-A. We evaluated the qualitative (echo intensity) and quantitative (muscle depth, muscle thickness, overlying muscle, subcutaneous tissue, cross-sectional area) ultrasound characteristics of the three approaches for TP injection. In our sample, we observed significant differences among almost all the parameters of the three approaches, except for the safety window. Moreover, our analysis showed significant differences in cross-sectional area between treated and untreated. Advantages and disadvantages of each approach were investigated. Our findings can thus provide a suitable reference for clinical settings, especially for novice operators.