Botulinum toxin type A in the treatment of lower limb spasticity in children with cerebral palsy

The Role of Botulinum Toxin Type-A in Spasticity: Research Trends from a Bibliometric Analysis

Botulinum toxin type-A (BoNT-A) has emerged as a key therapeutic agent for the management of spasticity. This paper presents a comprehensive bibliometric and visual analysis of research concerning BoNT-A treatment of spasticity to elucidate current trends and future directions in this research area. A search was conducted in the Web of Science database for articles focused on the use of BoNT-A in spasticity published between 2000 and 2022. We extracted various metrics, including counts of publications and contributions from different countries, institutions, authors, and journals. Analytical methods in CiteSpace were employed for the examination of co-citations, collaborations, and the co-occurrence of keywords. Our search yielded 1489 publications. Analysis revealed a consistent annual increase in research output. The United States, United Kingdom, and Italy were the leading contributors. The top institution in this research was Assistance Publique Hopitaux, Paris. The journal containing the highest number of relevant publications was Toxins. Key frequently occurring keywords were 'stroke', 'cerebral palsy', 'adult spasticity', and 'upper extremity'. This study identified 12 clusters of keywords and 15 clusters of co-cited references, indicating the main focus areas and emerging themes in this field. This study comprehensively analyzed and summarized trends in BoNT-A research in the field of spasticity over the past 22 years.

Botulinum Toxin Treatment for Calf Contouring Based on the Study of Combined Injection of Gastrocnemius and Soleus

BACKGROUND

Botulinum toxin is administered to paralyze the gastrocnemius muscle and reduce its size, thereby improving the calf contour and reducing the leg circumference of the calf.

OBJECTIVES

In pursuit of better efficacy, we designed a new injection protocol that targeted both the gastrocnemius and soleus. An algorithm of botulinum toxin injection for calf contouring was proposed based on the results of the study and ultrasonographic data.

METHODS

A prospective, self-controlled, double-blind study was conducted. The gastronemius muscle (GM) group (n = 17) included the patients whose gastrocnemius muscles were treated, and the GM + soleus muscle (SM) group (n = 17) included the patients who had both the gastrocnemius and soleus treated. Parameters including the maximum leg circumference and the subcutaneous fat, gastrocnemius muscle, and soleus muscle thicknesses were collected before and after injection.

RESULTS

Both GM and GM + SM injection helped improve calf contour. Although the thickness of the gastrocnemius muscle was reduced, reducing the leg circumference, the subcutaneous fat and soleus muscle had compensatory thickening after injection, especially over the long term, which may affect the efficacy. Compared with the GM group, the GM + SM group effectively reduced the tendency of the soleus muscle to thicken. Calf muscle thickness could be roughly estimated by constructing a fitting equation and measuring height, weight, and leg circumference.

CONCLUSIONS

Two injection methods achieved the effect of improving calf contour and reducing the leg circumference with equivalent patient satisfaction. The GM + SM injection group did not show any obvious extra clinical benefit when compared with the GM injection group.

LEVEL OF EVIDENCE: 2

Strategies for addressing the needs of children with or at risk of developmental disabilities in early childhood by 2030: a systematic umbrella review

BACKGROUND

There are over 53million children worldwide under five with developmental disabilities who require effective interventions to support their health and well-being. However, challenges in delivering interventions persist due to various barriers, particularly in low-income and middle-income countries.

METHODS

We conducted a global systematic umbrella review to assess the evidence on prevention, early detection and rehabilitation interventions for child functioning outcomes related to developmental disabilities in children under 5 years. We focused on prevalent disabilities worldwide and identified evidence-based interventions. We searched Medline, Embase, PsychINFO, and Cochrane Library for relevant literature from 1st January 2013 to 14th April 2023. A narrative synthesis approach was used to summarise the findings of the included meta-analyses. The results were presented descriptively, including study characteristics, interventions assessed, and outcomes reported. Further, as part of a secondary analysis, we presented the global prevalence of each disability in 2019 from the Global Burden of Disease study, identified the regions with the highest burden and the top ten affected countries. This study is registered with PROSPERO, number CRD42023420099.

RESULTS

We included 18 reviews from 883 citations, which included 1,273,444 children under five with or at risk of developmental disabilities from 251 studies across 30 countries. The conditions with adequate data were cerebral palsy, hearing loss, cognitive impairment, autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder. ASD was the most prevalent target disability (n = 8 reviews, 44%). Most reviews (n = 12, 67%) evaluated early interventions to support behavioural functioning and motor impairment. Only 33% (n = 10/30) of studies in the reviews were from middle-income countries, with no studies from low-income countries. Regarding quality, half of reviews were scored as high confidence (n = 9/18, 50%), seven as moderate (39%) and two (11%) as low.

CONCLUSIONS

We identified geographical and disability-related inequities. There is a lack of evidence from outside high-income settings. The study underscores gaps in evidence concerning prevention, identification and intervention, revealing a stark mismatch between the available evidence base and the regions experiencing the highest prevalence rates of developmental disabilities.

Botulinum Toxin for the Management of Pelvic Floor Tension Myalgia and Persistent Pelvic Pain: A Systematic Review and Meta-analysis

OBJECTIVE

To systematically review the literature on use of botulinum toxin to treat pelvic floor tension myalgia and persistent pelvic pain.

DATA SOURCES

The ClinicalTrials.gov , PubMed, EMBASE, and Scopus databases were searched from inception to November 2022 by two independent assessors (B.L.K. and F.G.L.). Identified studies were screened by title and abstract and included after full-text review. Data extraction was subsequently performed and recorded in Microsoft Excel.

METHODS

This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines after registration in PROSPERO (CRD42022289132). All randomized studies, prospective studies with more than five participants, and retrospective studies with more than 10 participants published in English or French and assessing the use of botulinum toxin for the treatment of pelvic floor tension myalgia and persistent pelvic pain in women were included. Meta-analyses were performed on randomized data.

TABULATION, INTEGRATION, AND RESULTS

Of 4,722 articles identified, 24 satisfied inclusion criteria. A meta-analysis of five randomized controlled trials totaling 329 participants demonstrated no differences in patient- and clinician-reported outcome measures, including pain, dyspareunia, sexual function, and vaginal manometry. Mean duration of follow-up was 6 months. A qualitative analysis of 14 prospective and four retrospective studies including 804 participants is supportive of botulinum toxin; however, the quality of data is low, and there is marked heterogeneity between studies.

CONCLUSION

Meta-analyses of randomized data do not support the use of botulinum toxin to treat pelvic floor tension myalgia and persistent pelvic pain. Failure of these data to confirm the findings of nonrandomized prospective studies that suggest a treatment benefit may be attributable to the absence of placebo control and confounding outcomes obtained from an active comparator group. Further randomized controlled trials with true placebo are strongly recommended.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022289132.

Evidence-based management and motor rehabilitation of cerebral palsy children and adolescents: a systematic review

Background

Evidence regarding the management of several aspects of cerebral palsy improved in recent years. Still, discrepancies are reported in clinical practice. Italian professionals and stakeholders expressed the need of setting up updated, evidenced-based, shared statements, to address clinical practice in cerebral palsy rehabilitation. The objective of the present study was to provide an updated overview of the state of knowledge, regarding the management and motor rehabilitation of children and young people with cerebral palsy, as the framework to develop evidence-based recommendations on this topic.

Methods

Guidelines and systematic reviews were searched, relative to evidence-based management and motor treatment, aimed at improving gross motor and manual function and activities, in subjects with cerebral palsy, aged 2-18 years. A systematic search according to the Patients Intervention Control Outcome framework was executed on multiple sites. Independent evaluators provided selection and quality assessment of the studies and extraction of data.

Results

Four guidelines, 43 systematic reviews, and three primary studies were included. Agreement among guidelines was reported relative to the general requirements of management and motor treatment. Considering the subject's multidimensional profile, age and developmentally appropriate activities were recommended to set individual goals and interventions. Only a few approaches were supported by high-level evidence (i.e., bimanual therapy and constraint-induced movement therapy to enhance manual performance). Several task-specific active approaches, to improve gross motor function and gait, were reported (mobility and gait training, cycling, backward gait, and treadmill), based on low-level evidence. Increasing daily physical activity and countering sedentary behavior were advised. Based on the available evidence, non-invasive brain stimulation, virtual reality, action-observation therapy, hydrotherapy, and hippotherapy might be complementary to task or goal-oriented physical therapy programs.

Conclusion

A multiple-disciplinary family-centered evidence-based management is recommended. All motor rehabilitation approaches to minors affected by cerebral palsy must share the following fundamental characteristics: engaging active involvement of the subject, individualized, age and developmentally appropriate, goal-directed, skill-based, and preferably intensive and time-limited, but suitable for the needs and preferences of the child or young person and their family, and feasible considering the implications for themselves and possible contextual limitations.

How does treadmill training contribute to botulinum toxin application plus routine physical therapy in ambulatory children with spastic bilateral cerebral palsy? A randomized controlled trial

BACKGROUND

In spite of treadmill training and multilevel botulinum toxin (BoNT-A) injection being the two most commonly used treatment methods in pediatric rehabilitation management, there was no study investigating the effect of treadmill training after BoNT-A injection in children with cerebral palsy (CP).

AIM

The aim of this study was to investigate the effect of treadmill training in addition to routine physical therapy after BoNT-A injection in ambulatory children with spastic bilateral CP on lower extremity muscle strength, selective motor control, and mobility.

METHODS

A total of 30 spastic bilateral children with CP classified level II-III by the Gross Motor Function Classification System were randomly assigned the study and control groups. Both groups continued routine physical therapy treatments after multilevel BoNT-A injection into lower extremities, while the study group additionally underwent 8 weeks of treadmill training (20 min, two sessions per week). Handheld dynamometer, selective control assessment of lower extremity, temporospatial evaluation of gait, and Pediatric Evaluation of Disability Inventory were assessed before and after 8 weeks.

RESULTS

In both groups, hip, knee, and ankle muscle strength increased at the end of 8 weeks (p < 0.05); however, in the study group, hip flexor/extensor muscle strength (p < 0.05, ES ≥ 0.50), selective motor control of ankle (p < 0.01, ES = 1.17), walking speed (p < 0.01, ES = 2.60), step lengths (p < 0.01, ES = 1.32), and mobility (p < 0.01, ES = 1.37) increased significantly compared to those of the control group.

CONCLUSIONS

Treadmill training in addition to routine physical therapy after BoNT-A injection is beneficial for hip muscle strength, ankle selective motor control, walking quality, and functional mobility in the short term.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03580174.

Time-matched accelerometers on limbs and waist in children with CP give new insights into real-life activities after botulinum toxin treatment: A proof of concept study

PURPOSE

This study aimed to explore the feasibility of using time-matched uniaxial accelerometers for measuring movement in daily life in children with cerebral palsy (CP) before and after botulinum toxin injections.

METHODS

This observational study of clinical care with a pre-post design was set in the home and school environment. Participants included eleven children (4-13 years of age) with CP (GMFCS I-III). The children wore uniaxial accelerometers (ActiGraph, model GT1M) for 4 days on both wrists, the right ankle and around the waist before, 3 weeks and 3 months after BoNT-A injections in the legs. Five children also got BoNT-A in the most affected arm. All injections were given according to clinical indications and routine. The accelerometers were all time-matched to define ambulation, arm swing, voluntary activity of arms, and bimanual activity. The feasibility of wearing accelerometers with this setup was evaluated. A linear mixed model was used for analysis of the percentage time and at which intensity the different activities were performed. The confidence interval demonstrated any difference between the dominant and non-dominant arm.

RESULTS

Time-matching of accelerometers placed on both wrists, the waist, and one ankle is a feasible method of registering ambulation, arm swing during gait, and arm movements while not ambulating. Before injections, the children spent 5.6% of their time ambulating. This value declined to 3.9% at 3 months. Contrary to clinical goals, arm movement did not increase after injecting the most affected arm with BoNT-A, however, injections may have decreased mirror movements, which are often bothersome for the child.

CONCLUSION

A time-matched 4-accelerometer set-up is feasible in children with cerebral palsy. A future study including time-matched multi-axial accelerometers on all four limbs, could provide important information on the effect of BoNT-A in daily life.

The Light Chain Domain and Especially the C-Terminus of Receptor-Binding Domain of the Botulinum Neurotoxin (BoNT) Are the Hotspots for Amino Acid Variability and Toxin Type Diversity

Botulinum neurotoxins (BoNT) are the most potent toxins in the world. They are produced by a few dozens of strains within several clostridial species. The toxin that they produce can cause botulism, a flaccid paralysis in humans and other animals. With seven established serologically different types and over 40 subtypes, BoNTs are among the most diverse known toxins. The toxin, its structure, its function and its physiological effects on the neural cell and animal hosts along with its diversity have been the subjects of numerous studies. However, many gaps remain in our knowledge about the BoNT toxin and the species that produce them. One of these gaps involves the distribution and extent of variability along the full length of the gene and the protein as well as its domains and subdomains. In this study, we performed an extensive analysis of all of the available 143 unique BoNT-encoding genes and their products, and we investigated their diversity and evolution. Our results indicate that while the nucleotide variability is almost uniformly distributed along the entire length of the gene, the amino acid variability is not. We found that most of the differences were concentrated along the protein's light chain (LC) domain and especially, the C-terminus of the receptor-binding domain (H_CC). These two regions of the protein are thus identified as the main source of the toxin type differentiation, and consequently, this toxin's versatility to bind different receptors and their isoforms and act upon different substrates, thus infecting different hosts.

The Short-Term Impact of Botulinum Neurotoxin-A on Muscle Morphology and Gait in Children with Spastic Cerebral Palsy

Children with spastic cerebral palsy (SCP) are often treated with intramuscular Botulinum Neurotoxin type-A (BoNT-A). Recent studies demonstrated BoNT-A-induced muscle atrophy and variable effects on gait pathology. This group-matched controlled study in children with SCP compared changes in muscle morphology 8-10 weeks post-BoNT-A treatment (n = 25, median age 6.4 years, GMFCS level I/II/III (14/9/2)) to morphological changes of an untreated control group (n = 20, median age 7.6 years, GMFCS level I/II/III (14/5/1)). Additionally, the effects on gait and spasticity were assessed in all treated children and a subgroup (n = 14), respectively. BoNT-A treatment was applied following an established integrated approach. Gastrocnemius and semitendinosus volume and echogenicity intensity were assessed by 3D-freehand ultrasound, spasticity was quantified through electromyography during passive muscle stretches at different velocities. Ankle and knee kinematics were evaluated by 3D-gait analysis. Medial gastrocnemius (p = 0.018, -5.2%) and semitendinosus muscle volume (p = 0.030, -16.2%) reduced post-BoNT-A, but not in the untreated control group, while echogenicity intensity did not change. Spasticity reduced and ankle gait kinematics significantly improved, combined with limited effects on knee kinematics. This study demonstrated that BoNT-A reduces spasticity and partly improves pathological gait but reduces muscle volume 8-10 weeks post-injections. Close post-BoNT-A follow-up and well-considered treatment selection is advised before BoNT-A application in SCP.

Muscle architecture, growth, and biological Remodelling in cerebral palsy: a narrative review

Cerebral palsy (CP) is caused by a static lesion to the brain occurring in utero or up to the first 2 years of life; it often manifests as musculoskeletal impairments and movement disorders including spasticity and contractures. Variable manifestation of the pathology across individuals, coupled with differing mechanics and treatments, leads to a heterogeneous collection of clinical phenotypes that affect muscles and individuals differently. Growth of muscles in CP deviates from typical development, evident as early as 15 months of age. Muscles in CP may be reduced in volume by as much as 40%, may be shorter in length, present longer tendons, and may have fewer sarcomeres in series that are overstretched compared to typical. Macroscale and functional deficits are likely mediated by dysfunction at the cellular level, which manifests as impaired growth. Within muscle fibres, satellite cells are decreased by as much as 40–70% and the regenerative capacity of remaining satellite cells appears compromised. Impaired muscle regeneration in CP is coupled with extracellular matrix expansion and increased pro-inflammatory gene expression; resultant muscles are smaller, stiffer, and weaker than typical muscle. These differences may contribute to individuals with CP participating in less physical activity, thus decreasing opportunities for mechanical loading, commencing a vicious cycle of muscle disuse and secondary sarcopenia. This narrative review describes the effects of CP on skeletal muscles encompassing substantive changes from whole muscle function to cell-level effects and the effects of common treatments. We discuss growth and mechanics of skeletal muscles in CP and propose areas where future work is needed to understand these interactions, particularly the link between neural insult and cell-level manifestation of CP.

Gait Rehabilitation in Ambulant Diplegic Children Using Botulinum A Injection and Ankle Weights

OBJECTIVES

Standing and walking serve an individual's basic needs to move from place to place, and both are the most common activities that people do daily. So, this study aims to investigate the combined effect of botulinum A injection and ankle weight on excessive knee flexion in diplegic children with crouch gait.

METHODS

Sixty children with spastic diplegia walking with a crouch gait were included in this study. They were divided equally into three groups (twenty in each): group A received classical gait rehabilitation, group B received the same gait training while adding ankle weights, and group C received the same as group A and B plus botulinum A injection. The modified Ashworth scale (MAS) and Hoffman reflex/Myogenic response (H/M ratio) were used to evaluate the spasticity of the hamstring and gastrocnemius muscles, while two-dimension gait analysis was used to record knee flexion angles during gait. The assessment was held one day before starting the treatment and after completing three months of the treatment program.

RESULTS

There was no significant difference between groups before treatment regarding all measured variables. group A revealed a statistically nonsignificant improvement after treatment. Patients in group B showed significant improvement after treatment for both knees regarding the H/M ratio and MAS, which was reflected in the right and left knee range of motion at initial contact (P values 0.030 and 0.001, respectively) and midstance (P values 0.030 and 0.006, respectively). However, more significant improvement was detected regarding all studied variables in both knees after treatment in group C patients with a P value <0.001.

CONCLUSION

The combination of botulinum A injection and ankle weights was more effective in controlling excessive knee flexion in diplegic children with a crouch gait.

Comprehensive rehabilitation of patients with movement disorders with spastic forms of cerebral palsy

Until now, there is no radical method of treating children with cerebral palsy, which allows us to consider scientific research in this direction reasonable and promising.The aim of the research: to study the effect of exercises on the mini-simulator “Kinesioplatform-swing” with biofeedback on the indicators of motor skills in children with spastic cerebral palsy.Materials and methods. We conducted an open, non-randomized, prospective, comparative, controlled study in pairs (each participant in the main group corresponds to a participant in the control group). The study involved 53 patients aged 4–12 years with cerebral palsy: the intervention group (group 1: n = 27 (13 boys, 14 girls)) and the control group (group 2: n = 26 (11 boys, 15 girls)), comparable in terms of gender, age and severity of movement disorders. Characteristics of the medical intervention: group 1 – botulinum toxin type A (BTA, for exercising against the background of relative muscular normotonus) + exercise therapy + exercises on the mini-simulator “Kinesioplatform-swing” with biofeedback (BFB); group 2 – BTA + exercise therapy. Duration of the study: 2019–2020. The difference between groups in terms of motor skills on the day of hospitalization and after completion of the training program (10 sessions each) was determined. Motor skills were assessed according to the GMFM-66/88 (Gross Motor Function Measure) table using the “Scales for measuring global motor functions”.Results. The inclusion of additional exercises on the mini-simulator “Kinesioplatformswing” with biofeedback in the rehabilitation of patients with movement disorders with spastic cerebral palsy (BTA + exercise therapy) in comparison with the control group. However, the question of the long-term effects of such training remains open and requires further study.

Botulinum Toxin A Injection and Perianesthesia Neuromuscular Monitoring: Case Report and Review

The popularity of looking younger has been facilitated by the availability of botulinum toxin (BoNT) injection. In 2019, over 7.7 million injections of BoNT occurred, making it the number one minimally invasive cosmetic procedure in the United States. With the ease of patients obtaining BoNT in an outpatient setting, coupled with the fact that it is considered a minimally invasive procedure, most patients do not disclose the use of BoNT during the preoperative anesthesia evaluation. This case report involves a female whose recent BoNT injections interfered with neuromuscular (NM) monitoring during anesthesia. Neuromuscular monitoring was performed using the orbicularis oculi muscle with repeated train-of-four (TOF) 0/4. It was not until completion of procedure when the arms were accessible that the adductor pollicis muscle was assessed with a TOF of 2/4. During postoperative follow up, the patient revealed she had received BoNT injections prior to surgery. A review of BoNT pharmacology, barriers to NM monitoring and use of sugammadex are discussed. This case demonstrates the importance of ascertaining BoNT injection history in any case in which access to the ulnar nerve or tibial nerve is not available.

The Effects of Preterm Birth on Musculoskeletal Health-Related Disorders

Preterm birth is associated with various diseases and conditions which demand multidisciplinary medical care. Approximately 10% of all neonates are born prematurely with an increasing survival rate in almost all Western countries. This ongoing, yet desirable trend is creating new challenges for sufficient medical treatment regimens, which should be upheld throughout the patients' lives. Orthopedic surgeons are focused on musculoskeletal disorders and the improvement of patients' ability to cope with the challenges of everyday life. The most common conditions associated with preterm birth are cerebral palsy and a dysregulation of the calcium/phosphorus metabolism, which may lead to fractures. These diseases may vary greatly in their organic manifestation and clinical presentation. This demands multidisciplinary cooperation and parental support. Clinical management is aimed on the early enhancement of a patient's physical, as well as neurological condition, and to prevent the development of secondary musculoskeletal disorders. In this article, we give an overview of the current literature on the most common musculoskeletal disorders associated with preterm birth and critically discuss state of the art diagnostic standards and treatment algorithms.

Functional assessment of stretch hyperreflexia in children with cerebral palsy using treadmill perturbations

BACKGROUND

As hyperactive muscle stretch reflexes hinder movement in patients with central nervous system disorders, they are a common target of treatment. To improve treatment evaluation, hyperactive reflexes should be assessed during activities as walking rather than passively. This study systematically explores the feasibility, reliability and validity of sudden treadmill perturbations to evoke and quantify calf muscle stretch reflexes during walking in children with neurological disorders.

METHODS

We performed an observational cross-sectional study including 24 children with cerebral palsy (CP; 6-16 years) and 14 typically developing children (TD; 6-15 years). Short belt accelerations were applied at three different intensities while children walked at comfortable speed. Lower leg kinematics, musculo-tendon lengthening and velocity, muscle activity and spatiotemporal parameters were measured to analyze perturbation responses.

RESULTS

We first demonstrated protocol feasibility: the protocol was completed by all but three children who ceased participation due to fatigue. All remaining children were able to maintain their gait pattern during perturbation trials without anticipatory adaptations in ankle kinematics, spatiotemporal parameters and muscle activity. Second, we showed the protocol's reliability: there was no systematic change in muscle response over time (P = 0.21-0.54) and a bootstrapping procedure indicated sufficient number of perturbations, as the last perturbation repetition only reduced variability by ~ 2%. Third, we evaluated construct validity by showing that responses comply with neurophysiological criteria for stretch reflexes: perturbations superimposed calf muscle lengthening (P < 0.001 for both CP and TD) in all but one participant. This elicited increased calf muscle activity (359 ± 190% for CP and 231 ± 68% for TD, both P < 0.001) in the gastrocnemius medialis muscle, which increased with perturbation intensity (P < 0.001), according to the velocity-dependent nature of stretch reflexes. Finally, construct validity was shown from a clinical perspective: stretch reflexes were 1.7 times higher for CP than TD for the gastrocnemius medialis muscle (P = 0.017).

CONCLUSIONS

The feasibility and reliability of the protocol, as well as the construct validity-shown by the exaggerated velocity-dependent nature of the measured responses-strongly support the use of treadmill perturbations to quantify stretch hyperreflexia during gait. We therefore provided a framework which can be used to inform clinical decision making and treatment evaluation.

Consensus recommendations for botulinum toxin injections in the spasticity management of children with cerebral palsy during COVID-19 outbreak

Spasticity is the most common motor disturbance in cerebral palsy (CP). Lockdown in the COVID-19 outbreak has profoundly changed daily routines, and similarly caused the suspension of spasticity treatment plans. Besides, the delay in botulinum toxin (BoNT) injection, which is important in the management of focal spasticity, led to some problems in children. This consensus report includes BoNT injection recommendations in the management of spasticity during the COVID-19 pandemic in children with CP. In order to develop the consensus report, physical medicine and rehabilitation (PMR) specialists experienced in the field of pediatric rehabilitation and BoNT injections were invited by Pediatric Rehabilitation Association. Items were prepared and adapted to the Delphi technique by PMR specialists. Then they were asked to the physicians experienced in BoNT injections (PMR specialist, pediatric orthopedists, and pediatric neurologists) or COVID-19 (pediatric infectious disease, adult infectious disease). In conclusion, the experts agree that conservative management approaches for spasticity may be the initial steps before BoNT injections. BoNT injections can be administered to children with CP with appropriate indications and with necessary precautions during the pandemic.

Protocol for The Toxin Study: Understanding clinical and patient reported response of children and young people with cerebral palsy to intramuscular lower limb Botulinum neurotoxin-A injections, exploring all domains of the ICF. A pragmatic longitudinal observational study using a prospective one-group repeated measures design

INTRODUCTION

Botulinum neurotoxin-A (BoNT-A) is an accepted treatment modality for the management of hypertonia in children and young people with cerebral palsy (CYPwCP). Nevertheless, there are concerns about the long-term effects of BoNT-A, with a lack of consensus regarding the most meaningful outcome measures to guide its use. Most evidence to date is based on short-term outcomes, related to changes at impairment level (restrictions of body functions and structures), rather than changes in adaptive skills (enabling both activity and participation). The proposed study aims to evaluate clinical and patient reported outcomes in ambulant CYPwCP receiving lower limb BoNT-A injections over a 12-month period within all domains of the WHO's International Classification of Functioning, Disability and Health and health-related quality of life (HRQoL).

METHODS AND ANALYSIS

This pragmatic prospective longitudinal observational study will use a one-group repeated measures design. Sixty CYPwCP, classified as Gross Motor Function Classification System (GMFCS) levels I-III, aged between 4 and 18 years, will be recruited from an established movement disorder service in London, UK. Standardised clinical and patient reported outcome measures within all ICF domains; body structures and function, activity (including quality of movement), goal attainment, participation and HRQoL, will be collected preinjection and at 6 weeks, 6 months and up to 12 months postinjection. A representative subgroup of children and carers will participate in a qualitative component of the study, exploring how their experience of BoNT-A treatment relates to clinical outcome measures.

ETHICS AND DISSEMINATION

Central London Research Ethics Committee has granted ethics approval (#IRAS 211617 #REC 17/LO/0579). Findings will be disseminated in peer-reviewed publications, conferences and via networks to participants and relevant stakeholders using a variety of accessible formats including social media.

Interventional Approaches to Pain and Spasticity Related to Cerebral Palsy

Purpose of Review

This review will cover seminal and emerging evidence on interventional therapy chronic pain in cerebral palsy (CP). It will cover the background and burden of disease, present the current options, and then weigh the evidence that is available to support interventional therapy and the current indications.

Recent Findings

CP is a permanent posture and movement disorder from in-utero brain development defects with a 3-4/1,000 incidence in the US. The cost of care for each child is estimated at $921,000. Pain in CP is attributed to musculoskeletal deformities, spasticity, increased muscle tone, dislocations, and GI dysfunction. First-line treatments include physical and occupational therapy and oral pharmacological agents; however, a significant amount of patients remain refractory to these and require further therapy. Injection therapy includes botulinum toxin A (BTA) injections and intrathecal baclofen. BTA injections were shown to control chronic pain effectively and are FDA approved for spastic pain; intra-thecal baclofen, in contrast, was only shown to improve comfort and quality of life with a focus on the pain. Surgical intervention includes selection dorsal rhizotomy (SDR). It may increase range of motion and quality of life and reduce spasticity and pain; however, most evidence is anecdotal, and more research is required.

Summary

Interventional therapy, including injection and surgical, is the last line of therapy for chronic pain in CP. It extends the possibility of therapy in hard-to-treat individuals; however, more data is required to provide strong evidence to the efficacy of these treatments and guide proper patient selection.

Over 25 Years of Pediatric Botulinum Toxin Treatments: What Have We Learned from Injection Techniques, Doses, Dilutions, and Recovery of Repeated Injections?

Botulinum toxin type A (BTXA) has been used for over 25 years in the management of pediatric lower and upper limb hypertonia, with the first reports in 1993. The most common indication is the injection of the triceps surae muscle for the correction of spastic equinus gait in children with cerebral palsy. The upper limb injection goals include improvements in function, better positioning of the arm, and facilitating the ease of care. Neurotoxin type A is the most widely used serotype in the pediatric population. After being injected into muscle, the release of acetylcholine at cholinergic nerve endings is blocked, and a temporary denervation and atrophy ensues. Targeting the correct muscle close to the neuromuscular junctions is considered essential and localization techniques have developed over time. However, each technique has its own limitations. The role of BTXA is flexible, but limited by the temporary mode of action as a focal spasticity treatment and the restrictions on the total dose deliverable per visit. As a mode of treatment, repeated BTXA injections are needed. This literature reviewed BTXA injection techniques, doses and dilutions, the recovery of muscles and the impact of repeated injections, with a focus on the pediatric population. Suggestions for future studies are also discussed.

IncobotulinumtoxinA for the treatment of spasticity in children with cerebral palsy - a retrospective case series focusing on dosing and tolerability

BACKGROUND

IncobotulinumtoxinA (Xeomin®) is a botulinum neurotoxin type A with established efficacy in the treatment of upper-limb spasticity in adults. This retrospective case series in a university hospital setting aimed to elucidate the safety and tolerability of incobotulinumtoxinA for treatment of spasticity in children with cerebral palsy.

METHODS

Participants received incobotulinumtoxinA injections up to a maximum total dose of 600 U, 24 U/kg body weight. Medical records were reviewed for key demographic information, incobotulinumtoxinA exposure, and adverse effects (AEs).

RESULTS

Sixty-nine children were included (mean age [SD], 8.3 [3.9] years; 44/69 [63.8%] male). One-hundred-and-ninety-one injections were administered, with mean (SD) of 2.8 (1.5) treatment cycles/participant and dosing interval of 6.0 (1.7) months. The number of muscles injected increased from 2.4 (1.2) at cycle 1 to 4.2 (1.9) at cycle 6. The mean (SD) total incobotulinumtoxinA dose increased from 191.7 (126.2) U, (8.5 [5.4] U/kg body weight) at cycle 1 to 368.0 (170.1) U, (9.9 [5.5] U/kg body weight) at cycle 6. Seventy four adverse effects (37.5% of injections) were reported, the most frequent was injection pain (93.2% of AEs). Only three AEs were considered directly treatment-related by injectors: muscle weakness, generalized weakness, and fever.

CONCLUSIONS

Our clinical experience indicates that incobotulinumtoxinA is a well-tolerated treatment option for focal spasticity in children with cerebral palsy.

TRIAL REGISTRATION

As the study was observational and retrospective, no EudraCT registration number was requested. The internal code assigned to the study in the administrative resolution was: 1143-N-15.

Botulinum Toxin Type A Injections Impact Hamstring Muscles and Gait Parameters in Children with Flexed Knee Gait

The aim of this study was to determine if botulinum toxin type A (BoNT-A) injection into the medial hamstring can improve gait kinematics and muscle-tendon length in spastic cerebral palsy (CP) with a flexed knee gait (FKG). Twenty-nine children with spastic CP (Gross Motor Function Classification System I–III) with FKG were recruited for this prospective study. BoNT-A was injected into the semitendinosus and semimembranosus (SM) muscles under ultrasonography guidance. Assessments included Gross Motor Function Measure (GMFM), Modified Ashworth Scale (MAS), Modified Tardieu Scale (MTS), 3-dimensional computerized gait analysis, calculated SM muscle-tendon length and lengthening velocity during gait using musculoskeletal modeling at baseline, 4 and 16 weeks after the injection. Compared to baseline data, significant improvements in GMFM, MAS, and MTS were demonstrated at weeks 4 and 16, and also a significant increase in maximum knee extension during the stance phase was observed at week 4. In addition, the mean lengthening velocity during the swing phase was increased at week 16 without a change in the SM muscle length. Furthermore, there was a significant increase in anterior pelvic tilt at week 4, compared to baseline data. The significant decrease in hip internal rotation after injection was observed only in children with excessive hip internal rotation at initial contact before injection. BoNT-A injection into hamstrings leads to a significant increase in knee extension and anterior pelvic tilt with an increase in lengthening velocity of SM in spastic CP with FKG.

Facts and de facto treatment of spasticity

Recent studies have generally shown favorable outcomes for the use of botulinum toxin (BoNT) injections for the treatment of lower extremity spasticity in children with cerebral palsy. The randomized controlled trials and placebo trials are well described although even those and other studies show high variability in methodology for use of BoNT. This raises questions about which strategies are the most effective. In order to hone the technique, the aim of this review is to discuss these specific parameters: toxin type, dosing, series of injections, localization method, age, number of muscles, and troubleshooting poor outcomes.