Severity of cerebral palsy and likelihood of adverse events after botulinum toxin A injections

Proteomic changes of botulinum neurotoxin injection on muscle growth in children with spastic cerebral palsy

PURPOSE

The study aims to explore the proteomic profile and specific target proteins associated with muscle growth in response to botulinum neurotoxin A (BoNT-A) treatment, in order to improve spasticity management in children with cerebral palsy (CP).

EXPERIMENTAL DESIGN

A total of 54 participants provided 60 plasma samples for proteomic analysis. Among them, six children were sampled before and after receiving their first BoNT-A injection. In addition, 48 unrelated children were enrolled, among whom one group had never received BoNT-A injections and another group was sampled after their first BoNT-A injection. Differentially expressed proteins were identified using the data-independent acquisition (DIA) mass spectrometry approach. Gene Ontology (GO), protein-protein interaction network, and Kyoto Encyclopedia of Genes and Genome analysis were conducted to explore the function and relationship among differentially expressed proteins. The expression levels of target proteins were verified by quantitative real-time PCR and western blotting.

RESULTS

Analysis identified significant differential expression of 90 proteins across two time points, including 48 upregulated and 42 downregulated proteins. The upregulated thioredoxin, α-actinin-1, and aggrecan, and the downregulated integrin beta-1 may affect the growth of muscles affected by spasticity 3 months after BoNT-A injection. This effect is potentially mediated through the activation or inhibition of PI3K-Akt, focal adhesion, and regulation of actin cytoskeleton signaling pathways.

CONCLUSION AND CLINICAL RELEVANCE

BoNT-A injection could lead to a disruption of protein levels and signaling pathways, a condition subsequently associated with muscle growth. This finding might aid clinicians in optimizing the management of spasticity in children with CP.

The Rehabilitation Interventions and Adaptive Technologies Used for Treating Patients With Cerebral Palsy

Cerebral palsy (CP) is one of the most common disorders in pediatric patients. The prevalence of CP is 2-3 in 1,000 live births, but various changes in some trends are seen in different groups. This article is a systematic review of multiple sources available for interventions and new adaptive techniques used for treating patients for their better lifestyles. With recent advancements, it is possible to diagnose a child who is below six months to two years. For achieving goals, proper interventions and techniques are necessary in the early stages of the disease. This article summarizes the rehabilitation and interventions available for treating these children with the best procedures.

Adverse events after different forms of botulinum neurotoxin A injections in children with cerebral palsy: An 8-year retrospective study

AIM

To compare the risks of adverse events 3 months after Onabotulinumtoxin-A and Lanbotulinumtoxin-A injections in children with cerebral palsy (CP) and to identify risk factors and associations.

METHOD

A total of 1037 children (682 males, 355 females; mean age 5 years 2 months [SD 3 years]; age range 2 years-17 years 10 months) with CP underwent 1013 Onabotulinumtoxin-A injections and 418 Lanbotulinumtoxin-A injections from 2012 to 2021. Information was recorded in a purpose-built database.

RESULTS

The adverse event rates of Onabotulinumtoxin-A and Lanbotulinumtoxin-A were reported as 13.92% and 11.96% respectively. Most adverse events were mild and self-limiting. Children in Gross Motor Function Classification System (GMFCS) levels IV to V had a higher risk of adverse events than those in GMFCS levels I to III (odds ratio [OR] [95% confidence interval {CI}] = 3.65 [1.56, 5.40], p < 0.01). The history of recent illness and higher dose increased the likelihood of adverse events (OR [95% CI] = 2.00 [1.55, 3.00] and 2.20 [1.53, 3.07] respectively, p < 0.01). Sex, age, and the number of injections had no significant effect on adverse event rates (p > 0.05). The incidence of upper respiratory tract infection and lower respiratory tract infection after injections was weakly correlated with the incidence before injections (r = 0.36 and r = 0.27 respectively, p < 0.01).

INTERPRETATION

Occurrence of adverse events was similar between Onabotulinumtoxin-A and Lanbotulinumtoxin-A in children with CP. Dose, GMFCS level, and health background were risk factors.

WHAT THIS PAPER ADDS

The prevalence of adverse events was similar between Onabotulinumtoxin-A and Lanbotulinumtoxin-A in children with cerebral palsy (CP). The prevalence of adverse events increased with the severity of CP and the injected dose. Sex, age, and number of injections had no significant effect on the prevalence of adverse events.

Biofeedback assisted relaxation training and distraction therapy for pain in children undergoing botulinum neurotoxin A injections: A crossover randomized controlled trial

AIM

To compare biofeedback assisted relaxation training (BART) with distraction therapy for pain during botulinum neurotoxin A (BoNT-A) treatment.

METHOD

This was a crossover randomized controlled trial. Eligible participants were 7 years and older with neurological conditions. Participants were randomized to receive BART or distraction during their first BoNT-A treatment, followed by the alternative intervention in their subsequent BoNT-A treatment. BART was delivered via BrightHearts, an interactive heart-rate-responsive application. Outcomes were pain (Faces Pain Scale - Revised), fear (Children's Fear Scale), and anxiety (numerical rating scale, State-Trait Anxiety Inventory). Demographics, paired t-tests, and linear mixed models were used to compare outcomes.

RESULTS

Thirty-eight participants (mean [SD] age 13 years 5 months [3 years 4 months], 20 males, 34 with cerebral palsy) completed both interventions. There were non-significant differences in overall pain (mean difference - 0.05, 95% confidence interval [CI] -0.91 to 0.80, p = 0.902) and worst pain (mean difference 0.37, 95% CI -0.39 to 1.13, p = 0.334) when using BART and distraction therapy. There were non-significant differences in fear and anxiety between interventions. Younger age, heightened pre-procedural state anxiety, and Gross Motor Function Classification System levels III and IV were associated with poorer outcomes (p < 0.05). Participants who received BART before distraction therapy reported lower pain and anxiety scores during both BoNT-A treatments (p < 0.05).

INTERPRETATION

Children reported similar pain when using BART and distraction therapy. Those who used BART before distraction therapy reported lower pain and anxiety during both treatments.

WHAT THIS PAPER ADDS

Children reported similar pain (overall; worst) when using biofeedback assisted relaxation training (BART) and distraction therapy. Children who used BART before distraction therapy reported lower pain and anxiety over both botulinum neurotoxin A treatments. Younger age, pre-procedural state anxiety, and Gross Motor Function Classification System levels III and IV predicted a worse pain experience. Distraction therapy and BART were acceptable non-pharmacological interventions for procedural pain management.

Upper Limb Onabotulinumtoxin A Injections in Children Under 2 Years with Cerebral Palsy: A Retrospective Chart Review

Aim: To report on the safety of using Onabotulinumtoxin A (OnaA) in the upper limb(s) of children <2 years of age with cerebral palsy and to describe a proactive clinical model of care in the management of upper limb impairment in children with cerebral palsy. Methods and procedures: Retrospective chart audit of 65 infants aged 13-23 months (mean 18.69) who received upper limb OnaA injections. Administration procedures, trends in muscle selection, and adverse events were examined. Results: Adverse events were reported in 6 (4%) of the 65 children. Across the study period, muscles that control thumb and forearm movements were most commonly injected. The number of OnaA injections to subscapularis and flexor digitorum profundus increased over this period. Conclusions and implications: OnaA is a safe treatment option for the short-term management of focal upper limb muscle overactivity in children under 2 years of age with cerebral palsy. In line with existing evidence, OnaA should always be considered as an adjunct to evidence-based therapy.

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.

Improved Sitting Balance in Children with Cerebral Palsy: Body Functions to Activity and Participation

The aim of this study is to evaluate the changes in activity and participation domains of International Classification of Functioning (ICF), Disability and Health, in children with cerebral palsy (CP) who received integrated botulinum toxin A (BoNT-A) treatment with intensive rehabilitation with a treatment goal of improved sitting balance. In this prospective observational study, 29 patients with CP (mean age: 6.7 ± 3.8 years) and the Gross Motor Function Classification System (GMFCS) levels of IV and V were included. The primary outcome measures were the mean changes from baseline to posttreatment weeks 10 to 12 of the Child and Adolescent Scale of Participation (CASP) and Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD). The modified Ashworth scale (MAS) and Tardieu scale (TS) results at 6 to 8 weeks of posttreatment were the secondary outcome measures. Statistically significant improvements in home and community participation of CASP (p < 0.001 and 0.001), CPCHILD (p < 0.01), MAS (p < 0.001), and all parameters of TS (p < 0.05) were recorded after treatment. The result of this prospective, observational study showed that the functional improvements in sitting balance by the integrated BoNT-A treatment provides positive effects on activity and participation levels of the patient and quality of life of patients and their families.

A consensus statement on the use of botulinum toxin in pediatric patients

Botulinum toxin has been used in medicine for the past 30 years. However, there continues to be controversy about the appropriate uses and dosing, especially in the pediatric population. A panel of nine pediatric physiatrists from different regions and previous training programs in the United States were nominated based on institutional reputation and botulinum toxin (BoNT) experience. Based on a review of the current literature, the goal was to provide the rationale for recommendations on the administration of BoNT in the pediatric population. The goal was not only to review safety, dosing, and injection techniques but also to develop a consensus on the appropriate uses in the pediatric population. In addition to upper and lower limb spasticity, the consensus also provides recommendations for congenital muscular torticollis, cervical dystonia, sialorrhea, and brachial plexus palsies.

Long-term effect of botulinum toxin A on the hip and spine in cerebral palsy: A national retrospective cohort study in Taiwan

Objectives

To investigate the effect of botulinum toxin A (BTA) on the development of hip dislocation and scoliosis, surgical rates for hip and spine, and mortality in cerebral palsy (CP).

Study design

A cohort study was conducted using CP data from a Taiwan National Insurance Health Research Database. Diagnoses were defined using the International Classification of Diseases codes, 9th revision. Adjusted hazard ratios for outcomes were calculated using Cox regression analysis and adjusted for the following variables: BTA injection, sex, age, severities of CP, comorbidities, location, urbanization level, and level of care.

Results

A total of 1,405 CP children (670 female vs. 735 male), 281 in the BTA group and 1,124 in the controls, were followed-up for a mean of 5 years 4 months. There were no significant differences in the outcomes in both groups, in the incidence rates of hip dislocation and scoliosis, nor in the surgical rates for hip and spine surgery. Mortality rate in the BTA group was 0.49 times lower than that in the controls (p = 0.001). Moderate to severe types of CP had higher incidence rates of hip dislocation, scoliosis, hip surgery, spine surgery, and mortality.

Conclusion

Moderate to severe types of CP had poorer outcomes in all aspects, including a higher risk of hip dislocation, scoliosis, surgical rate for hip and spine, and mortality. Although BTA injection in children with CP proved to not significantly reduce hip dislocation and scoliosis, it is considered safe as an anti-spasticity treatment and may be beneficial for survival.

Adverse events associated with paediatric intrathecal baclofen in Australia: 5 years of data collection

AIM

This study aims to examine the adverse event (AE) rate for intrathecal baclofen (ITB) therapy in an Australian paediatric population and to clarify type and frequency of AEs.

METHODS

AE data were extracted from the Australian Paediatric ITB Research Group national database, to include the first 5 years of data collection. Raw data were collated and analysed descriptively.

RESULTS

Data were collected for 40 patients. Forty-seven AEs in 23 patients were reported. Ten (25%) patients required surgical intervention related to their AE. Five patients (12.5%) required pump removal. The most frequent ITB-related AEs were catheter dysfunction (24%), drug overdose, withdrawal or sensitivity (19%), seromas and haematomas (15%) and infections (13%).

CONCLUSIONS

The AE rate for ITB therapy is high and needs to be considered when counselling patients regarding ITB as a therapeutic option.

[Multilevel botulinum toxin treatment in severe spastic forms of cerebral palsy (GMFCS IV-V)]

OBJECTIVE

To evaluate the most typical target muscles and dosages for the first and repeated botulinum toxin A (BTA) injections in cerebral palsy (CP) patients with severe motor deficit - GMFCS IV-V.

MATERIAL AND METHODS

A retrospective analysis of 677 protocols of the first and repeated Abobotulinumtoxin A (AboA) injections in 333 patients with CP GMFCS IV and V, aged 1 to 18 years, was carried out.

RESULTS

Ninety-seven percent of patients received multilevel injections. In the lower extremities the most typical target muscles were: m.gracilis - 221 (66.4%) patients, hip adductors - 164 (49.2%), medial hamstring - 144 (43.2%). In the upper extremities the most typical muscles were: m.pronator teres - 237 (71.2%) patients, m.biceps brachii+m.brachialis - 197 (59.2%). The total dosages of AboA and dosages for every target muscle were calculated. Several patients required high dosages (more than 30 U/kg of AboA). Higher dosages per kg were used in younger children and for repeated injections. The age-related evolution of spastic patterns was described. Adverse events were observed in 36 cases (5.3% of all injections).

CONCLUSION

The majority of patients with GMFCS IV-V required multilevel BTA injections in high dosages, especially in young age. Described selection of target muscles and dosages of AboA could be taken into account as a practical experience and reference for the BTA therapy in GMFCS IV-V patients.

Botulinum Toxin Type A injections for pediatric spasticity: Keeping our patients informed and practices safe

Serious adverse events (serious AEs) following the therapeutic use of Botulinum Toxin Type A (BoNT-A) are infrequent. Children with pediatric spasticity often have comorbidities that can cloud causation around an adverse event (AE). If a serious AE occurs, clear documentation of information sharing and informed consent as well as the provider-patient relationship are critical to minimizing litigation risks. Reviewing the litigation that has occurred following BoNT-A for pediatric spasticity can offer insight into how providers' perspectives regarding this intervention may differ from those of the public who might serve as jurists. This article offers suggestions for content sharing during the consent process to optimize patient understanding about potential adverse events.

Diaphragm neuromuscular transmission failure in a mouse model of an early-onset neuromotor disorder

The spa transgenic mouse displays spasticity and hypertonia that develops during the early postnatal period, with motor impairments that are remarkably similar to symptoms of human cerebral palsy. Previously, we observed that spa mice have fewer phrenic motor neurons innervating the diaphragm muscle (DIAm). We hypothesize that spa mice exhibit increased susceptibility to neuromuscular transmission failure (NMTF) due to an expanded innervation ratio. We retrogradely labeled phrenic motor neurons with rhodamine and imaged them in horizontal sections (70 µm) using confocal microscopy. Phrenic nerve-DIAm strip preparations from wild type and spa mice were stretched to optimal length, and force was evoked by phrenic nerve stimulation at 10, 40, or 75 Hz in 330-ms duration trains repeated each second (33% duty cycle) across a 120-s period. To assess NMTF, force evoked by phrenic nerve stimulation was compared to force evoked by direct DIAm stimulation superimposed every 15 s. Total DIAm fiber number was estimated in hematoxylin and eosin-stained strips. Compared to wild type, spa mice had over twofold greater NMTF during the first stimulus train that persisted throughout the 120 s period of repetitive activation. In both wild type and spa mice, NMTF was stimulation-frequency dependent. There was no difference in neuromuscular junction morphology or the total number of DIAm fibers between wild type and spa mice, however, there was an increase innervation ratio (39%) in spa mice. We conclude that early-onset developmental neuromotor disorders impair the efficacy of DIAm neuromuscular transmission, likely to contribute to respiratory complications.NEW & NOTEWORTHY Individuals with motor control deficits, including cerebral palsy (CP) often have respiratory impairments. Glycine-receptor mutant spa mice have early-onset hypertonia, and limb motor impairments, similar to individuals with CP. We hypothesized that in the diaphragm of spa mice, disruption of glycinergic inputs to MNs would result in increased phrenic-DIAm neuromuscular transmission failure. Pathophysiologic abnormalities in neuromuscular transmission may contribute to respiratory dysfunction in conditions where early developmental MN loss or motor control deficits are apparent.

Medical Updates in Management of Hypertonia

Identifying the subtypes of hypertonia is becoming increasingly important. Treatment strategies, including tone-modulating surgical interventions, medication type and dosing, and chemodenervation, may differ depending on the type of hypertonia present. It is important to delineate how hypertonia interferes with function and quality of life so that the appropriate intervention can be selected at the right time. Outcomes of treatment depend heavily on clear communication of goals. Botulinum toxin should not be used in isolation but as an adjunct to rehabilitation modalities.

A prospective study investigating gross motor function of children with cerebral palsy and GMFCS level II after long-term Botulinum toxin type A use

BACKGROUND

The aim of this study is to contribute to the knowledge base on the long-term outcomes of evidence-based medical interventions used to improve gross motor function in children and adolescents with Cerebral Palsy.

METHOD

Prospective cohort study of children with Cerebral Palsy in the birth years 2000-2009 attending a tertiary level service for children with Cerebral Palsy who's first recorded Gross Motor Function Classification System level was II.

RESULTS

A total of 40 children were eligible for the study, of whom 28 (72.7%) enrolled. The Botulinum toxin A treatment for this cohort, (median and interquartile ranges) were: total number of lower limb Botulinum toxin A injections 11 (6.7, 5.5); total dose of Botulinum Toxin A per lower limb treatment 6.95 u/kg (4.5, 11); and dose of Botulinum Toxin u/kg/muscle 2.95 (2.2, 4). For all 28 subjects there was a median of 15 (8.5 to 22) Gross Motor Function Classification System level recordings: six of the 28 children (21.4%) improved from level II to level I, the remaining 22 children remained stable at level II (78.6%). In this highly treated population, the average 66 item Gross Motor Function Measure score for the 22 children in level II was 72.55, which is consistent with the mean of 68.5 reported in the original Ontario cohort.

CONCLUSION

This cohort study has confirmed that children with Cerebral Palsy, Gross Motor Function level II treated at a young age with repeated doses of Botulinum Toxin A within an integrated comprehensive service, maintain or improve their functional motor level at a later age.

A risk-stratified approach toward safely resuming OnabotulinumtoxinA injections based on dosing and ambulatory status in pediatric patients with cerebral palsy during the Coronavirus pandemic of 2019 (COVID-19)

PURPOSE

After the onset of the Coronavirus pandemic of 2019-2020 (COVID-19), physicians who inject OnabotulinumtoxinA (BoNT-A) were left with determining risks and benefits in pediatric patients with cerebral palsy. Many of these patients have pre-existing conditions that make them more prone to COVID-19 symptoms, and this susceptibility potentially increases after BoNT-A injections.

METHODS

A retrospective chart review of 500 patients identified 256 pediatric patients with cerebral palsy who received an intramuscular BoNT-A injection to determine relative doses used for each Gross Motor Functional Classification Score (GMFCS). Data regarding age, weight, GMFCS, BoNT-A total body dosage, and inpatient hospitalizations for 6 months post-injection were collected. Differences between GMFCS levels were analyzed using one-way analysis of variance testing. Inpatient hospitalizations were recorded and assessed using relative risk to determine the population risk of hospitalization in the setting of initiating injections during the COVID-19 pandemic.

RESULTS

Based on GMFCS level, patients who were GMFCS I or II received fewer units of BoNT-A medication per kilogram of body weight compared to GMFCS III-V (p< 0.0005, F= 25.38). There was no statistically significant difference in frequency or time to hospitalization when comparing patients receiving BoNT-A compared to a control group.

CONCLUSIONS

Resumption of BoNT-A injections during the time of COVID-19 requires a systematic approach based on risks and potential benefits. Data from this analysis does not show increased risk for patients who received injections historically; however, recommendations for resumption of injections has not previously been proposed in the setting of a pandemic. In this manuscript, a tiered approach to considerations for injections was proposed. Botulinum toxin type A injections have a history of improving spasticity in the pediatric patient with cerebral palsy. Ensuring appropriate selection of patients for injection with BoNT-A during this pandemic is increasingly important.

A pragmatic approach to Botulinum Toxin safety

Botulinum Toxin (BoNT) is widely used to treat hypertonia in pediatric patients. Although serious adverse events (AEs) occur infrequently, they can lead to significant patient morbidity and mortality. This paper will discuss potential safety risks that may affect outcomes, medical comorbidities, medication dosing, targeting techniques, and muscle morphology. It is the responsibility of the physician to discuss risks and benefits regarding the use of BoNT and mitigate risks of AEs while maximizing the effectiveness of the medication.

Botulinum toxin and surgical intervention in children and adolescents with cerebral palsy: who, when and why do we treat?

INTRODUCTION

This audit aimed to increase understanding of the long-term outcomes of evidence-based medical and surgical interventions to improve gross motor function in children and adolescents with Cerebral Palsy.

METHODS

Retrospective audit of a birth cohort (2000-2009) attending a tertiary service in Western Australia.

RESULTS

The cohort comprises 771 patients aged 8 to 17 years. Percentage of children receiving no Botulinum Toxin treatments in each Gross Motor Functional Classification System level was: I: 40%, II: 26%, III: 33%, IV: 28% and V: 46%. Of the total cohort, 53% of children received 4 or less Botulinum Toxin treatments and 3.7% received more than 20 treatments. Statistically significant difference in the rate of use of Botulinum Toxin pre and post-surgery (p < 0.001) was documented. Children levels IV and V had 5 times the odds of surgery compared to children levels I-III (Odds Ratio 5.2, 95% Confidence Interval 3.5 to 7.8, p < 0.001). For 578 (75%) of participants the last recorded level was the same as the first.

CONCLUSION

This audit documents medical intervention by age and Gross Motor Functional Classification System level in a large cohort of children with cerebral palsy over time and confirms stability of the level in the majority.IMPLICATIONS FOR REHABILITATIONThe information from this audit may be of use in discussions with families regarding the timing and use of Botulinum toxin and surgical intervention for motor function in children and adolescents with Cerebral Palsy.Long term use of Botulinum Toxin within an integrated evidence-based clinical program is not associated with loss of gross motor function in the long term as evidenced by the maintenance of Gross Motor Functional Classification System stability.

Systemic adverse events after botulinum neurotoxin A injections in children with cerebral palsy

AIM

To identify factors that increase the likelihood of systemic adverse events after botulinum neurotoxin A (BoNT-A) injections in children with cerebral palsy (CP).

METHOD

A prospective observational study of patients attending a BoNT-A clinic at a tertiary paediatric hospital (2010-2014). Occurrences of systemic adverse events, defined as lower respiratory tract illnesses, generalized weakness, dysphagia, and death were determined at follow-up. The relationship between systemic adverse events and eight preinjection variables (age, Gross Motor Function Classification System [GMFCS] level, history of dysphagia, gastrostomy, aspiration pneumonia, recent history of illness, BoNT-A dose, and type of sedation) were examined using univariable and multivariable logistic regression with generalized estimating equations methods.

RESULTS

In total 591 children underwent 2219 injection episodes with follow-up in 2158 (97%) cases. Systemic adverse events were reported in 77 (3.6%) injection episodes. Univariable analysis suggested that GMFCS levels IV and V, a history of dysphagia, gastrostomy, aspiration pneumonia, and increasing BoNT-A dose increase the likelihood of systemic adverse events. In multivariable analysis, a history of dysphagia (odds ratio [OR] 3.42) and/or aspiration pneumonia (OR 2.31) remained associated with increased likelihood of systemic adverse events.

INTERPRETATION

A history of dysphagia and/or aspiration pneumonia are the factors that most increase the likelihood of systemic adverse events after BoNT-A.

WHAT THIS PAPER ADDS

Systemic adverse events occur in 3.6% of botulinum neurotoxin A (BoNT-A) injection episodes. Dysphagia and/or aspiration pneumonia are associated with increased likelihood of systemic adverse events. Multivariable models showed no evidence of association between Gross Motor Function Classification System and systemic adverse events. Multivariable models showed no evidence of association between BoNT-A dose and systemic adverse events.