Secondary Effects of Botulinum Toxin Injections Into Salivary Glands for the Management of Pediatric Drooling:

Onabotulinum Toxin A (BoNT-A) for Drooling in Children: A Systematic Review and Meta-Analysis

INTRODUCTION

Sialorrhea, also known as drooling, hypersalivation, or ptyalism, has a significant impact on the medical and psychosocial well-being of children. Onabotulinum toxin A (BoNT-A) is the most commonly used botulinum toxin worldwide for the treatment of sialorrhea in children.

OBJECTIVES

To conduct a comprehensive systematic review and meta-analysis to assess the clinical efficacy and potential adverse effects of BoNT-A as a treatment for drooling in children.

METHODS

Cochrane, Embase, and Medline databases were systematically searched (up to May 2023). Out of 535 identified publications, 20 were found eligible for inclusion. A systematic review and meta-analysis were performed to determine the efficacy of BoNT-A treatment in children in reducing the frequency and severity of drooling.

RESULTS

Out of the 20 studies included, a meta-analysis was conducted on the complete dataset of eight studies involving 131 patients. BoNT-A was found to significantly decrease the severity of drooling in patients with sialorrhea (standardized mean difference [SMD], -2.07; 95% confidence interval [CI], -2.91 to -1.23; p < 0.0001) when compared with the conditions before injections using random-effects models. Six studies out of 20 reported dysphagia as an adverse effect after injection. Other side effects included thickness of saliva and pain at the site of injection.

CONCLUSION

BoNT-A is a clinically effective therapy that improves drooling severity in children with sialorrhea. Although there were some adverse side effects reported, they were transient and not severe. Future studies are needed to further evaluate the best techniques and to identify the ideal dosages required to achieve the optimal outcomes. Laryngoscope, 134:3012-3017, 2024.

Comparing the evidence for botulinum neurotoxin injections in paediatric anterior drooling: a scoping review

Paediatric anterior drooling has a major impact on the daily lives of children and caregivers. Intraglandular botulinum neurotoxin type-A (BoNT-A) injections are considered an effective treatment to diminish drooling. However, there is no international consensus on which major salivary glands should be injected to obtain optimal treatment effect while minimizing the risk of side effects. This scoping review aimed to explore the evidence for submandibular BoNT-A injections and concurrent submandibular and parotid (i.e. four-gland) injections, respectively, and assess whether outcomes could be compared across studies to improve decision making regarding the optimal initial BoNT-A treatment approach for paediatric anterior drooling. PubMed, Embase, and Web of Science were searched to identify relevant studies (until October 1, 2023) on submandibular or four-gland BoNT-A injections for the treatment of anterior drooling in children with neurodevelopmental disabilities. Similarities and differences in treatment, patient, outcome, and follow-up characteristics were assessed. Twenty-eight papers were identified; 7 reporting on submandibular injections and 21 on four-gland injections. No major differences in treatment procedures or timing of follow-up were found. However, patient characteristics were poorly reported, there was great variety in outcome measurement, and the assessment of side effects was not clearly described.   Conclusion: This review highlights heterogeneity in outcome measures and patient population descriptors among studies on paediatric BoNT-A injections, limiting the ability to compare treatment effectiveness between submandibular and four-gland injections. These findings emphasize the need for more extensive and uniform reporting of patient characteristics and the implementation of a core outcome measurement set to allow for comparison of results between studies and facilitate the optimization of clinical practice guidelines. What is Known: • There is no international consensus on which salivary glands to initially inject with BoNT-A to treat paediatric drooling. What is New: • Concluding on the optimal initial BoNT-A treatment based on literature is currently infeasible. There is considerable heterogeneity in outcome measures used to quantify anterior drooling.and clinical characteristics of children treated with intraglandular BoNT-A are generally insufficiently reported. • Consensus-based sets of outcome measures and patient characteristics should be developed and implemented.

Botulinum Toxin A in the Management of Pediatric Sialorrhea: A Systematic Review

OBJECTIVE

Botulinum toxin A is known to be effective and safe in managing sialorrhea in pediatric patients; however, there is no consensus on a protocol for optimal injection sites and appropriate dosing for injection.

METHODS

This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol. PubMed, EMBASE, and other databases were queried to identify articles that evaluated botulinum toxin type A for the treatment of sialorrhea in the pediatric population. A total of 405 studies were identified. After applying inclusion and exclusion criteria, 31 articles were included for review.

RESULTS

A total of 14 studies evaluated 2-gland injections, and 17 studies evaluated 4-gland injections. Of the 31 studies included, one study assessed incobotulinumtoxinA (Xeomin®) the remaining all used onabotulinumtoxinA (Botox®). For 2-gland injection studies, a combined total of 899 participants were reviewed, where 602 participants received 50 units into their submandibular glands, while 262 participants received 30 to 50 units. Among 4-gland injection studies, there was a combined total of 388 participants, with the most prevalent dosage utilized being 60 to 100 units in 230 participants, followed by 100 units total in 77 participants. The most common adverse event was dysphagia which resolved in nearly all cases. Three studies aimed to examine 2-gland versus 4-gland injections, with 2 of the studies concluding 4-gland injection was superior.

CONCLUSIONS

The strength of evidence suggests that the dosing of 50 units total of onabotulinumtoxinA to the submandibular glands is safe and effective in the pediatric population. For 4-gland injections, bilateral submandibular and parotid gland injections of 60 to 100 units total is the safe and effective dosage. There is no substantial evidence comparing 4-gland injections to 2-gland injections, but research thus far suggests 4-gland injections to be superior. Future study is needed to evaluate incobotulinumtoxinA and abobotulinumtoxinA dosages in the pediatric population.

A multidisciplinary approach and consensus statement to establish standards of care for Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a rare neurogenetic disorder present in approximately 1/12,000 individuals and characterized by developmental delay, cognitive impairment, motor dysfunction, seizures, gastrointestinal concerns, and abnormal electroencephalographic background. AS is caused by absent expression of the paternally imprinted gene UBE3A in the central nervous system. Disparities in the management of AS are a major problem in preparing for precision therapies and occur even in patients with access to experts and recognized clinics. AS patients receive care based on collective provider experience due to limited evidence-based literature. We present a consensus statement and comprehensive literature review that proposes a standard of care practices for the management of AS at a critical time when therapeutics to alter the natural history of the disease are on the horizon.

METHODS

We compiled the key recognized clinical features of AS based on consensus from a team of specialists managing patients with AS. Working groups were established to address each focus area with committees comprised of providers who manage >5 individuals. Committees developed management guidelines for their area of expertise. These were compiled into a final document to provide a framework for standardizing management. Evidence from the medical literature was also comprehensively reviewed.

RESULTS

Areas covered by working groups in the consensus document include genetics, developmental medicine, psychology, general health concerns, neurology (including movement disorders), sleep, psychiatry, orthopedics, ophthalmology, communication, early intervention and therapies, and caregiver health. Working groups created frameworks, including flowcharts and tables, to help with quick access for providers. Data from the literature were incorporated to ensure providers had review of experiential versus evidence-based care guidelines.

CONCLUSION

Standards of care in the management of AS are keys to ensure optimal care at a critical time when new disease-modifying therapies are emerging. This document is a framework for providers of all familiarity levels.

Addition of Kinesio Taping of the orbicularis oris muscles to speech therapy rapidly improves drooling in children with neurological disorders

OBJECTIVE

To evaluate the effects of Kinesio Taping (KT) of the orbicularis oris muscles as an adjunct to standard therapy for drooling.

METHODS

Fifteen children with neurological disorders and drooling received speech therapy and twice-weekly KT of the orbicularis muscles over a 30-day period. Drooling was assessed by six parameters: impact on the life of the child and caregiver; severity of drooling; frequency of drooling; drooling volume (estimated by number of bibs used); salivary leak; and interlabial gap. Seven markers of oral motor skills were also assessed.

RESULTS

KT of the orbicularis oris region reduced the interlabial gap. All oral motor skills and almost all markers of drooling improved after 15 days of treatment.

CONCLUSION

In this sample of children with neurological disorders, adding KT of the orbicularis oris muscles to speech therapy caused rapid improvement in oral motor skills and drooling.

Negative effects of submandibular botulinum neurotoxin A injections on oral motor function in children with drooling due to central nervous system disorders

AIM

The aims of this study were: (1) to determine the incidence and nature of adverse effects on oral motor function after first injections of botulinum neurotoxin A (BoNT-A) in submandibular glands for excessive drooling in children with central nervous system disorders; and (2) to identify independent predictors of these adverse effects.

METHOD

A cohort study involved 209 children (123 males, 86 females, aged 4-27y, median 8y 4mo), who received submandibular BoNT-A injections for drooling. Adverse effects were categorized into swallowing, eating, drinking, articulation, and other problems. Univariable logistic regression was used to study differences in patients with and without adverse effects. Possible predictors were identified using multivariable logistic regression.

RESULTS

Transient adverse effects occurred in 33% of the 209 BoNT-A treatments. Almost 80% of these were mild, versus 8.7% severe. Approximately 54% of the adverse effects spontaneously resolved within 4 weeks; 3% still existed after 32 weeks. A diagnosis of cerebral palsy, higher range of BoNT-A dosage, and a pre-treatment drooling quotient <18% were found to be independent predictors of adverse effects.

INTERPRETATION

Before using submandibular BoNT-A injections for drooling, potential adverse effects should be discussed. Oral motor function needs to be monitored, because existing dysphagia may be worsened. The identified clinical predictors could be helpful to optimize patient selection.

Ultrasound-guided Botulinum Toxin-A Injections: A Method of Treating Sialorrhea

Neurological diseases can be complicated by sialorrhea, an excessive flow of saliva. Patients suffering from moderate to severe sialorrhea have an impaired quality of life, often worsened by correlated complications such as aspiration pneumonia, oral infections, dental caries, and maceration of the skin. Diverse therapeutic approaches have been proposed for the treatment of sialorrhea, including surgery and the use of anticholinergic agents, with limited results and the possible occurrence of serious adverse events. Recently, botulinum toxin (BoNT) injection within the major salivary glands has been proposed in patients refractory to anticholinergic therapy, with the aim of inhibiting local acetylcholine release and gland activity. In order to obtain a better outcome in terms of reduction of saliva production, efficacy, duration, and avoidance of major adverse events, we developed an ultrasound-guided BoNT-type A injection technique accurately described in the text. Here we present a method of treating sialorrhea with bilateral parotid and submandibular gland BoNT-type A injections under ultrasound guidance. Four quadrants of the parotid gland and two quadrants of the submandibular gland are visualized and injected using two accesses and one access, respectively. The ultrasound-guided procedure provides a simple, non-invasive, real-time visualization of the muscular and glandular tissues and their surrounding structures, optimizing treatment efficacy and safety.

Salivary botulinum toxin injection may reduce aspiration pneumonia in neurologically impaired children

OBJECTIVES

Neurologically impaired children often drool and aspirate saliva leading to recurrent aspiration pneumonia and frequent hospitalizations. Salivary botulinum toxin injection is known to reduce sialorrhea. This study evaluates whether this intervention affects the frequency and duration of respiratory infections including aspiration pneumonia and hospitalizations in neurologically impaired children.

METHODS

Retrospective review of patients treated with salivary botulinum toxin at a tertiary care pediatric hospital from January 2009 to December 2013. Each patient was their own control and 180 day pre-injection and post-injection time periods were compared. Outcomes evaluated included: number of hospital days, intensive care unit days, days of antibiotic treatment, chest X-rays, and infiltrates on chest X-ray.

RESULTS

13 patients accumulated 539 hospital days. All children were gastrostomy tube dependent. 54% were tracheostomy tube dependent. Amongst all patients, the total hospital days decreased from 385 to 154 (P=0.02), the mean days treated with antibiotics decreased from 214 to 47 (P=0.02), and the number of chest X-ray confirmed infiltrates decreased from 20 to 6 (P=0.02) after injection.

CONCLUSION

In this review, there was a decrease in hospitalized days, antibiotic usage, and chest X-ray infiltrates after the salivary botulinum toxin injection. A prospective study is needed to evaluate whether this treatment can prevent aspiration pneumonia in neurologically impaired children.

Botulinum Toxin A and B in sialorrhea: Long-term data and literature overview

INTRODUCTION AND OBJECTIVES

In recent years, Botulinum Toxin has been shown to be efficacious and safe in the treatment of sialorrhea, but scanty data are available on its long term use. The aim of this study was to investigate adverse events, discriminate differences in safety, and evaluate the efficacy of long-term use of both abobotulinumtoxinA and rimabotulinumtoxinB ultrasound-guided injections for sialorrhea in a retrospective trial. Moreover we review the literature on this topic.

PATIENTS AND METHODS

Consecutive patients with severe sialorrhea and receiving at least two ultrasound-guided intrasalivary glands abobotulinumtoxinA 250 U or rimabotulinumtoxinB 2500 U injections were included. Clinical and demographic data were collected. Safety and tolerability were assessed on the basis of patients' self-reports. Efficacy was assessed by recording the duration of benefit and by the Drooling Severity Scale and Drooling Frequency Scale 4 weeks after intervention. A review of literature was performed using 'Botulinum Toxin' and/or 'drooling' and/or 'sialorrhea' and/or 'hypersalivation' as keywords.

RESULTS

Sixty-five patients (32 Amyotrophic Lateral Sclerosis and 33 Parkinson's Disease) were treated in a total of 317 sessions (181 rimabotulinumtoxinB and 136 abobotulinumtoxinA). Both serotypes induced a clear-cut benefit in 89% of injections. Mean benefit duration was 87 days (range 30-240), similar for abobotulinumtoxinA and rimabotulinumtoxinB but significantly shorter in Amyotrophic Lateral Sclerosis group compared to Parkinson's Disease (p < 0.001). Older age was positively correlated to benefit duration (p = 0.003). Botulinum Toxin-related and injection-related side effects complicated respectively 8,2% and 1,5% of treatments. The only Botulinum Toxin-related adverse event was a change of saliva thickness, mostly rated mild to moderate and more frequent in Amyotrophic Lateral Sclerosis patients (p = NS).

CONCLUSIONS

Both 250 U abobotulinumtoxinA and 2500 U rimabotulinumtoxinB administered by ultrasound-guided intrasalivary gland injection are safe and effective in treating sialorrhea, even in long-term follow-up. Older age is significantly associated with longer benefit duration. Parkinson's Disease patients showed a more favorable safety-efficacy ratio than did Amyotrophic Lateral Sclerosis patients, due to lower adverse events (p = NS) and longer benefit duration (p < 0.001).

Botulinum toxin A for children with salivary control problems

OBJECTIVE

The aim of this study was to review the response of children who have received botulinum toxin A (BtA) injections for saliva control in our institution.

METHODS

Retrospective case series of children attending a saliva control clinic in a paediatric tertiary referral hospital. Children were identified from the saliva control database, which has been in place since its creation in 2006. Prior to receiving BtA all the children in the study had previously undertaken a 3-month trial of pharmacological therapy, with no effect. All BtA injections were performed freehand to the parotid and submandibular glands. The background diagnosis, comorbidities for the child, age at presentation, dose of BtA, the response, and any complications were recorded.

RESULTS

97 children were identified and 175 BtA doses were given (median per child: 1, mean: 1.9). 59 (61%) were male. The age range was between 2 months and 18 years (mean 8.6 years, median 8.8 years). The dose injected varied between 0.52 units/kg and 21.28 unit/kg (mean 5 units/kg, median 4.2 units/kg). These were performed using local anaesthetic on 131 (75%) occasions. The remainder were performed under general anaesthetic. Responses to BtA were classed as effective 109 (62%), partially effective 14 (8%) or not effective 50 (29%). The response duration was between 0.25 and 18 months (mean 4 months). Complications were seen following 22 injections (10.9%). Data modelled using binary logistic regression found that male gender and children with cerebral palsy are statistically predicted to have a better response to BtA.

CONCLUSION

Botulinum A injected under local anaesthetic is a safe, effective treatment for children with sialorrhoea. Ultrasound guidance is not necessary as long as anatomical landmarks are used for placement. The main adverse effect that can result is dysphagia, which is of concern in children that can swallow independently prior to injection. Male sex and cerebral palsy are statistically independent positive predictive factors for successful outcome of BtA injections for sialorrhoea, however this does not preclude other children from receiving or benefitting from it. Children that respond well to BtA initially, are likely to respond well in the future.