Successful treatment of drooling in children with neurological disorders with botulinum toxin A or B

Understanding Clinical Effectiveness and Safety Implications of Botulinum Toxin in Children: A Narrative Review of the Literature

Since its first approval by the Food and Drug Administration in 1989 for strabismus, botulinum toxin indications of use have been widely expanded. Due to its anticholinergic properties, this toxin is currently approved in adult patients for the treatment of a wide range of neuromuscular, otolaryngologic, orthopedic, gastrointestinal, and urologic disorders. Approved pediatric indications of use include the treatment of blepharospasm associated with dystonia, strabismus, lower-limb spasticity, focal spasticity in patients with cerebral palsy, and neurogenic detrusor overactivity. Alongside these approved indications, botulinum toxin is extensively used off-label. Although several clinical studies have shown that botulinum toxin is effective and well-tolerated in children, uncertainties persist regarding its long-term effects on growth and appropriate dosing in this population. As such, further research is needed to better define the botulinum toxin risk-benefit profile and expand approved uses in pediatrics. This narrative review aimed to provide a broad overview of the evidence concerning the clinical effectiveness and safety of BoNT with respect to its principal authorized and non-authorized pediatric therapeutic indications, as well as to describe perspectives on its future use in children.

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.

Use of botox for sialorrhea and dysphagia in the neonatal population

INTRODUCTION

Botox is frequently used for sialorrhea in patients with compromised airways and those with etiologies causing difficulty with secretion management (i.e. strokes, neurologic disorders, etc.). There are no published studies regarding the use of botulinum toxin (BoNT) in the neonate population. We aim to discuss our experience and safety of BoNT use in the neonate population in regards to alleviating secretion management and airway protection.

METHODS

Retrospective review of neonates admitted to the neonatal intensive care unit (NICU) ≤12 months of age who received BoNT injection to submandibular (SMG) and parotid (PG) glands for sialorrhea/dysphagia. BoNT was administered under ultrasound (u/s) guidance by interventional radiology.

RESULTS

6 children were examined. 2 (33 %) were male. Avg NICU stay was 87.5 ± 33.1 days. 2 underwent surgical airway intervention prior to injection. Mean age at initial BoNT was 1.5 ± 0.7 months. Avg weight at injection was 4 ± 1.1 kg. Each PG and SMG were injected in 5/6 cases. Bilateral SMG were unidentified on u/s in 1 case and thus not injected. Dose range injected per gland was 5-15u. 100 % required tube feeds, 50 % with tubes distal to stomach (NJT/NDT). 83 % were completely NPO prior to injection and there was no noted clinical improvement in oral skills post injection. All had noted desats/apneas prior to injection and 83 % had reported decreased events post injection. 50 % had reported decrease O2 requirements and frequent suctioning 2wks after injection, however 2 (33 %) required surgical airway intervention after injection (trach, SGP/MDO). 4/6 (67 %) trialed medical therapy, anticholinergics being the most common. 50 % underwent 2nd injection (age = 6.5 ± 0.3 months) avg. 4.7 ± 0.7mo after 1st injection, and the same 3pts underwent 3rd injection (age = 12.5 ± 2.4 months) avg. 6.1 ± 2.5mo after 2nd injection. 1 pt. had a total 6 injections. There were no injection related complications.

CONCLUSION

BoNT injection is a safe, non-invasive alterative for management of sialorrhea in neonates. Further extensive study needs to be performed to identify the optimal dose per gland in this population.

Comparing botulinum toxin and 4-duct ligation for Sialorrhea in children - A systematic review

INTRODUCTION

Sialorrhea or drooling can result in physical and psychosocial complications, such as aspiration and social isolation. Treatment options include botulinum toxin into the salivary glands and 4-duct ligation (i.e., simultaneous ligation of the bilateral parotid and submandibular ducts). This systematic review aimed to compare the efficacy and complication rates of botulinum toxin and 4-duct ligation for the treatment of drooling in children.

METHODS

Following PRISMA guidelines, PubMed, Embase, Web of Science, and Cochrane Library were searched from inception through June 17, 2021 for studies examining the efficacy of botulinum toxin or 4-duct ligation for drooling in children. Data were summarized by pooled counts, percentages, and means. Complication rates were compared by a chi-squared test.

RESULTS

A total of 22 studies (n = 606) examining botulinum toxin and 5 studies (n = 124) examining 4-duct ligation were included. From 12 botulinum toxin studies (n = 211), mean drooling frequency and severity scores was 7.5 at baseline. Mean difference from baseline was -2.6 (n = 92) at 4 weeks follow-up, -2.1 at 8 weeks (n = 41), -2.1 at 12 weeks (n = 56), and - 2.1 at 16 weeks (n = 58). From 4 4-duct ligation studies (n = 103), mean baseline drooling frequency and severity score was 8.4. Mean difference was -3.7 at mean follow-up of 35.6 months (n = 103). Eighteen botulinum studies (n = 343) recorded 53 (15.5 %) complications, including thickened saliva (n = 9), dysphagia (n = 4), and cheek abscesses (n = 4). Four 4-duct ligation studies (n = 108) recorded 25 (23.1 %) complications, including parotid gland swelling (n = 4), aspiration pneumonia (n = 3), and oxygen desaturation (n = 3). There was no statistically significant difference in complication rates between botulinum toxin and four-duct ligation (p = 0.065).

CONCLUSION

Botulinum toxin injection and 4-duct ligation are both effective in improving sialorrhea in children and have comparable complication rates.

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 for Drooling in Adults with Diseases of the Central Nervous System: A Meta-Analysis

(1) Background: The purpose of this study was to determine whether the drooling of adult patients with diverse central nervous system diseases can be treated with botulinum toxin type A. (2) Methods: The Cochrane Library, MEDLINE, and Embase were all searched for studies that fit the inclusion criteria. The patients in the studies had to be adults (>18 years old), and the studies had to be randomized placebo-controlled trials, controlled trials, or prospective studies. Each study had to have enough quantifiable data available for meta-analysis. The primary outcome measure was the Drooling Severity and Frequency Scale (DSFS). (3) Results: The meta-analysis comprised three studies. A statistically significant difference in DSFS score between the treatment and control groups was observed in the meta-analysis, with an overall standardized mean difference of -0.9377 (95% CI, -1.2919 to -0.5836; p < 0.0001). A total of seven studies were ineligible for inclusion in the meta-analysis and were only assessed as qualitative data. All qualitative studies showed a significant reduction in DSFS score a few weeks or months after the injection of botulinum toxin. (4) Conclusions: Botulinum toxin type A is safe and effective as a treatment for drooling in adult patients with central nervous system diseases.

Botulinum Toxin Injections for Treatment of Drooling in Children with Cerebral Palsy: A Systematic Review and Meta-Analysis

Background: We aimed to review and analyse the effectiveness and safety of botulinum toxin type A (BoNT-A) injections for drooling in children with cerebral palsy. Data sources: We searched the EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) databases from inception to January 2020. Methods: We included randomized controlled trials and observational studies which (1) involved children with cerebral palsy, (2) used BoNT-A for control of drooling, and (3) provided quantitative evaluations of drooling before and after intervention with BoNT-A. Results: Twenty-one trials met the inclusion criteria. Most studies showed that BoNT-A injections are safe and efficacious as a treatment for drooling in children with cerebral palsy. Four trials had sufficient data to pool the results for the meta-analysis. Both the drooling quotient (p = 0.002) and drooling Ffrequency and severity scale (p = 0.004) supported this conclusion. Conclusion: BoNT-A injections are a safe, reversible, effective treatment for drooling control in children with cerebral palsy that can offer effectiveness for more than 3 months with few side effects. The dosage of BoNT-A should not exceed 4 units/kg. Further studies are required to determine the optimal dosage and target glands.

Placebo-Controlled Clinical Trial of IncobotulinumtoxinA for Sialorrhea in Children: SIPEXI

BACKGROUND AND OBJECTIVES

To investigate the efficacy and safety of repeated injections of incobotulinumtoxinA (incoBoNT/A) for treatment of chronic sialorrhea (drooling) associated with neurologic disorders (e.g., cerebral palsy, traumatic brain injury) or intellectual disability in children and adolescents in a prospective phase III study (SIPEXI [Sialorrhea Pediatric Xeomin Investigation]).

METHODS

The study enrolled 2- to 17-year-old patients with sialorrhea due to neurologic disorders or intellectual disability. Patients received body weight-dependent doses of incoBoNT/A (20-75 U). A main period with 1 injection cycle (placebo-controlled, double-blind, 6- to 17-year-olds) was followed by an open-label extension with up to 3 further cycles. An additional cohort of 2- to 5-year-olds received active treatment throughout the study. Coprimary endpoints were the change in unstimulated salivary flow rate (uSFR) from baseline to week 4 and the carers' Global Impression of Change Scale (GICS) rating at week 4. Adverse events were recorded.

RESULTS

In the main period, 220 patients aged 6-17 years were randomized and treated (148 patients in incoBoNT/A group, 72 patients in placebo group). A total of 35 patients aged 2-5 years received incoBoNT/A (no placebo). A total of 214 patients aged 6-17 years and 33 patients aged 2-5 years continued treatment in the open-label extension period. For the 6- to 17-year-olds, a significant difference between incoBoNT/A and placebo was seen in mean uSFR decrease (difference -0.06 g/min; p = 0.0012) and the carers' GICS rating (difference 0.28 points; p = 0.032) at week 4, in favor of active treatment. The secondary endpoints consistently supported these results. A sustained benefit was observed during the extension. Incidences of adverse events were comparable between incoBoNT/A and placebo and did not increase notably with repeated injections. The most common adverse events were respiratory infections. Efficacy and safety were also favorable in the uncontrolled cohort of 2- to 5-year-olds.

DISCUSSION

Both co-primary efficacy endpoints were reached and superiority of incoBoNT/A over placebo was confirmed. IncoBoNT/A (up to 75 U, up to 4 cycles) is an effective and well-tolerated treatment for sialorrhea associated with neurologic disorders in children.

TRIAL REGISTRATION INFORMATION

Clinicaltrials.gov: NCT02270736 (clinicaltrials.gov/ct2/show/results/NCT02270736); EU Clinical Trials Register: 2013-004532-30 (clinicaltrialsregister.eu/ctr-search/search?query=2013-004532-30).

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that injection of incobotulinumtoxinA decreases drooling in children aged 6 to 17 years with neurologic disorders.

A critical review of incobotulinumtoxinA in the treatment of chronic sialorrhea in pediatric patients

INTRODUCTION

Sialorrhea, also known as hypersalivation, ptyalis, or drooling, results in physical and psychosocial complications that may have a significant negative impact on quality of life for both the patient and their caregiver. The goal of pharmacological treatment is to reduce excessive salivary flow, while maintaining a moist and healthy oral cavity; until recently, however, few of the agents used to treat chronic sialorrhea have been approved in pediatric patients.

AREAS COVERED

This article summarizes early evidence for the use of botulinum neurotoxin A formulations in the treatment of children/adolescents with chronic sialorrhea, and findings of the recently completed phase III trial of incobotulinumtoxinA in this indication. Alternative therapies are also briefly discussed.

EXPERT OPINION

IncobotulinumtoxinA is the first botulinum neurotoxin A to be approved for the treatment of chronic sialorrhea in children and adults, following the results of phase III trials that demonstrate the efficacy and safety of the drug in these patients. The authors expect that the positive findings will result in updates to clinical guidelines for the treatment of children with chronic sialorrhea.

ABBREVIATIONS

AE, adverse event; AESI, adverse event of special interest; BoNT/A, botulinum neurotoxin A; CI, confidence interval; CP, cerebral palsy; DIS, drooling impact scale; DQ, drooling quotient; DSFS, Drooling Severity and Frequency Scale; GICS, Global Impression of Change Scale; LS, least squares; mTDS, modified Teacher's drooling scale; NR, not reported; PD, Parkinson's disease; SAE, serious adverse event; SE, standard error; SIAXI, Sialorrhea in Adults Xeomin Investigation; SIPEXI, Sialorrhea Pediatric Xeomin Investigation; SNAP-25, synaptosomal associated protein-25; TBI, traumatic brain injury; TDS, Teacher Drooling Scale; USA, United States of America; uSFR, unstimulated Salivary Flow Rate; VAS, visual analog scale.

Repeated onabotulinum neurotoxin A injections for drooling in children with neurodisability

AIM

To evaluate the effect of repeated onabotulinum neurotoxin A injections for the treatment of drooling in children with neurodisabilities.

METHOD

This was a retrospective cohort study, in which the first, second, and third onabotulinum neurotoxin A injection were compared within children treated between 2000 and 2020. Primary outcomes included drooling quotient, visual analogue scale (VAS), and treatment success defined as ≥50% reduction in drooling quotient and/or VAS 8 weeks after treatment. Each outcome was obtained at baseline and 8 weeks posttreatment.

RESULTS

Seventy-seven children were included (mean age at first injection: 8y 3mo, SD 3y 7mo, range 3-17y; 44 males, 33 females; 51.9% with cerebral palsy, 45.5% wheelchair-bound). The objective (drooling quotient) and subjective (VAS) effect after the second injection was lower compared to the first injection. The third injection showed less objective and significantly less subjective effect compared to the first injection. An overall success rate of 74.0%, 41.6%, and 45.8% were found for the first, second, and third injection respectively.

INTERPRETATION

Although onabotulinum neurotoxin A remained effective throughout the entire treatment course, there is less effect of subsequent onabotulinum neurotoxin A injections compared to the first. Although there might be a loss of effect after repeated injections, there is continued improvement for most children. What this paper adds Repeated injections show a diminished treatment effect after the second injection. A continued improvement is seen in most patients.

Exploring treatments for drooling in children with neurological disorders

Introduction: Drooling represents a major problem in the every-day life of pediatric patients with neurological disorders. The significant burden, both physical and socio-psychological, of the disorder requires adequate clinical evaluation and proper management. However, treating drooling remains a challenge for clinicians. This is a review of the most up-to-date therapeutic options for the treatment of drooling in the pediatric population, hence both conservative, pharmacological, and surgical approaches are discussed. Areas covered: Randomized clinical trials (RCTs), structured reviews, and case reports are included. Special focus is paid on the methods used to evaluate the efficacy and safety outcomes in the selected RCTs, trying to promote the use of more validated scales to assess drooling in the future. Expert opinion: The lack of reliable metrics to assess efficacy and safety outcomes in drooling limits researchers from identifying the best patient-suitable treatment. The relatively small number of clinical trials carried out over the last two decades is also due to the difficulty in assessing drooling using subjective scales. A key enabler for new efficient therapies stands in the introduction of accurate and robust metrics to measure treatment effectiveness on drooling.

The Effectiveness of Botulinum Toxin Type A Injections in the Management of Sialorrhea

OBJECTIVE

The aim of this study was to evaluate the effect of Botulinum toxin type A by injecting in the submandibular and parotid glands on the frequency and severity of sialorrhea.

METHODS

Pediatric patients who were referred to our department with sialorrhea were evaluated using their parents' frequency and severity scores of sialorrhea with visual analog scales before and after 3 months of botulinum toxin type A injections. Bilateral submandibular and parotid glands were injected with Botulinum toxin type A.

RESULTS

Twenty-seven pediatric patients who were referred to our department with a complaint of sialorrhea were included in this study. Seventeen patients were female and 10 were male. Severe sialorrhea with cerebral palsy was present in all the patients. There were no complications after the procedure.

CONCLUSION

Botulinum toxin A injected in the major salivary glands in pediatric patients with neurological disorders is a safe and effective method.

BoNT/AB hybrid maintains similar duration of paresis as BoNT/A wild-type in murine running wheel assay

The highly potent Botulinum neurotoxins (BoNT) are successful drugs to treat neuromuscular disorders. Efforts are being made to further reduce the injected BoNT dose and to lengthen the interval between treatments. Detailed knowledge of the BoNT structure-activity relationship (SAR) allows combining the best features of the different BoNT serotypes. Of all seven BoNT serotypes A-G, BoNT/A displays the highest potency despite low neuronal binding affinity, while BoNT/B exhibits much higher affinity. Recently, a new BoNT/AB hybrid (AABB) was constructed comprising the catalytic and translocation domain of BoNT/A and the 50kDa cell binding domain of BoNT/B. Here, we compared BoNT/A wild-type (AAAA) and AABB with regard to ex vivo potency and in vivo potency, efficacy and duration of action using the mouse phrenic nerve hemidiaphragm assay and the murine running wheel assay, respectively. The ex vivo potency of AABB was found to be 8.4-fold higher than that of AAAA. For the latter, two and 5 pg each of AAAA and AABB, respectively, were bilaterally injected into the calf muscles and mouse running wheel performance was automatically monitored during the following weeks to determine potency, efficacy and duration. Mice displayed a dose-dependent impairment of running performance. AABB showed potency, efficacy and duration equal to AAAA demonstrating successful exchange of the cell binding domain. AABB might combine the higher potency and longer duration of BoNT/A with the target specificity for the autonomic nervous system of BoNT/B. AABB might therefore constitute an improved treatment option for acetylcholine-mediated autonomic disorders such as hypersalivation or hyperhidrosis.

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).

Onabotulinumtoxin A Treatment of Drooling in Children with Cerebral Palsy: A Prospective, Longitudinal Open-Label Study

The aim of this prospective open-label study was to treat disabling drooling in children with cerebral palsy (CP) with onabotulinumtoxin A (A/Ona, Botox^®) into submandibular and parotid glands and find the lowest effective dosage and least invasive method. A/Ona was injected in 14 children, Mean age 9 years, SD 3 years, under ultrasonic guidance in six successive Series, with at least six months between injections. Doses and gland involvement increased from Series A to F (units (U) per submandibular/parotid gland: A, 10/0; B, 15/0; C, 20/0; D, 20/20; E, 30/20; and F, 30/30). The effect was assessed 2, 4, 8, 12, and 20 weeks after A/Ona (drooling problems (VAS), impact (0–7), treatment effect (0–5), unstimulated whole saliva (UWS) flow and composition)) and analyzed by two-way ANOVA. The effect was unchanged–moderate in A to moderate–marked in F. Changes in all parameters were significant in E and F, but with swallowing problems ≤5 weeks in 3 of 28 treatments. F had largest VAS and UWS reduction (64% and 49%). We recommend: Start with dose D A/Ona (both submandibular and parotid glands and a total of 80 U) and increase to E and eventually F (total 120 U) without sufficient response.

Repeated treatments of drooling with botulinum toxin B in neurology

OBJECTIVES

To investigate efficacy, saliva flow, and composition in repeated BoNT-B treatments of drooling.

MATERIALS AND METHODS

Seventeen neurological patients (median 66 years), referred for treatment of drooling participated in this observational study. Median total doses of 4000 units botulinum toxin type B (BoNT-B, Neurobloc(®)) were injected with at least 3 months intervals into parotid and submandibular glands using ultrasound guidance. Measures of drooling and saliva collection for analysis were obtained before treatment, and 6, 12, and eventually 18 weeks after.

RESULTS

Number of treatment series in each patient was 1-7. Compared to baseline, saliva flow rate and drooling were reduced 30-70% 6 weeks after treatment in the first series, while sodium, chloride, and total protein increased 20-80% (t-tests; P < 0.05). After 12 weeks, drooling was still significantly reduced, saliva flow tended to be, and saliva composition was back to baseline. Frequent side effects were viscous saliva and dry mouth. Due to fading effect in eight patients, individual decisions were taken to change from BoNT-B to BoNT-A. Similarly, the outcome was significantly reduced over time in six patients completing five subsequent BoNT-B treatment series (ANOVA; P < 0.05).

CONCLUSION

In the first series, BoNT-B treatment resulted in marked reduction of drooling and saliva flow rate with some relapse after 12 weeks. The viscous saliva was ascribed to increased total protein content and compensatory mechanisms related to ß-adrenergic receptor-specific actions. With patients needing long-term treatment, it should be noted that the efficacy of repeated BoNT-B may fade with time.

Relevance of intraglandular injections of Botulinum toxin for the treatment of sialorrhea in children with cerebral palsy: a review

BACKGROUND

After the age of 4 years, drooling becomes pathological and impacts the quality of life of children with cerebral palsy. Intraglandular injection of Botulinum toxin is one of the treatments available to limit this phenomenon.

AIMS

The objectives of this review were to validate the efficacy of Botulinum toxin injections for drooling in children with cerebral palsy, determine recommendations and identify potential side effects.

METHODS

We conducted a literature review from 2001 in the following databases: Embase, Pubmed and Cochrane using the keywords: sialorrhea, drooling, hypersalivation, Botulinum toxin, cerebral palsy and children. Only the articles evaluating the efficacy of Botulinum toxin in children with cerebral palsy over the age of 4 were researched.

RESULTS

Eight studies were found: 2 case studies, 3 open and non-controlled studies and 3 randomized controlled trials. Efficacy results in this indication are quite encouraging and the use of BTX injections is safe but the overall level of evidence of these studies was quite low.

CONCLUSION

However, intraglandular injection of Botulinum toxin has a place among the therapeutic array available for the management of sialorrhea in this population even if no standardized protocol is available yet.

Major surgical procedures in children with cerebral palsy

There are 3 surgical procedures that patients with cerebral palsy (CP) undergo that may be considered major procedures: femoral osteotomies combined with pelvic osteotomies, spine fusion, and intrathecal baclofen pump implant for the treatment of spasticity. Many complications are known to occur at a higher rate in this population, and some may be avoided with prior awareness of the preoperative pathophysiology of the patient with CP.

Sialorrhea: anatomy, pathophysiology and treatment with emphasis on the role of botulinum toxins

Sialorrhea or excessive drooling is a major issue in children with cerebral palsy and adults with neurodegenerative disorders. In this review, we describe the clinical features, anatomy and physiology of sialorrhea, as well as a review of the world literature on medical treatment using Yale University’s search engine; including but not limited to Medline and Erasmus. Level of drug efficacy is defined according to the guidelines of American Academy of Neurology. Current medical management is unsatisfactory. Topical agents (scopolamine and tropicamide) and oral agents (glyccopyrolate) combined render a level B evidence (probably effective); however, this treatment is associated with troublesome side effects. Double-blind and placebo-controlled studies of botulinum toxin (BoNT) provide a level A evidence for type B (two class I studies; effective and established) and both overall and individual B level of evidence for OnabotulinumtoxinA (A/Ona) and AbobotulinumtoxinA (A/Abo); these are probably effective. For IncobotulinumtoxinA (A/Inco), the level of evidence is U (insufficient) due to lack of blinded studies. Side effects are uncommon; transient and comparable between the two types of toxin. A clinical note at the end of this review comments on fine clinical points. Administration of BoNTs into salivary glands is currently the most effective way of treating sialorrhea.

Evidence-based review and assessment of botulinum neurotoxin for the treatment of secretory disorders

Botulinum neurotoxin (BoNT) can be injected to achieve therapeutic benefit across a large range of clinical conditions. To assess the efficacy and safety of BoNT injections for the treatment of certain hypersecretory disorders, including hyperhidrosis, sialorrhea, and chronic rhinorrhea, an expert panel reviewed evidence from the published literature. Data sources included English-language studies identified via MEDLINE, EMBASE, CINAHL, Current Contents, and the Cochrane Central Register of Controlled Trials. Evidence tables generated in the 2008 Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology (AAN) review of the use of BoNT for autonomic disorders were also reviewed and updated. The panel evaluated evidence at several levels, supporting BoNT as a class, the serotypes BoNT-A and BoNT-B, as well as the four individual commercially available formulations: abobotulinumtoxinA (A/Abo), onabotulinumtoxinA (A/Ona), incobotulinumtoxinA (A/Inco), and rimabotulinumtoxinB (B/Rima). The panel ultimately made recommendations for each therapeutic indication, based upon the strength of clinical evidence and following the AAN classification scale. For the treatment of axillary hyperhidrosis in a total of 923 patients, the evidence supported a Level A recommendation for BoNT-A, with a Level B recommendation for A/Abo and A/Ona and a Level U recommendation (insufficient data) for A/Inco and B/Rima. Five trials in 82 patients supported the use of BoNT in palmar hyperhidrosis, with a Level B recommendation for BoNT-A and a Level C recommendation for BoNT-B; individual formulations received a Level U rating due to insufficient data. BoNT (and all individual formulations) received a Level U recommendation for the treatment of gustatory sweating. Support for use of BoNT in sialorrhea was derived from eight trials in a total of 222 adults and children. Evidence supported a Level B recommendation for A/Abo, A/Ona, and B/Rima and a Level U recommendation for A/Inco. Evidence supported a Level B recommendation for A/Ona for the treatment of allergic rhinitis, based on two Class II studies in 73 patients. A lack of published studies for A/Abo, A/Inco, or B/Rima supported a Level U recommendation for those formulations. Further clarity on the optimal mode of administration and additional studies using other BoNT formulations are needed to fill current evidence gaps.

Salivary gland botulinum toxin injections for drooling in children with cerebral palsy and neurodevelopmental disability: a systematic review

AIM

The aim of this paper was to systematically review the efficacy and safety of botulinum toxin (BoNT) injections to the salivary glands to treat drooling in children with cerebral palsy and neurodevelopmental disability.

METHOD

A systematic search of The Cochrane Central Register of Controlled Trials, PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), EMBASE, and the Physiotherapy Evidence Database (PEDro) was conducted (up to 1 October 2011). Data sources included published randomized controlled trials (RCTs) and prospective studies.

RESULTS

Sixteen studies met inclusion criteria. Three outcome measures support the effectiveness of BoNT for drooling. One RCT found an almost 30% reduction in the impact of drooling on patients' lives, as measured by the Drooling Impact Scale (mean difference -27.45; 95% confidence interval [CI] -35.28 to -19.62). There were sufficient data to pool results on one outcome measure, the Drooling Frequency and Severity Scale, which supports this result (mean difference -2.71; 95% CI -4.82 to -0.60; p<0.001). There was a significant reduction in the observed number of bibs required per day. The incidence of adverse events ranged from 2 to 41%, but was inconsistently reported. One trial was terminated early because of adverse events.

INTERPRETATION

BoNT is an effective, temporary treatment for sialorrhoea in children with cerebral palsy. Benefits need to be weighed against the potential for serious adverse events. More studies are needed to address the safety of BoNT and to compare BoNT with other treatment options for drooling.

Dysphagia and aspiration in children

Aspiration is a significant cause of respiratory morbidity and sometimes mortality in children. It occurs when airway protective reflexes fail, especially, when dysphagia is also present. Clinical symptoms and physical findings of aspiration can be nonspecific. Advances in technology can lead to early diagnosis of dysphagia and aspiration, and, new therapeutic advances can significantly improve outcome and prognosis. This report first reviews the anatomy and physiology involved in the normal process of swallowing. Next, the protective reflexes that help to prevent aspiration are discussed followed by the pathophysiologic events that occur after an aspiration event. Various disease processes that can result in dysphagia and aspiration in children are discussed. Finally, the various methods for diagnosis and treatment of dysphagia in children are reviewed.

What could predict effectiveness of Botulinum Toxin to treat drooling: a search for evidence of discriminatory factors on the level of body functions or structures

BACKGROUND

The treatment of drooling is important to families that experience the daily impact and research to elucidate clinical factors that play a role in the outcome of drooling treatment should be encouraged.

AIM

To define clinical factors that influence therapy outcome of submandibular Botulinum Toxin (BoNT-A) injections for drooling.

METHODS

Prospectively collected data of 128 children with cerebral palsy were evaluated; 80 spastic and 48 dyskinetic movement disorder, mostly Gross Motor Function Classification System III and higher; over 70% had an IQ <70. In addition, 23 fully ambulant children with exclusively intellectual disability were treated for drooling by ultrasound-guided injections of BoNT-A into the submandibular glands. Salivary flow rates and drooling quotients were measured at baseline and at 8 weeks after injection. Extensive information about the oral motor performance was gathered. Successful clinical response was defined as a 50% reduction of the baseline Drooling Quotient; 85 children were responsive to BoNT-A and 66 children unresponsive.

RESULTS

Five nominated clinical factors that possibly could influence saliva reduction (head position, lip seal, voluntary control over the tongue, control of voluntary movement functions, and mental age) did not influence the responsiveness to BoNT-A.

INTERPRETATION

Other variables need to be considered to predict the outcome of BoNT-A treatment. This article describes the first attempt to reveal the contribution of body functions and structures to the outcome of BoNT-A submandibular injections.

Does motor performance matter in botulinum toxin efficacy for drooling?

The aim of this study was to define factors that influence therapy outcome of submandibular botulinum toxin injections for drooling in children with cerebral palsy or mental disability. We postulated that differences in response may be explained by the variation of dysfunctions in the various cerebral palsy subtypes. Prospectively collected data were evaluated of 80 spastic and 48 dyskinetic children, of whom 70% had an IQ of <70. In addition, the data of 23 fully ambulant children with mental disability only were examined. Flow and Drooling Quotient were assessed at baseline and at 8 weeks after injection. After treatment, both the Drooling Quotient and submandibular flow decreased in all children. Morbidity associated with the procedure was limited. Ninety-three children responded to botulinum. Decrease of submandibular flow in these children was associated with reduction of parotid flow. In those who did not respond to therapy, spread across all 3 diagnostic classifications, parotid flow increased after injection. Response failure is characterized by increased parotid flow after injection; however, the precise role of parotid flow in therapy failure remains unclear. We cannot predict who will respond to botulinum toxin to treat drooling.

Botulinum toxin type A on oral health in treating sialorrhea in children with cerebral palsy: a randomized, double-blind, placebo-controlled study

Intrasalivary gland injection of botulinum toxin type A is known to treat sialorrhea effectively in children with cerebral palsy. However, oral health may be compromised with escalating dose. In this randomized, double-blind, and placebo-controlled pilot trial, the authors aim to determine the therapeutic effect of low-dose, ultrasonography-controlled botulinum toxin type A injection to bilateral parotid and submandibular glands on oral health in the management of sialorrhea. Twenty children diagnosed with cerebral palsy were randomly assigned to 2 groups. The treatment group received botulinum toxin type A injections, whereas the control received normal saline in the same locations. The authors evaluated subjective drooling scales, salivary flow rate, and oral health (salivary compositions and cariogenic bacterial counts). A significant decrease was found in salivary flow rate at the 1- and 3-month follow-up in the botulinum toxin-treated group. The authors suggest that current protocol can effectively manage sialorrhea while maintaining oral health.

Botulinum toxin type B for sialorrhoea in children with cerebral palsy: a randomized trial comparing three doses

AIM

The aim of the present study was to evaluate the efficacy and safety of three doses of botulinum toxin type B (BoNT-B) in reducing persistent sialorrhoea in children with cerebral palsy (CP).

METHOD

Children with CP and refractory sialorrhoea were randomized to one of four groups: a control group and three experimental groups receiving a low (1500 mouse units [MU]), medium (3000 MU), or high (5000 MU) dose of BoNT-B respectively, into bilateral salivary glands. Drooling was measured using the Thomas-Stonell rating scale, and the weight and the number of bibs used per day were counted in all children at baseline, 4, and 12 weeks after BoNT-B injection.

RESULTS

Twenty-seven children (15 males, 12 females; mean age 7 y 10 mo, SD 1 y 6 mo; range 5-15 y) were randomized into a control (seven children: four males, three females) and experimental groups receiving low (six children: four males, two females), medium (seven children: four males, three females), and high (seven children: three males, four females) doses of BoNT-B respectively. All children had mixed neurological disorders consisting of spastic paraparesis, tetraparesis, dystonic movements, and ataxia. Gross Motor Function Classification System levels ranged from III to V, and all children had moderate or severe intellectual disability. Estimated means with their standard errors (SEM) of drooling were at baseline, 4, and 12 weeks respectively, as follows: control group, 12.1 (2.1), 11.9 (2.1), 11.8 (2.2), p for trend 0.992; low dose group, 13.8 (2.3), 11.4 (2.3), 13.9 (2.3), p for trend 0.952; medium dose group, 13.9 (2.1), 6.7 (2.1), 7.1 (2.1) p for trend 0.008; and for the high dose group 14.4 (2.1), 5.0 (2.1), 5.6 (2.1), p for trend 0.002. Side effects included dense saliva, xerostomia, and difficulty in swallowing, and were more frequent in the high-dose group.

INTERPRETATION

A 3000 MU injection of BoNT-B into the salivary glands significantly improved the frequency and severity of sialorrhoea in children with CP. The lower dose was ineffective, and the higher dose produced no greater benefit and more side effects.

Salivary parameters in Brazilian individuals with cerebral palsy who drool

BACKGROUND

Although drooling of saliva is considered abnormal in a child over 4 years of age, it has been estimated to occur in approximately in 10-37% of children with cerebral palsy.

AIM

The aim of this study was to evaluate the flow rate, pH and buffering capacity in saliva of Brazilian individuals with cerebral palsy who drool.

METHODS

Cross-sectional assessment of saliva from 139 individuals with cerebral palsy (3-16 years old) enrolled in a specialized rehabilitation centre in Sao Paulo, Brazil, divided into two groups, according to the presence (G1) or absence (G2) of drooling and controls (G3): G1 consisted of 63 individuals who drool; G2 consisted of 76 who do not drool; and G3 consisted of 47 individuals with no neurological damage of similar age and sex. Unstimulated whole saliva was collected and salivary flow rate (mL/min), initial pH and buffering capacity, by titration of saliva with a constant amount of 0.01 N HCl, were evaluated. The results from G1, G2 and G3 were compared by one-way anova and the χ(2) -test.

RESULTS

A higher percentage of severe drooling (60.3%) was observed compared with moderate (27.0%) and mild (12.7%) in the cerebral palsy individuals who drool and the prevalence of drooling was highest among children and adolescents with spastic quadriplegia. Significant reductions in salivary flow rate, initial pH, buffering capacity of whole saliva in pH range 6.0-6.9 and total buffering capacity occurred in G1 and G2 compared with G3.

CONCLUSION

All individuals with cerebral palsy present lower flow rate, pH and buffering capacity of saliva, which increases the risk of oral diseases.

Botulinum toxin assessment, intervention and aftercare for paediatric and adult drooling: international consensus statement

Many individuals with neurological problems or anatomical abnormalities of the jaw, lips or oral cavity may drool, which can impact on health and quality of life. A thorough evaluation of the patient's history, examination of the oral region by a speech pathologist and, in individuals over 3 years, a dental examination is warranted. Questionnaires with established validity such as the Drooling Impact Scale are useful assessment tools. A hierarchical approach to treatment is taken from least invasive therapies, such as speech pathology, to more invasive, such as injection of botulinum neurotoxin type-A (BoNT-A) into the salivary glands (parotid and submandibular). The wishes of the individual and their carer are crucial considerations in determining the suitability of the intervention for the patient. In the presence of dysphagia and cerebral palsy (CP), careful assessment is required prior to the injection of BoNT-A. Favourable responses to intervention include a reduction in the secretion of saliva and in drooling, as well as psychosocial improvements. BoNT-A is usually well tolerated, although potential side effects should be discussed with the patient and carer.

An update on the neurologic applications of botulinum toxins

Initially used to treat strabismus in the 1970s, botulinum toxin now has more than a hundred possible medical applications. Its utility in neurologic conditions has largely involved treating movement disorders (particularly dystonia and conditions with muscle hyperactivity), although practically any hyperkinetic movement disorder may be relieved by botulinum toxin, including hemifacial spasm, tremor, tics, myoclonus, and spasticity. Although initially thought to inhibit acetylcholine release only at the neuromuscular junction, botulinum toxins are now recognized to inhibit acetylcholine release at autonomic cholinergic nerve terminals, as well as peripheral release of neurotransmitters involved in pain regulation. Thus, their use in neurology has been expanded to include headache and other pain syndromes, as well as hypersecretory disorders. This article highlights some of the common neurologic conditions currently improved by botulinum toxins and reviews the scientific evidence from research studies and clinical experience with these conditions.

Thickened saliva after effective management of drooling with botulinum toxin A

AIM

The aim of this study was to evaluate the rheological properties of saliva after submandibular botulinum toxin type A (BoNT-A) injections.

METHOD

We enrolled 15 children (11 males and six females; age range 3-17 y, mean age 9 y 10 mo) diagnosed with spastic (n=9) or dyskinetic (n=6) quadriplegic cerebral palsy (CP); Gross Motor Function Classification System level IV or V; and two children with intellectual disability (IQ<70) who experienced moderate to severe drooling. Salivary flow rate and drooling quotient were measured at baseline and at different times after BoNT-A injections up to 24 weeks. The mucin concentration of saliva was analysed before and after BoNT-A treatment.

RESULTS

Both submandibular salivary flow rate (baseline 0.38 mL/min; 24 wks after injection 0.26 mL/min) and drooling quotient (baseline 42.5%; 24 wks 28.80%) were substantially reduced, with a concomitant increase in mucin concentration within 8 weeks after BoNT-A injection (from 0.612 to 1.830 U/mL). The parents of nine children observed thickened saliva. Swallowing and chewing were problematic in seven children. Two of these children needed treatment with mucolytics because of pooling of thickened saliva in the throat.

INTERPRETATION

When making decisions about the use of BoNT-A, the risk of problems with masticatory and swallowing functions as a result of thickening of saliva after BoNT-A treatment should be taken into account.