Treatment of relative sialorrhoea with botulinum toxin type A: description and rationale for an injection procedure with case report

From Toxin to Treatment: A Narrative Review on the Use of Botulinum Toxin for Autonomic Dysfunction

Since its regulatory approval over a half-century ago, botulinum toxin has evolved from one of the most potent neurotoxins known to becoming routinely adopted in clinical practice. Botulinum toxin, a highly potent neurotoxin produced by Clostridium botulinum, can cause botulism illness, characterized by widespread muscle weakness due to inhibition of acetylcholine transmission at neuromuscular junctions. The observation of botulinum toxin's anticholinergic properties led to the investigation of its potential benefits for conditions with an underlying etiology of cholinergic transmission, including autonomic nervous system dysfunction. These conditions range from disorders of the integument to gastrointestinal and urinary systems. Several formulations of botulinum toxin have been developed and tested over time, significantly increasing the availability of this treatment for appropriate clinical use. Despite the accelerated and expanded use of botulinum toxin, there lacks an updated comprehensive review on its therapeutic use, particularly to treat autonomic dysfunction. This narrative review provides an overview of the effect of botulinum toxin in the treatment of autonomic dysfunction and summarizes the different formulations and dosages most widely studied, while highlighting reported outcomes and the occurrence of any adverse events.

Botulinum Neurotoxin A in the Treatment of Pharyngocutaneous Fistula after Salvage Surgery in Head and Neck Cancer Patients: Our Preliminary Results

Objective: To analyze the effect of intraparotid injection of botulinum neurotoxin A (BoNT-A) on salivary production and the course of pharyngocutaneous fistula (PCF) in post-radiation therapy salvage surgery. Methods: A total of 13 patients who had undergone total laryngectomy or pharyngolaryngectomy were treated with BoNT-A to both parotid glands, within three days from PCF onset. The salivary flow was evaluated using a subjective rating scale as the percentage of normal function from 0% (no saliva) to 100% (normal saliva flow), before injection, every day for 2 weeks, and once a week for three months. PCFs were monitored daily. Results: Spontaneous closure of PCF occurred in 7/13 (53.84%) cases 13.6 days (range: 7-18) after treatment; 6/13 (46.16%) patients needed revision surgery. Salivary flow significantly decreased in all patients seven days after injection (from 67.2% to 36.4%; p < 0.05). Patients who had undergone either conservative or surgical treatment did not differ in salivary flow before injection, whereas the mean percentages of salivary flow calculated at each time point after injection were different (p < 0.05). Conclusions: BoNT-A contributed to the closure of the fistula in most of our cases. The subjective perception of salivary flow predicted the closure of PCF. The mean time to closure may contribute to establishing the timing of PCF surgical treatment.

Efficacy of Botulinum Toxin for Treating Sialorrhea in Neuromuscular Conditions

Background: Drooling related to bulbar weakness and dysfunction is a common concern in patients with neuromuscular disease. While there are numerous medications to manage sialorrhea, they are often limited by side effects and lack of efficacy. Botulinum toxin has shown to benefit ALS patients in a few studies, but there is scant data on the benefit in other neuromuscular conditions. Objective: To assess the effectiveness of Botulinum toxin in reducing sialorrhea in patients with various neuromuscular disease. Design/Methods: 25 patients (19M, 6F; 54.36 ± 17.09 yr) with documented neuromuscular illness and concern for drooling was followed for 6 weeks after Botulinum toxin injection. These patients had one of the following diagnoses: Duchenne muscular dystrophy (3), myotonic dystrophy (3), oculopharyngeal muscular dystrophy (1), inclusion body myositis (2), primary lateral sclerosis (1), amyotrophic lateral sclerosis (9), spinal muscular atrophy type 2 and 3 (2), spinal-bulbar muscular atrophy (2), and Becker's muscular dystrophy (2). A subjective drooling scale (1: markedly worse, 5: markedly better) and drooling thickness score (0=normal, 100=thick) was calculated on these patients prior to the injection and 4 and 6 weeks after the injection. Botulinum toxin 20-30 units were injected into bilateral parotid gland (70% of the dose) and submandibular gland (30% of the dose). Results: The drooling thickness score at before the injection was 75.2 ± 10.46. At 4 and 6 weeks, average scores reduced to 47.2 ± 6.14 and 18.8 ± 5.26, respectively (p < 0.05). The average pre injection perception about drooling was 3.0 (p < 0.05). The average change in perception was +0.84 and +1.28 at 4 and 6 weeks, respectively, (p < 0.05) implying significant improvement. There were no reported adverse effects. Conclusion: This study provides preliminary evidence for the use of botulinum toxin for refractory sialorrhea for a variety of neuromuscular conditions.

Sialorrhoea associated with sertraline use

INTRODUCTION

Sialorrhoea, which has been defined as excessive amount of saliva in the mouth, can be a debilitating symptom. Psychoactive drugs may cause an increase or decrease in saliva secretion. Antidepressant drugs, especially tricyclic antidepressants and less often serotonin reuptake inhibitors, are often associated with a decrease in salivation and the complaint of dry mouth.

CASE PRESENTATION

A 46-year-old male patient with complaints of being depressed, lack of motivation, irritability and difficulty in falling asleep was started on sertraline treatment and had trouble with sialorrhoea after the dose increase, without other causes of hypersalivation.

DISCUSSION

We could not find report of any case with antidepressant-associated sialorrhoea in the literature. Future cases may support a relationship between sertraline and sialorrhoea.

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.

An unusual complication of Botox treatment for sialorrhoea

INTRODUCTION

To illustrate the potential side effects and clinical efficacy of Botox injections in treating sialorrhoea.

PRESENTATION OF CASE

A 26-year-old patient with cerebral palsy with dystonia had a long history of severe, distressing sialorrhoea. She was treated with three separate Botox injections into her salivary glands in December 2011, July 2012 and March 2013.

DISCUSSION

Following the Botox injections the patient developed dysphagia, began to expectorate thick mucus and developed a cough; she was treated for a chest injection and during this time her feeding deteriorated. Three injections were given as the patient had an objective and significant reduction in salivation. However, the side effect profile was deemed too great to continue with treatment.

CONCLUSION

Botox is a novel and effective treatment for reducing saliva production. Its clinical efficacy is supported by this case and correlates with the recent literature. Although rare, significant side effects can happen and the case presented illustrates the care needed when administering injections, particularly in a subgroup of patients.

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.

Effect of botulinum toxin a injection into the salivary glands for sialorrhea in children with neurologic disorders

OBJECTIVE

To determine the 9 month period effect of botulinum toxin A (BoNT-A) injection into the salivary gland in children with neurologic disorders and sialorrhea by qualified parent/caregiver-administered questionnaires.

METHOD

A total of 17 patients (age 7.6±4.24 years) were enrolled in this study. The degree of sialorrhea was assessed at the baseline, 2 weeks, 1, 2, 4, 6 and 9 months after injection. The Drooling Count (DC) was assessed as an objective measurement. The Drooling Frequency and Severity Scale (DFS) and the Teacher Drooling Scale (TDS) were evaluated as a subjective measurement. BoNT-A (0.5 unit/kg) was injected into each submandibular and parotid gland under ultrasonography-guidance.

RESULTS

DC, DFS and TDS showed significant improvement at 2 weeks, 1, 2, 4, 6, and 9 months follow-up (p<0.05). Twelve of 17 cases (70.5%) showed more than 50% reduction in DC from the baseline value.

CONCLUSION

Ultrasonography-guided BoNT-A injection into the submandibular and parotid gland was a safe and effective method to treat sialorrhea in children with neurologic disorders.

Anatomical localization of submandibular gland for botulinum toxin injection

The aim of this study was to document the anatomical landmarks of the submandibular gland (SMG) for a botulinum toxin injection. Thirty-four SMGs from 20 cadavers were examined. The mean length of a reference line between the angle of the mandible and the gnathion was 94.8 ± 5.9 mm, the proximal and distal point of the SMG from the angle of the mandible was 10.6% (11.5 ± 3.5 mm) and 41.8% (40.9 ± 5.2 mm), respectively. The facial artery came out of the SMG at 11.6% (14.6 ± 3.4 mm) and the position of the intersection of the facial artery with the inferior border of the mandible was located at 24.4% (28.0 ± 5.5 mm) from the angle of the mandible. The shape of the SMG was generally triangular or irregular round on the anatomical position. The mean superior-inferior diameter, anterior-posterior diameter and medial-lateral diameter of the gland was 28.8 ± 4.1, 30.0 ± 6.1 and 15.1 ± 3.5 mm, respectively. The safety zone for the injection was 20-35% from the mandible angle on the inferior view and 1.5 cm below the inferior line of the mandible on the lateral view. In addition, the needle should be inserted to a depth of 2.0 cm from the skin surface on the inferior view. These results may assist in determining a accurate localization of injection sites for the SMG, particularly for injections without ultrasound guidance.

Botulinum toxin treatment of sialorrhea: comparing different therapeutic preparations

In recent years, a number of potential new therapeutic indications of botulinum toxin injections have emerged, amongst which sialorrhea has attracted considerable attention. Based on open-label and controlled studies, botulinum toxin can be used to improve sialorrhea in patients with Parkinson's disease, parkinsonian syndromes, motor neuron disease and cerebral palsy. The toxin can be injected blindly based on anatomic landmarks of the salivary glands, or localization can be facilitated by use of ultrasound guidance. There are few reported adverse effects. However, many more carefully designed, controlled studies are still required to address the specific questions related to selection of patients, the optimal injection technique, the appropriate dose of botulinum toxin and its long-term effects.

Expanding use of botulinum toxin

Botulinum toxin type A (BTX-A) is best known to neurologists as a treatment for neuromuscular conditions such as dystonias and spasticity and has recently been publicized for the management of facial wrinkles. The property that makes botulinum toxin type A useful for these various conditions is the inhibition of acetylcholine release at the neuromuscular junction. Although botulinum toxin types A and B (BTX-A and BTX-B) continue to find new uses in neuromuscular conditions involving the somatic nervous system, it has also been recognized that the effects of these medications are not confined to cholinergic neurons at the neuromuscular junction. Acceptors for BTX-A and BTX-B are also found on autonomic nerve terminals, where they inhibit acetylcholine release at glands and smooth muscle. This observation led to trials of botulinum neurotoxins in various conditions involving autonomic innervation. The article reviews the emerging use of botulinum neurotoxins in these and selected other conditions, including sialorrhea, primary focal hyperhidrosis, pathological pain and primary headache disorders that may be of interest to neurologists and related specialists.

[Treatment of sialorrhea with botulinum toxin: an overview]

Hypersalivation (sialorrhea) is a common complaint of patients with neurodegenerative disorders such as Parkinson's disease or amyotrophic lateral sclerosis and a frequently disabling side effect of atypical antipsychotic drugs. Conventional treatment including oral anticholinergic or antihistamine medication is often limited by adverse effects and lack of efficacy. Over the past few years, several studies reported decreased drooling after injections of botulinum toxin into the salivary glands. This review describes the current state of treatment of sialorrhea with botulinum toxin.

Botulinum toxin injections for children with excessive drooling

The objective of this study was to evaluate the feasibility of ultrasonography-guided injections of botulinum toxin A into the parotid glands of children with severe drooling (sialorrhea). Excessive drooling is common in children with chronic neurologic disorders. Preliminary observations in adults suggest that injections of botulinum toxin A into the parotid glands can decrease drooling, but the optimal dose, sites of injection, and concomitant use of imaging during injections and its use for children have not been established. Ultrasonography was used to guide the injection of botulinum toxin (10-25 IU) into both parotid glands of nine children with excessive drooling. Subjective and objective measures of the severity of drooling were collected before and after botulinum toxin A injections. A booster injection was provided if the initial response was inadequate. Injections were well tolerated, and no adverse reactions were observed. Ultrasonography revealed that the parotid gland showed a variable depth, extent, and vascularization. Eight of nine patients needed a booster injection after 1 month. Objective measures of drooling severity were improved in seven of nine patients. However, subjective improvement was reported in only three of nine patients, and this improvement was functionally significant in only one patient. Although intraparotid injection of botulinum toxin A is safe and causes a reduction in saliva production in children, the doses used in this study did not result in functionally significant improvement. Higher doses of botulinum toxin A in the parotid glands or concomitant injections into the submandibular glands can increase the efficacy of these injections. Variability in size, depth, and vascular supply of the parotid gland suggests the importance of ultrasonography guidance for optimizing injections. These results underscore the need for further studies to establish the efficacy of this treatment in children.

The management of oromandibular motor disorders and facial spasms with injections of botulinum toxin

Although much work is yet to be done in this area, nine general conclusions can be derived: 1. Local site-of-injection side effects from botulinum toxin injections are rare, assuming proper technique is used. 2. The two most common medication-related side effects from botulinum toxin orofacial injections are alterations in salivary consistency and inadvertent weakness of the swallowing, speech, and facial muscles. These complications are injection site-specific (eg, more common with lateral pterygoid injections and palatal and tongue muscle injections) and dose-dependent problems. These problems are bothersome but are not contraindications for the therapy if it is needed. 3. The data presented in this article are mostly case series-based and open trial-based information that is promising, but randomized, blinded, controlled trials are needed to establish the true efficacy of this method for the orofacial motor and pain disorders. 4. The novice should begin with injection of muscles he or she can inject with low risk of incorrect placement. The hard-to-find muscles should be avoided when starting out. The novice clinician should inject and dissect a few cadavers to improve injection technique. 5. The general latency for botulinum toxin type A is 1 week, its duration is 2 to 3 months, and it is recommended that injection be done no more than once every 12 weeks to avoid development of antibodies against the toxin. 6. Depending on the target muscle, injection dose is 10 to 50 U of Botox type A per site with a total dose of 200 U in the masticatory system. More than this can be used (400 U maximum) if other sites in the head and neck are included in the injection protocol. 7. Regarding injecting painful muscles that do not exhibit palpable muscle hardness or EMG-determined spasticity or observable involuntary movements but have chronic myofascial trigger points or the patient localizes them as the site of their chronic daily headache pain, botulinum toxin injections might be helpful used in this manner, but conclusive data for this controversial application of botulinum toxin are still missing. 8. Hemifacial spasm has the largest number of open-label, clinical trials, some of which have a 10-year follow-up. The conclusions reached by all of these reports is that treatment of hemifacial spasm with repeated injections of botulinum toxin has been highly successful and that the dose and relative effect of the injections are stable over time. 9. Although EMG-guided injection may be useful, EMG is neither practical nor needed in most situations for orofacial injections because most of the orofacial muscles are easily palpable muscles or have definitive bony landmarks to help with the localization process.

Management of Frey's syndrome and hypersialorrhea with botulinum toxin

Botulinum toxin (BTX) is a safe and reliable drug for the treatment of Frey's syndrome and hypersialorrhea. Currently, the intradermal injection of BTX is the standard treatment of Frey's syndrome. A disappearance of Frey's syndrome for 1 to 1.5 year could almost be promised. Recently, BTX was introduced for the treatment of hypersialorrhea. Although some questions exist about the optimal dosage and the type of major salivary glands that should be treated, hypersialorrhea was reduced in almost all affected children and adults for up to 6 months by using ultrasound-guided intraglandular BTX injections.

[Sialorrhea, hyperhidrosis and botulinum toxin]

OBJECTIVE

The first clinical studies indicate that Botox provides effective treatment for hyperhidrosis and sialorrhea. The aim of this work is to sum up current evaluation of this use.

METHOD

A systematic literature search was conducted on the Pub Med database, along with on chapters in other publications. The most interesting articles in relation to our own personal experience were chosen.

RESULTS

Despite recent use of BT to treat focal hyperhidrosis, there have been numerous publications since 1997. However, the injected areas have not been listed so frequently. Axillary hyperhidrosis has been studied most; it is also in this case and in the case of gustatory sweating that the best results have been obtained. Publications about palmar and especially plantar hyperhidrosis are much rarer, almost anecdotic. It has been demonstrated to a lesser extent that BT injections are effective in these cases. Literature about sialorrhea is just beginning. However, the reduction of the production of saliva following intra parenchymatic injection of toxin into the parotid and submandibular glands, thus rarifying drooling, has been demonstrated. For each of the pathological indications, both the injection techniques and the optimal doses remain to be determined.

DISCUSSION

Because BT blocks all cholinergic transmission, including the autonomous nervous system, it was plausible to expect a reduction in sweating and salivation on local injection of the product. In fact, the first publications indicated such efficiency without serious side effects. For hyperhidrosis, there has developed a consensus for making intracutaneous injections only. Of the injections in axillary areas, the palms of the hands, the plantar regions, the face or other cutaneous areas, palmoplantar hyperhidrosis is the least accessible, in any case causes the most technical problems, because of difficulty in pain management. For sialorrhea and the drooling that accompanies certain chronical neurological diseases, BT seems to have very promising effects. However, it has not been precisely determined whether to inject the parotid gland, the submandibular gland, or both. Necessary and sufficient means of targeting are still imprecise. It also remains to be determined the number of sites per gland and the doses to be injected.