The use of botulinum toxin type A in the treatment of Frey and crocodile tears syndromes

Post Herpetic Frey's Syndrome

Frey's syndrome is characterized by unilateral sweating and flushing of the skin in the area of the parotid gland, occurring during meal, or on salivary stimulation. It is a common complication following surgery/injury in the parotid gland region/temporomandibular joint surgery; however, very few cases have been reported of its occurrence following herpetic infection. It is important for the clinician to recognize its unusual symptoms as early as possible to prevent its potential negative social and psychological effect on the patient. It is diagnosed on clinical presentation and confirmed by objective testing methods. The treatment ranges from topical application of glycopyrrolate to local injections of botulinum toxin and lastly to surgical intervention. An interesting case of Frey's syndrome is presented in a young patient having the previous history of herpes zoster infection, which was diagnosed clinically and confirmed by starch-iodine test and was successfully treated with topical application of glycopyrrolate.

Efficacy and safety of botulinum toxin type A for treatment of Frey's syndrome: evidence from 22 published articles

Frey’s syndrome (FS) is an unavoidable sequela following the surgery of the parotid gland. Although several treatment methods are available, their efficacy is short term or accompanied by unacceptable complications. In the past two decades, botulinum toxin type A (BTXA) has been widely used to treat FS. Although several systematic reviews have been reported recently, they were conflicting and with obvious deficiencies. Thus, we performed an objectively systematic review to determine whether BTXA is an effective and safe treatment for FS. A literature retrieval covering PubMed, Web of Science, Ovid, Embase and Cochrane library was performed on 16 January, 2015. Proportion meta-analysis and corresponding 95% confidence interval (CI) were performed to evaluate the efficacy and safety of BXTA in treatment of FS. A total of 499 records were retrieved and 22 articles with 23 studies were included after scrutiny by two independent authors. Statistical analyses regarding the effective rate, incidence of complications were used to estimate the efficacy and safety of BTXA. Our results suggested that the effective rate of BTXA for treatment of FS is 98.5% (95% CI = 0.971–0.994) and the incidence of complication is 3.6% (95% CI = 0.017–0.061). In conclusion, our study supports that BTXA produces meaningful benefits on the treatment of patients with FS. However, owing to lack of strong evidence, future studies with well-designed inclusion criteria and multicenter randomized controlled trials are needed to give more credible evidence, if possible.

Disorders and tumors of the salivary glands in children

Salivary gland neoplasms are rare in children. In infants most tumors are benign hemangiomas, with some notable exceptions, such as sialoblastomas. An asymptomatic swelling in the periauricular region is the most common presenting complaint in older children. Approximately 50% of these lesions are malignant, which dictates a thorough diagnostic evaluation by a head and neck surgeon. Surgical excision is the primary treatment modality. Prognosis is primarily determined by histopathologic findings. This review discusses neoplastic lesions of the salivary glands in children, and malignant epithelial tumors in particular.

Botulinum toxin: The Midas touch

Botulinum Toxin (BT) is a natural molecule produced during growth and autolysis of bacterium called Clostridium botulinum. Use of BT for cosmetic purposes has gained popularity over past two decades, and recently, other therapeutic uses of BT has been extensively studied. BT is considered as a minimally invasive agent that can be used in the treatment of various orofacial disorders and improving the quality of life in such patients. The objective of this article is to review the nature, mechanism of action of BT, and its application in various head and neck diseases.

Intraglandular injection of botulinum toxin a reduces tear production in rabbits

PURPOSE

To develop an animal model and investigate the dose-dependent effect of an intraglandular injection of botulinum toxin A (BTX-A) on tear production.

METHODS

In a volume of 0.1-ml, 0.625-, 1.25-, or 2.5-U BTX-A was injected transconjunctivally in the superolateral lobe of the lacrimal gland of adult New Zealand white female rabbits. In the contralateral lacrimal gland, 0.1 ml of 0.9% sodium chloride was injected. Prior to injection and at 1-week postinjection, photographs were taken to evaluate pre- and postoperative eyelid position. Fluorescein and Rose Bengal stain were used to evaluate the corneal surface, and Schirmer test was used to assess tear production.

RESULTS

Glands injected with the intermediate (1.25 U) and the highest (2.5 U) doses of BTX-A displayed a statistically significant decrease in tear production (p = 0.002 and 0.007, respectively) compared with the contralateral saline-injected glands at 1 week. No corneal pathologic factors from excessive dryness were observed following the injection. While postinjection ptosis was observed (p = 0.025), no difference was seen between BTX-A and saline-injected eyes.

CONCLUSIONS

In rabbits, intraglandular injection of BTX-A resulted in decreased tear production at 1 week. No additional reduction in tear production was seen with a BTX-A dose greater than 1.25 U, suggesting glandular receptor saturation at this dose. Despite suppression of tear production, no corneal pathologic factors were observed. Further studies are needed to refine this animal model with the ultimate goal of determining optimum delivery route and concentration to reduction in tear production while minimizing side effects in patients.

Uses of Botulinum Toxin a in Ophthalmology

Introduction:

Botox® (serotype A) is currently available and used to treat various ophthalmological conditions. The aim of our study was to review the current indications, side-effects and updates on the clinical use of botulinum toxin- A (Btx-A) in the field of ophthalmology.

Methods:

A literature search using the keywords “Botulinum Toxin”, “Botulinum Toxin A”, “Botox” and “Ophthalmology” was performed using Pubmed. Articles describing the use of botulinum toxin A were selected and reviewed.

Results:

The uses of Btx-A in ophthalmology can be broadly classified into four categories: eyelid, strabismus, cosmetic and others. In the eyelid, it can be used to treat blepharospasm, hemifacial spasm, apraxia of lid opening or induce ptosis in lid retraction and exposure keratopathy. In strabismus management, it can be injected into overacting muscles to realign the eyes. For cosmesis, it can be used to relax facial muscles to reduce wrinkles while other indications include treatment of chronic dry eye, lacrimal hypersecretion and pain relief in acute angle closure attack. Complications of the injection include local effects like ecchymosis, pain or infection and spillover effects like ptosis, diplopia, lagophthalmos, mid facial weakness and dry eyes.

Conclusion:

The clinical application of botulinum toxin A in ophthalmology is extensive. When considering its application in clinical practice, one should be mindful of the indications, risks and benefits of the procedure. When properly delivered, its potential as an efficacious, minimally-invasive treatment modality can be maximised in patient management.

Management of Frey syndrome

Almost all patients who undergo parotidectomy will to some extent develop Frey syndrome (auriculotemporal syndrome or gustatory sweating) after surgery, because of aberrant regeneration of cut parasympathetic fibers between otic ganglion and subcutaneous vessels. However, only the minority of these patients needs treatment. The syndrome consists of gustatory sweating, flushing, and warming over the preauricular and temporal areas. Thick skin flap and partial superficial parotidectomy are the most important techniques to minimize the risk of developing symptomatic Frey syndrome. Intracutaneous injection of botulinum toxin A is an effective, long-lasting, and well-tolerated treatment of Frey syndrome. If recurrence occurs, the treatment can be repeated.

A comprehensive approach to the recognition, diagnosis, and severity-based treatment of focal hyperhidrosis: recommendations of the Canadian Hyperhidrosis Advisory Committee

BACKGROUND

Hyperhidrosis can have profound effects on a patient's quality of life. Current treatment guidelines ignore disease severity.

OBJECTIVE

The objective was to establish clinical guidelines for the recognition, diagnosis, and treatment of primary focal hyperhidrosis.

METHODS AND MATERIALS

A working group of eight nationally recognized experts was convened to develop the consensus statement using an evidence-based approach.

RECOMMENDATIONS

An algorithm was designed to consider both disease severity and location. The Hyperhidrosis Disease Severity Scale (HDSS) provides a qualitative measure that allows tailoring of treatment. Mild axillary, palmar, and plantar hyperhidrosis (HDSS score of 2) should initially be treated with topical aluminum chloride (AC). If the patient fails to respond to AC therapy, botulinum toxin A (BTX-A; axillae, palms, soles) and iontophoresis (palms, soles) should be the second-line therapy. In severe cases of axillary, palmar, and plantar hyperhidrosis (HDSS score of 3 or 4), both BTX-A and topical AC are first-line therapy. Iontophoresis is also first-line therapy for palmar and plantar hyperhidrosis. Craniofacial hyperhidrosis should be treated with oral medications, BTX-A, or topical AC as first-line therapy. Local surgery (axillary) and endoscopic thoracic sympathectomy (palms and soles) should only be considered after failure of all other treatment options.

CONCLUSIONS

These guidelines offer a rapid method to assess disease severity and to treat primary focal hyperhidrosis according to severity.

Botulinumtoxin bei Überfunktion der Tränendrüse, spastischem Entropium und Oberlidretraktion bei endokriner Orbitopathie

After proximal facial nerve lesions, misrouting of nerve fibres may cause the phenomenon of crocodile tears. Transconjunctival injections of botulinum toxin in the palpebral part of the lacrimal gland are the treatment of choice. An initial dose of 2.5 U of toxin is recommended, and injections may be repeated after 6 months if symptoms reoccur. Botulinum toxin A is also a highly effective temporary treatment for involutional (spasmodic) entropion until surgery is performed. A dose of 10 U of botulinum toxin is injected in the pretarsal part of the lower lid near the eyelashes. Botulinum toxin treatment is also effective for dysthyroid upper eye lid retraction, especially in instable thyroid disease or mild retraction. Slight transient ptosis may occur in some cases. Depending on the amount of retraction, a dose of 5 or 7.5 U of toxin is injected into the subconjunctival space at the superior margin of the tarsal plate.

Low-dose subcutaneous injection of botulinum toxin type A for facial synkinesis and hyperlacrimation

OBJECTIVE

To investigate the efficacy of low dose of botulinum toxin type A (BTX-A) for facial synkinesis and hyperlacrimation.

MATERIAL AND METHODS

Eleven patients suffering from facial synkinesis after Bell's palsy or facial nerve injury were treated with a low dose of BTX-A, 0.5-1.25 U per point into several points. One patient showing hyperlacrimation was also treated with BTX-A. The whole observational period was 43 months.

RESULTS

On average, 5.76 U of BTX-A, which was lower than that of previous reports, was injected per treatment. In seven cases, synkinesis disappeared completely after three or fewer sessions of BTX-A injection. The mean interval between treatments was 14.5 weeks. Hyperlacrimation was completely suppressed after a single subcutaneous injection of BTX-A. Only mild subcutaneous hemorrhage was observed as adverse reactions.

CONCLUSION

Facial synkinesis can be treated with a lower dose of BTX-A without relevant adverse reactions.

Use of botulinum toxins in cancer therapy

A recent study has demonstrated for the first time that botulinum neurotoxin (BoNT) briefly opens tumour vessels, allowing more effective destruction of cancer cells by radiotherapy and chemotherapy. This review discusses the implications of BoNTs in cancer treatment. After briefly reviewing the different BoNT serotypes, their pharmacological activities and their general use in medicine, the authors focus on their possible application in cancer and describe how BoNTs have been used so far to treat spasm related to tumour or to therapies. By dissecting the mechanisms of action leading to a potentiation of anticancer therapy, it can be seen that BoNTs act by an effect on the tumour microenvironment rather than by a direct cytotoxic effect on tumour cells.

Comparison of topical dry eye medications for the treatment of keratoconjunctivitis sicca in a botulinum toxin B-induced mouse model

PURPOSE

To compare the effects of topical dry eye medications including anti-inflammatory agents and lubricant eyedrops for the treatment of keratoconjunctivitis sicca (KCS) in a botulinum toxin B (BTX-B)-induced mouse model.

METHODS

CBA mice were randomized into 10 groups. The first 5 groups received a transconjunctival injection of saline into the lacrimal gland, and the remaining groups were injected with 0.05 mL of 20 mU BTX-B. Each group received treatment with 0.1% fluorometholone (FML), 0.05% cyclosporine A (CsA), a 50:50 combination of FML and CsA, artificial tears, or saline 3 days after injections. Tear production, corneal staining, and blink rate were compared in each of the 10 groups.

RESULTS

Tear production in BTX-B-injected CsA-treated, FML-treated, and combined-treated groups started to return to baseline level within 2 weeks of treatment, whereas those treated with saline or artificial tears still exhibited reduction of lacrimation up to 4 weeks after injection. Topical FML significantly reversed the staining score within 1 week of treatment. The improvement of corneal staining in BTX-B-challenged combined-treated and CsA-treated groups occurred later within 2 weeks after treatment. No significant improvement in corneal staining was observed for the BTX-B-injected mice treated with artificial tears or saline. No significant changes were noted in blink frequency between the control and study groups undergoing the various dry eye therapies.

CONCLUSION

The therapeutic effects of dry eye medications in a BTX-B-induced mouse model of KCS are similar to the human response.

Diagnosis, Impact, and Management of Focal Hyperhidrosis: Treatment Review Including Botulinum Toxin Therapy

Idiopathic localized hyperhidrosis, called for hyperhidrosis, affects almost 3% of the US population. The most frequent anatomic sites of involvement include the axillae, palms, soles, and face. For those affected, this condition can be extremely socially debilitating and interfere with work activities. Until recently, frequently ineffective topical regimens or problematic surgical procedures have been the treatments of choice. Since 1996, intracutaneous injections of botulinum toxin have been used as a minimally invasive treatment for this condition with numerous studies documenting safety, efficacy, and extremely high levels of patient satisfaction. Botulinum toxin type A (Botox) was approved by the US Food and Drug Administration in 2004 for the treatment of axillary hyperhidrosis.

Duration of botulinum toxin effect in the treatment of crocodile tears

PURPOSE

To provide clinical evidence of the duration of botulinum toxin type A (BTX-A) effect when applied in the palpebral lobe of the lacrimal gland in patients with gustatory epiphora.

METHODS

Prospective, nonrandomized, nonblinded study. Patients with history of gustatory epiphora were included. A Schirmer test was performed to quantify tearing induced by chewing. Clinical examination included visual acuity, tear-duct syringing, slit lamp examination, corneal staining, and eyelid malpositions. A questionnaire was completed by each patient to asses the severity of hyperlacrimation. A single dose of 2.5 units of BTX-A was injected directly into the lacrimal gland palpebral lobe. Patients were evaluated before and at 1, 4, 12, and 24 weeks after injection. The same person performed the examination and the BTX-A injection. Descriptive statistics, using repeated measures and a paired t test, were used for statistical analysis.

RESULTS

Fifteen patients were included. Mean age was 63 years. Before BTX-A injection, mean Schirmer test values were 5.47 mm in the unaffected eyes (NAE) and 12.07 mm in the affected eyes (AE). When comparing Schirmer test values in the AE before and after BTX-A injection, there were statistically significant differences (p < 0.05). Only 2 patients developed mild transitory ptosis. No other complications were noted.

CONCLUSIONS

The effect of 2.5 units of BTX-A injected into the lacrimal gland lasted 6 months, a duration similar to that reported for other application sites.

Botulinum Toxin in Ophthalmology

Since its introduction into clinical medicine in 1980, botulinum toxin has become a major therapeutic drug with applications valuable to many medical sub-specialties. Its use was spearheaded in ophthalmology where its potential applications have expanded to cover a broad range of visually related disorders. These include dystonic movement disorders, strabismus, nystagmus, headache syndromes such as migraine, lacrimal hypersecretion syndromes, eyelid retraction, spastic entropion, compressive optic neuropathy, and, more recently, periorbital aesthetic uses. Botulinum toxin is a potent neurotoxin that blocks the release of acetylcholine at the neuromuscular junction of cholinergic nerves. When used appropriately it will weaken the force of muscular contraction, or inhibit glandular secretion. Recovery occurs over 3 to 4 months from nerve terminal sprouting and regeneration of inactivated proteins necessary for degranualtion of acetylcholine vesicles. Complications are related to chemodenervation of adjacent muscle groups, injection technique, and immunological mechanisms.

Botulinum toxin: Clinical use

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.

The use of botulinum toxins to treat hyperhidrosis and gustatory sweating syndrome

Hyperhidrosis is a chronic condition characterized by excessive sweating. Recent studies report that it affects approximately 2.8% of the population and typically begins during adolescence. Gustatory sweating usually occurs after parotid gland injury or surgery, and both disorders can be debilitating for those who are affected. Both diseases respond very well to botulinum toxin therapy and this article will review the use of botulinum toxins, including the serotypes used, dosing, and complications.