Botulinum toxin for refractory vocal tics

Tourette Syndrome Treatment Updates: a Review and Discussion of the Current and Upcoming Literature

PURPOSE OF REVIEW

This study aims to examine the treatments currently available for Tourette syndrome (TS) and to discuss evolving therapies, spanning behavioral, pharmacologic, complementary and alternative medicine, and neuromodulation approaches.

RECENT FINDINGS

Behavioral therapies have undergone several modifications to improve accessibility, including transitioning to a virtual format which is particularly important in the current pandemic. There are several recent or ongoing pharmacologic studies that have shown promise including the selective D1 receptor antagonist ecopipam and various cannabinoid compounds. Adaptive DBS may enable the physiologic markers of tics to determine stimulation parameters and improve tic outcomes related to neuromodulation. In recent years, there has been a wealth of research across multiple treatment domains in the TS field. This review highlights exciting and new potential options for the future treatment of patients with TS.

Medical and Surgical Treatments of Tourette Syndrome

Tourette syndrome is a complex neuropsychiatric disorder with a wide phenotypic spectrum, including tics and psychiatric comorbidities, such as obsessive-compulsive disorder and attention-deficit disorder. Often considered a neurodevelopmental disorder, it is most prevalent during childhood and treatment strategies can vary according to degree of severity and patient-specific symptom manifestations. This review focuses on established and emerging management options for tics, including behavioral interventions and nonpharmacologic therapies, medication management, and promising surgical approaches.

Clinical Aspects of Premonitory Urges in Patients with Tourette's Disorder

Most patients with Tourette’s disorder experience an uncomfortable sensory phenomenon called the premonitory urge immediately before experiencing tics. It has been suggested that premonitory urges are associated with comorbidities such as obsessive compulsive disorder, anxiety disorders, and attention-deficit/hyperactivity disorder, although these associations have been inconsistent. Most patients experience tics as a result of the premonitory urges, and after the tics occur, most patients report that the premonitory urges are temporarily relieved. As a consequence, several studies have assessed the premonitory urge and its potential therapeutic utility. Based on the concept that the premonitory urge induces tics, behavioral treatments such as Exposure and Response Prevention and Habit Reversal Therapy have been developed. However, it is still unclear whether habituation, the main mechanism of these therapies, is directly related to their effectiveness. Moreover, the observed effects of pharmacological treatments on premonitory urges have been inconsistent.

Botulinum Toxin Treatment of Movement Disorders

Botulinum neurotoxins (BoNTs) are now among the most widely used therapeutic agents in clinical medicine with indications applied to the fields of movement disorders, pain disorders, and autonomic dysfunction. In this literature review, the efficacy and utility of BoNTs in the field of movement disorders are assessed using the criteria of the Guideline Development Subcommittee of the American Academy of Neurology. The literature supports a level A efficacy (established) for BoNT therapy in cervical dystonia and a level B efficacy (probably effective) for blepharospasm, hemifacial spasm, laryngeal dystonia (spasmodic dysphonia), task-specific dystonias, essential tremor, and Parkinson rest tremor. It is the view of movement disorder experts, however, that despite the level B efficacy, BoNTs should be considered treatment of first choice for blepharospasm, hemifacial spasm, laryngeal, and task-specific dystonias. The emerging data on motor and vocal tics of Tourette syndrome and oromandibular dystonias are encouraging but the current level of efficacy is U (undetermined) due to lack of published high-quality studies.

Botulinum toxin for motor and phonic tics in Tourette's syndrome

BACKGROUND

Gilles de la Tourette syndrome, or Tourette's syndrome, is defined as the presence of both motor and vocal (phonic) tics for more than 12 months, that manifest before the age of 18 years, in the absence of secondary causes. Treatment of motor and phonic tics is difficult and challenging.

OBJECTIVES

To determine the safety and effectiveness of botulinum toxin in treating motor and phonic tics in people with Tourette's syndrome, and to analyse the effect of botulinum toxin on premonitory urge and sensory tics.

SEARCH METHODS

We searched the Cochrane Movement Disorders Group Trials Register, CENTRAL, MEDLINE, and two trials registers to 25 October 2017. We reviewed reference lists of relevant articles for additional trials.

SELECTION CRITERIA

We considered all randomised, controlled, double-blind studies comparing botulinum toxin to placebo or other medications for the treatment of motor and phonic tics in Tourette's syndrome for this review. We sought both parallel group and cross-over studies of children or adults, at any dose, and for any duration.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods to select studies, assess risk of bias, extract and analyse data. All authors independently abstracted data onto standardized forms; disagreements were resolved by mutual discussion.

MAIN RESULTS

Only one randomised placebo-controlled, double-blind cross-over study met our selection criteria. In this study, 20 participants with motor tics were enrolled over a three-year recruitment period; 18 (14 of whom had a diagnosis of Tourette's syndrome) completed the study; in total, 21 focal motor tics were treated. Although we considered most bias domains to be at low risk of bias, the study recruited a small number of participants with relatively mild tics and provided limited data for our key outcomes. The effects of botulinum toxin injections on tic frequency, measured by videotape or rated subjectively, and on premonitory urge, are uncertain (very low-quality evidence). The quality of evidence for adverse events following botulinum toxin was very low. Nine people had muscle weakness following the injection, which could have led to unblinding of treatment group assignment. No data were available to evaluate whether botulinum injections led to immunoresistance to botulinum.

AUTHORS' CONCLUSIONS

We are uncertain about botulinum toxin effects in the treatment of focal motor and phonic tics in select cases, as we assessed the quality of the evidence as very low. Additional randomised controlled studies are needed to demonstrate the benefits and harms of botulinum toxin therapy for the treatment of motor and phonic tics in patients with Tourette's syndrome.

Treatment-refractory Tourette Syndrome

Tourette Syndrome (TS) is a complex neurodevelopmental condition marked by tics and frequently associated with psychiatric comorbidities. While most cases are mild and improve with age, some are treatment-refractory. Here, we review strategies for the management of this population. We begin by examining the diagnosis of TS and routine management strategies. We then consider emerging treatments for refractory cases, including deep brain stimulation (DBS), electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (rTMS), and novel pharmacological approaches such as new vesicular monoamine transporter type 2 inhibitors, cannabinoids, and anti-glutamatergic drugs.

European clinical guidelines for Tourette syndrome and other tic disorders. Part II: pharmacological treatment

To develop a European guideline on pharmacologic treatment of Tourette syndrome (TS) the available literature was thoroughly screened and extensively discussed by a working group of the European Society for the Study of Tourette syndrome (ESSTS). Although there are many more studies on pharmacotherapy of TS than on behavioral treatment options, only a limited number of studies meets rigorous quality criteria. Therefore, we have devised a two-stage approach. First, we present the highest level of evidence by reporting the findings of existing Cochrane reviews in this field. Subsequently, we provide the first comprehensive overview of all reports on pharmacological treatment options for TS through a MEDLINE, PubMed, and EMBASE search for all studies that document the effect of pharmacological treatment of TS and other tic disorders between 1970 and November 2010. We present a summary of the current consensus on pharmacological treatment options for TS in Europe to guide the clinician in daily practice. This summary is, however, rather a status quo of a clinically helpful but merely low evidence guideline, mainly driven by expert experience and opinion, since rigorous experimental studies are scarce.

An overview of the treatment of Tourette's disorder and tics

OBJECTIVE

The aim of this study was to review the efficacy of various treatments for Tourette's disorder (TD) and tics.

METHOD

This study is a historical review of the treatment modalities prior to the advent of neuroleptics. A review of double-blind and placebo-controlled clinical trials and open studies on the use of neuroleptics and selected reports was also carried out.

RESULTS

The literature review reveals that the treatment of TD and tics has evolved from an early history of marginally effective approaches to the advent of neuroleptics, which started a new era in TD and tic treatment, with a significantly broader range of effectiveness.

CONCLUSIONS

Although progress has been made, the literature review nevertheless reveals a great deal of confusion as related to the clinical heterogeneity of TD and tics, differences in populations, medication-dose combinations, and outcomes. However, a role for a limited number of pharmacologic agents, combined with psychosocial approaches, has been identified. There is a need for studies in larger, diagnostically homogenous samples and for the use of more sophisticated methodology, to identify intelligible models that would allow the development of more effective treatment approaches.

Tic suppression: the medical model

Tics are intermittent, repetitive, patterned but usually nonrhythmic motor movements or sounds performed in response to urges or involuntarily. They are the cardinal symptom required for a DSM-IV-TR diagnosis of Tourette's disorder (TD). Many children with TD present with mild tics that cause no significant impairment. However, when tics cause pain or interference, medical treatment is reasonable. This article reviews current evidence for treatment of tics in TD with medications as well as deep brain stimulation and transcranial magnetic stimulation. It concludes with some context for understanding this literature, relevant to treatment decisions and future treatment research in TD.

The management of tics

A tic is a stereotyped repetitive involuntary movement or sound, frequently preceded by premonitory sensations or urges. Most tic disorders are genetic or idiopathic in nature, possibly due to a developmental failure of inhibitory function within frontal-subcortical circuits modulating volitional movements. Currently available oral medications can reduce the severity of tics, but rarely eliminate them. Botulinum toxin injections can be effective if there are a few particularly disabling motor tics. Deep brain stimulation has been reported to be an effective treatment for the most severe cases, but remains unproven. A comprehensive evaluation accounting for secondary causes, psychosocial factors, and comorbid neuropsychiatric conditions is essential to successful treatment of tic disorders.

Movement disorder emergencies

Movement disorder emergencies include any movement disorder which evolves over hours to days, in which failure to appropriately diagnose and manage can result in patient morbidity or mortality. It is crucial that doctors recognize these emergencies with accuracy and speed by obtaining the proper history and by being familiar with the phenomenology of frequently encountered movements. These disorders will be discussed based on the most common associated involuntary movement, either parkinsonism, dystonia, chorea, tics or myoclonus, and, when available, review the workup and treatment options based on the current literature.

Botulinum toxin in the management of laryngeal tics

SUMMARY

The objective of the study was to demonstrate the utility of botulinum toxin (BTX; Botox: Allergan Pharmaceuticals, Irvine, CA) type A injections for symptom reduction in laryngeal tics. The study consisted of case studies and literature review. Case histories of two patients with laryngeal tics are presented. Treatment was administered using BTX type A injected into the thyroarytenoid muscles using electromyographic guidance or via direct laryngoscopy. Treatment outcomes were measured using clinical rating scales with a range from 0 (no response) to 4 (maximal response). A subjective assessment of reduction in premonitory sensations was recorded. Subject 1 was a 49-year-old female with onset of laryngeal tic (throat clearing) at 46 years. She received six injections over 24 months. The lowest effective dose was 1.25 units bilaterally, producing complete resolution of the tic behavior (peak effect of 4/4) and reduction of the premonitory sensations. The median duration of benefit was 13 weeks. Subject 2 was a 14-year-old male with Gilles de la Tourette syndrome with laryngeal symptoms including throat clearing, barking, and crowing. He received three injections, with the lowest effective dose of 0.625 units bilaterally. He achieved marked reduction (peak effect of 3/4) of the throat clearing, barking, and crowing behaviors. There was also substantial reduction of the premonitory sensations. The median duration of benefit was 10 weeks. The cases presented herein are examples of successful treatment with low-dose BTX type A to reduce the symptoms of laryngeal tics, leading to improved quality of life. These cases add to the relatively small number of similar patients reported in the literature, and support the use of chemical neuromuscular blockade for treatment of laryngeal tic symptoms.

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.

Botulinum toxin-physiology and applications in head and neck disorders

This article is structured around a literature review that was carried out using Ovid and Medline with the key words "botulinum," "toxin," and "ENT." Botulinum toxin has been used safely in humans for more than 20 years. The effects are transient, such that treatments are required to be repeated at intervals. Its application to ENT provides a useful tool to treat dystonia, autonomic dysfunction, facial nerve paresis, and hyperfunctional lines. It may also be of benefit in laryngeal rebalancing and the treatment of headaches. Further research is being carried out and new indications for treatment with botulinum toxin may include sialorrhea and rhinorrhea.

Movement disorder emergencies

For the past 4 years, Dr. Stanley Fahn and I have given a course at the American Academy of Neurology annual meeting on the topic of movement disorder emergencies. The purpose of this review article is to summarize the topic and to present it to readers of this journal. The text of this article has appeared in nearly the same form as the Academy syllabus accompanying our course. It is being presented here so that readers of the journal may review the material.

Noncosmetic uses of botulinum toxin

In conclusion, botulinum toxin usage over the past 2 to 3 decades has expanded exponentially. Almost every discipline in medicine has found some therapeutic use for this toxin. Botulinum toxin has been shown to be safe, effective, and relatively easy to administer with proper training.

[Palatal myoclonus and dysphagia]

INTRODUCTION

Post brainstem lesion dysphagia is frequently associated with palatal myoclonus (PM) but the correlation between these two symptoms is still unclear.

OBJECTIVE

The aim of this study was to verify the relationship between PM and dysphagia, and if PM could itself induce dysphagia.

PATIENTS AND METHODS

Twelve patients suffering from post brainstem lesion PM and dysphagia; 10 male and two female, mean aged of 50.5 years, were assessed using clinical examination, radiological and endoscopic examination of deglutition.

RESULTS

In three cases, PM were associated with pharyngeal area decreasing, laryngeal aspiration, and dysphagia.

DISCUSSION

This study confirms the hypothesis of close relationship between PM and dysphagia. In these cases, specific dysphagia therapy should be recommended.

CONCLUSION

Post brainstem lesion dysphagia is sometimes associated with PM and in some cases, there is probably a relationship between PM and swallowing disorders of these patients.

Noncosmetic uses of botulinum toxin

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.

Pharmacological management of tics in patients with TS

This article reviews the evidence published in the English language literature concerning the pharmacological treatment of tics in patients with Tourette Syndrome. The focus is on the efficacy and safety of the current treatments. A clinical approach to pharmacological management of Tourette Syndrome patients is outlined.

Pharmacological options for the treatment of Tourette's disorder

Tourette's disorder is a neuropsychiatric disorder characterised clinically by motor and vocal tics, which may be associated to conductual disorders such as obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD). Although the neurochemistry of Tourette's disorder is not well known, there are some effective therapies for tics, OCD and ADHD. However, these are not devoid of adverse effects. Tics only require treatment when they interfere with the functioning of the patient. If therapy is needed, monotherapy at the minimal effective dose is desirable, but some patients may require two or more drugs. The most frequently used drugs for tics are antipsychotics (mainly pimozide and haloperidol) and clonidine. The potential usefulness of atypical antipsychotic drugs (risperidone, olanzapine, clozapine, ziprasidone) and other dopaminergic drugs (fluphenazine, sulpiride, tiapride, metoclopramide, piquindone, tetrabenazine), clonazepam, calcium channel antagonists, botulinum toxin, dopamine agonists, selegiline, and other drugs is discussed. The drugs of choice for OCD in patients with Tourette's disorder are the selective serotonin reuptake inhibitors (SSRIs), although the tricyclic antidepressant clomiplamine, which inhibits both serotonin and noradrenaline uptake, has also been found to be useful. ADHD can be treated with some psychostimulants, mainly methylphenidate, although these drugs must be used with caution. Other potentially useful drugs for the treatment of ADHD in patients with Tourette's disorder are clonidine, guanfacine, selegiline, some tricyclic antidepressants, sertraline, pimozide and clonazepam. Finally, the potential value of some nonpharmacological therapies (hypnotherapy, biofeedback, conductual therapies, electroconvulsive therapy, acupuncture and surgery) is briefly reviewed.

Botulinum toxin: basic science and clinical uses in otolaryngology

The role of botulinum toxin as a therapeutic agent is expanding rapidly in otolaryngology. Botulinum toxin is a protease that blocks the release of acetylcholine from nerve terminals. Its effects are transient and nondestructive, and largely limited to the area in which it is administered. These effects are also graded according to dose, allowing for individualized treatment of patients and disorders. Botulinum toxin has been used primarily to treat disorders of excessive or inappropriate muscle contraction. In the field of otolaryngology, these include spasmodic dysphonia, oromandibular dystonia, and blepharospasm; vocal tics and stuttering; cricopharyngeal achalasia; various tremors and tics; hemifacial spasm; temporomandibular joint disorders; and a number of cosmetic applications. Botulinum toxin treatment has recently begun to show some benefit in the control of pain from migraine and tension headache. It may also prove useful in the control of autonomic dysfunction, as in Frey syndrome, sialorrhea, and rhinorrhea. In over 20 years of use in humans, botulinum toxin has accumulated a considerable safety record, and in many cases represents relief for thousands of patients unaided by other therapy.