Sonographic detection of basal ganglia abnormalities in spasmodic dysphonia.

BACKGROUND AND PURPOSE: Abnormalities of the lenticular nucleus (LN) on transcranial sonography (TCS) are a characteristic finding in idiopathic segmental and generalized dystonia. Our intention was to study whether TCS detects basal ganglia abnormalities also in spasmodic dysphonia, an extremely focal form of dystonia. METHODS: Transcranial sonography of basal ganglia, substantia nigra and ventricles was performed in 14 patients with spasmodic dysphonia (10 women, four men; disease duration 16.5 ± 6.1 years) and 14 age- and sex-matched healthy controls in an investigator-blinded setting. RESULTS: Lenticular nucleus hyperechogenicity was found in 12 spasmodic dysphonia patients but only in one healthy individual (Fisher's exact test, P < 0.001) whilst other TCS findings did not differ. The area of LN hyperechogenic lesions quantified on digitized image analysis correlated with spasmodic dysphonia severity (Spearman test, r = 0.82, P < 0.001). CONCLUSION: Our findings link the underlying pathology of spasmodic dysphonia to that of more widespread forms of dystonia.

Spasmodic dysphonia and botulinum toxin: experience from the largest treatment series.

Spasmodic dysphonia is a focal laryngeal dystonia, with adductor, abductor, mixed, respiratory and singer's types. Our series over 24 years includes 1300 patients. 82% are of the adductor type; 63% were female; 12% had a positive family history and 82.4% had a focal distribution. All of the patients were managed with varying degrees of success with individualised dosing of botulinum neurotoxin A injected into the laryngeal musculature under EMG guidance.

Novel THAP1 sequence variants in primary dystonia.

BACKGROUND: THAP1 encodes a transcription factor (THAP1) that harbors an atypical zinc finger domain and regulates cell proliferation. An exon 2 insertion/deletion frameshift mutation in THAP1 is responsible for DYT6 dystonia in Amish-Mennonites. Subsequent screening efforts in familial, mainly early-onset, primary dystonia identified additional THAP1 sequence variants in non-Amish subjects. OBJECTIVE: To examine a large cohort of subjects with mainly adult-onset primary dystonia for sequence variants in THAP1. METHODS: With high-resolution melting, all 3 THAP1 exons were screened for sequence variants in 1,114 subjects with mainly adult-onset primary dystonia, 96 with unclassified dystonia, and 600 controls (400 neurologically normal and 200 with Parkinson disease). In addition, all 3 THAP1 exons were sequenced in 200 subjects with dystonia and 200 neurologically normal controls. RESULTS: Nine unique melting curves were found in 19 subjects from 16 families with primary dystonia and 1 control. Age at dystonia onset ranged from 8 to 69 years (mean 48 years). Sequencing identified 6 novel missense mutations in conserved regions of THAP1 (G9C [cervical, masticatory, arm], D17G [cervical], F132S [laryngeal], I149T [cervical and generalized], A166T [laryngeal], and Q187K [cervical]). One subject with blepharospasm and another with laryngeal dystonia harbored a c.-42C>T variant. A c.57C>T silent variant was found in 1 subject with segmental craniocervical dystonia. An intron 1 variant (c.71+9C>A) was present in 7 subjects with dystonia (7/1,210) but only 1 control (1/600). CONCLUSIONS: A heterogeneous collection of THAP1 sequence variants is associated with varied anatomical distributions and onset ages of both familial and sporadic primary dystonia.

Assessment: Botulinum neurotoxin for the treatment of movement disorders (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

OBJECTIVE: To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in the treatment of movement disorders. METHODS: A literature search was performed including MEDLINE and Current Contents for therapeutic articles relevant to BoNT and selected movement disorders. Authors reviewed, abstracted, and classified articles based on American Academy of Neurology criteria (Class I-IV). RESULTS: The highest quality literature available for the respective indications was as follows: blepharospasm (two Class II studies); hemifacial spasm (one Class II and one Class III study); cervical dystonia (seven Class I studies); focal upper extremity dystonia (one Class I and three Class II studies); focal lower extremity dystonia (one Class II study); laryngeal dystonia (one Class I study); motor tics (one Class II study); and upper extremity essential tremor (two Class II studies). RECOMMENDATIONS: Botulinum neurotoxin should be offered as a treatment option for the treatment of cervical dystonia (Level A), may be offered for blepharospasm, focal upper extremity dystonia, adductor laryngeal dystonia, and upper extremity essential tremor (Level B), and may be considered for hemifacial spasm, focal lower limb dystonia, and motor tics (Level C). While clinicians' practice may suggest stronger recommendations in some of these indications, evidence-based conclusions are limited by the availability of data.

The emerging role of botulinum toxin in the treatment of temporomandibular disorders.

The objective of this review was to discuss the emerging role of botulinum toxin in the treatment of temporomandibular disorders (TMD), to review the current literature, recent clinical trials, as well as preliminary data from our own clinical study, and to formulate an algorithm for the work-up and treatment of TMD.

Vocal fold paresis of Charcot-Marie-Tooth disease.

No cohesive overview of vocal fold abnormalities associated with Charcot-Marie-Tooth disease (CMT) has been presented in the literature. This study examines a patient in depth and compares the findings with those of published reports to characterize the features of vocal fold paresis in CMT. The affected patient was investigated with nerve conduction testing, laryngeal electromyography, endoscopy, and laryngeal sensory testing. Ten published cases were reviewed for similarities and differences. Vocal fold paresis has been observed in 11 CMT patients ranging in age from 8 to 80 years. Two cases have occurred in the context of CMT type 1, and 9 in CMT type 2. Seven of the 11 cases (64%) were clearly bilateral; only 2 of the 7 cases (29%) required tracheotomy, and both were in children. The electromyographic findings were typical of reinnervation. Sensory findings were present, but did not represent significant disability in the 1 patient so studied. We conclude that CMT does not spare the cranial nerves, as has been previously thought. Furthermore, vocal fold paresis is not restricted to CMT type 2 and should not be considered a hallmark of that category. The available evidence suggests that the neural deficit evolves gradually, may exhibit partial recovery, and often escapes notice for a time. Vocal fold abnormalities are most often bilateral. Because the deficit is generally well tolerated in adults, many cases have probably been overlooked, and no conclusion regarding incidence is possible. Nevertheless, the potential for airway compromise exists, especially in children. Respiratory complaints of CMT patients should be thoroughly investigated.

Other noncosmetic uses of BOTOX.

Botulinum toxin A has a wide variety of clinical applications, which are related by blockade of acetylcholine and often are related to abnormal muscle contractures. These applications include ocular disorders, disorders of the upper aerodigestive tract, dystonia and hemifacial spasm, cosmetic, gastrointestinal disorders, genitourinary disorders, management of pain, and use in autonomic nervous system disorders. Many of these diseases will be discussed with regard to their treatment with botulinum toxin compared to conventional treatments. Advantages and disadvantages of botulinum toxin use are delineated. General guidelines for adult and pediatric dosing will also be discussed.

Botulinum toxin type A (BOTOX) for treatment of migraine.

An open-label study and 2 double-blind, placebo-controlled studies have provided supporting evidence of botulinum toxin type A (BTX-A) as an effective, well-tolerated treatment for migraine. Observed durations of benefit were consistent with known properties of BTX-A. Findings suggest that response may vary by features of preinjection headaches, such as migraine frequency. The precise mechanism by which BTX-A provides pain relief is hypothesized to be related not only to acetylcholine inhibition but also to a blocking action on the parasympathetic nervous system. Additional studies that control factors likely to be related to response may lead to better understanding of the BTX-A effect on migraine and an optimal treatment protocol.

Current practices in the use of botulinum toxin A in the management of facial lines and wrinkles.

Botulinum toxin A (BTX-A) is a potent neurotoxin produced by the bacterium Clostridium botulinum. There are eight antigenically distinct serotypes, and they share a similar structure--a light chain with an associated molecule of zinc and a heavy chain linked by a disulfide bond. Each serotype has a separate site of action within the nerve ending. Only serotype A (Botox, Allergan, Irvine, CA) is available for clinical use in the United States.

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.

Botulinum toxin type A (BOTOX) for treatment of migraine headaches: an open-label study.

OBJECTIVE: The object of this clinical experience was to evaluate the correlation between pericranial botulinum toxin type A (BOTOX, Allergan Corp, Irvine, CA) administration and alleviation of migraine headache symptoms. STUDY DESIGN AND SETTING: A nonrandomized, open-label study was performed at 4 different test sites. The subjects consisted of 106 patients, predominantly female, who either (1) initially sought BOTOX treatment for hyperfunctional facial lines or other dystonias with concomitant headache disorders, or (2) were candidates for BOTOX treatment specifically for headaches. Headaches were classified as true migraine, possible migraine, or nonmigraine, based on baseline headache characteristics and International Headache Society criteria. BOTOX was injected into the glabellar, temporal, frontal, and/or suboccipital regions of the head and neck. Main outcome measures were determined by severity and duration of response. The degrees of response were classified as: (1) complete (symptom elimination), (2) partial > or =50% reduction in headache frequency or severity), and (3) no response [neither (1) nor (2)]. Duration of response was measured in months for the prophylactic group. RESULTS: Among 77 true migraine subjects treated prophylactically, 51% (95% confidence interval, 39% to 62%) reported complete response with a mean (SD) response duration of 4.1 (2.6) months; 38% reported partial response with a mean (SD) response duration of 2.7 (1.2) months. Overall improvement was independent of baseline headache characteristics. Seventy percent (95% confidence interval, 35% to 93%) of 10 true migraine patients treated acutely reported complete response with improvement 1 to 2 hours after treatment. No adverse effects were reported. CONCLUSIONS: BOTOX was found to be a safe and effective therapy for both acute and prophylactic treatment of migraine headaches. Further research is needed to explore and develop the complete potential for the neuroinhibitory effects of botulinum toxin.

Botulinum toxin for the treatment of spasmodic dysphonia.

Spasmodic dysphonia is a focal laryngeal dystonia. Laryngeal dystonia presents as: adductor spasmodic dysphonia with the characteristic strain-strangle voice; abductor spasmodic dysphonia with hypophonia and breathy breaks in connected speech; and adductor respiratory dystonia with paradoxical vocal fold motion and intermittent stridor. Current treatment with periodic laryngeal intramuscular injections of botulinum toxin A has allowed patients to function more normally. In this article, the authors' treatment paradigm and experience in treating over 900 patients with laryngeal dystonia are discussed.

Botulinum toxin treatment for symptomatic Frey's syndrome.

Gustatory sweating, or Frey's syndrome, usually occurs after surgery or trauma to the parotid gland as a result of inappropriate parasympathetic cholinergic innervation of cutaneous sympathetic receptors. Numerous medical and surgical treatments have been proposed to prevent or treat this condition. The results, overall, have been unsatisfactory. Botulinum toxin is a relatively new treatment modality for Frey's syndrome. We review the literature and present our experience with 7 patients successfully treated with intradermal injections of botulinum toxin (Botox). Our technique and dosing are described. In all treated patients gustatory sweating ceased in the area injected with botulinum toxin. In 6 patients, symptoms reappeared, and additional injections were needed up to 4 times, at 6- to 8-month intervals. All patients now have been free of symptoms for a long period of time (mean 12.1 months). We strongly recommend intradermal injections of botulinum toxin as a safe, efficacious treatment for gustatory sweating.

Evaluation and management of bilateral vocal cord immobility.

Bilateral vocal cord immobility can be life threatening for some patients. Others, who have an open glottic chink, may have a breathy dysphonia, intermittent dyspnea, and stridor. These signs and symptoms may also be found in a number of other conditions that cause weakness or paradoxical motion of the vocal cords that mimics paralysis. These other conditions include central nervous system diseases, neuromuscular disorders, laryngospasm, and psychogenic disorders. In addition, patients with cricoarytenoid joint immobility or interarytenoid scar can also have similar symptoms at presentation. It is critical to consider the differential diagnosis of an assumed bilateral vocal cord paralysis and understand the management of paradoxical movement, weakness, joint fixation, interarytenoid scar, laryngospasm, and psychogenic disorders. The treatment for bilateral immobility should proceed only after a thorough evaluation, which might include electromyography and/or examination during general anesthesia under dense anesthetic paralysis. Reconstructive procedures are the treatments of choice, and destructive procedures should be chosen only as a last resort.

Treatment of hyperfunctional lines of the face with botulinum toxin A.

Since Botulinum toxin A became a mainstay therapy for blepharospasm, its use in treating other dystonic conditions, spasticity disorders, as well as hyperfunctional lines of the face has increased exponentially in recent years. The following article summarizes our experience in establishing a safe and reliable method of administration of botulinum toxin A for treating hyperfunctional lines of the face.

Botulinum toxin management of spasmodic dysphonia (laryngeal dystonia): a 12-year experience in more than 900 patients.

OBJECTIVES: This paper reviews a 12-year experience in more than 900 patients with spasmodic dysphonia who have been treated with botulinum toxin. STUDY DESIGN: This is a retrospective analysis of patients with adductor spasmodic dysphonia (strain-strangled voice), abductor spasmodic dysphonia (whispering voice), and adductor breathing dystonia (paradoxical vocal fold motion), all of whom have been treated with botulinum toxin injections for relief of symptom. METHODS: All of the patients were studied with a complete head and neck and neurologic examination; fiberoptic laryngostroboscopy; acoustic and aerodynamic measures; and a speech evaluation including the Universal spasmodic dysphonia rating scale. Some were given electromyography. All patients received botulinum toxin injections into the affected muscles under electromyographic guidance. RESULTS: The adductor patients had an average benefit of 90% of normal function lasting an average of 15.1 weeks. The abductor patients had an average benefit of 66.7% of normal function lasting an average of 10.5 weeks. Adverse effects included mild breathiness and coughing on fluids in the adductor patients, and mild stridor in a few of the abductor patients. CONCLUSION: Botulinum toxin A injection of the laryngeal hyperfunctional muscles has been found over the past 12 years to be the treatment of choice to control the dystonic symptoms in most patients with spasmodic dysphonia.