[Use of botulinum toxin in the treatment of laryngeal dystonia (spasmodic dysphonia): preliminary study of twelve patients]

Pharyngeal Motility Before and After Thyroarytenoid Muscle Botulinum Toxin Injection

Botulinum toxin type A (BTA) injection in intrinsic laryngeal musculature may result in dysphagia and consequent loss of quality of life (QOL) in a percentage of patients. This study aims to evaluate pharyngeal motility as a putative cause for this change in swallow quality in light of high-resolution manometry (HRM). Twenty patients (95% females, median age 66 years) underwent high-resolution manometry before and after BTA injection. Dysphagia was evaluated based on a QOL dedicated questionnaire (SWAL-QOL) before and after BTA injection. Pharyngeal motility at the topography of the vellum, epiglottis, and upper esophageal sphincter (UES) were recorded. Eleven (55%) subjects had worsened QOL after BTA injection. In patients with worsened QOL, UES extension decreased (p = 0.005), UES residual pressure increased (p = 0.02), UES basal pressure decreased (p = 0.04), and velopharynx contraction duration decreased (p = 0.04). UES residual pressure increased (p = 0.01), velopharynx peak pressure (p = 0.04) and upstroke (p = 0.007) decreased in patients with maintained QOL. There was no difference between groups when comparing pre-injection values. UES extension (p = 0.01) and UES maximum relaxation time (p = 0.03) was lower in the group with worsened QOL after BTA as compared to no change in QOL. Pharyngeal motility as measured by HRM was not a predictor for post procedure dysphagia and the changes in motility after BTA injection does not seem to be a strong contributor to dysphagia.

Use of botulinum toxin for movement disorders

The term movement disorders encompasses all disorders hypokinetic and hyperkinetic, which were previously known as extrapyramidal syndromes. With the definition of movement disorders and their diagnostic criteria and classifications, new studies for therapeutics could be performed. New drugs were launched, functional neurosurgery was developed, and the introduction of botulinum toxin (BoNT) for hyperkinesias was introduced. BoNT is an important therapy for dystonia, tics, myoclonus, and tremors. The aim of this review is to present the new and well-established uses of BoNT for movement disorders.

Persistent developmental stuttering as a cortical-subcortical dysfunction: evidence from muscle activation

BACKGROUND: One contemporary view of stuttering posits that speech disfluencies arise from anomalous speech motor control. PURPOSE: To verify the rest muscle tension and speech reaction time of fluent and stuttering adults. METHOD: 22 adults, divided in two groups: G1 - 11 fluent individuals; G2 - 11 stutterers. Electromyography recordings (inferior orbicularis oris) were collected in two different situations: during rest and in a reaction time activity. RESULTS: The groups were significantly different considering rest muscle tension (G2 higher recordings) and did not differ when considering speech reaction time and muscle activity during speech. There was a strong positive correlation between speech reaction time and speech muscle activity for G2 - the longer the speech reaction time, the higher the muscle activity during speech. CONCLUSION: In addition to perceptible episodes of speech disfluency, stutterers exhibit anomalies in speech motor output during fluent speech. Correlations with a possible cortical-subcortical disorder are discussed.

Laryngeal dystonia: case report and treatment with botulinum toxin

Laryngeal dystonia or spasmodic dysphonia is characterized by involuntary and inappropriate spasms of vocal muscles, having the adductor type as the most common one. It is characterized by strain-strangled voice with pitch breaks. Diagnosis is made by means of videolaryngostroboscopic exam. The treatment of choice is done with botulinum toxin directly injected in the muscles responsible for the mismatched movement. The aim of this study is to report on an adductor- type dysphonia patient and to discuss the advantages and observations about this treatment reported in the literature.

Botulinum toxin injections for the treatment of spasmodic dysphonia

BACKGROUND

The use of botulinum toxin for the treatment of spasmodic dysphonia is currently the treatment of choice for management of this neurological voice disorder. Over the past 20 years, botulinum toxin has been used to treat both adductor and abductor forms of the disorder, with vocal improvement noted after treatment for both. A large number of studies have attempted to document the efficacy of botulinum toxin for improvement of vocal symptoms in individuals with spasmodic dysphonia.

OBJECTIVES

To determine the effectiveness of botulinum toxin for treating spasmodic dysphonia.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to July 2003), EMBASE (1974 to July 2003 ), CINAHL (through July 2003), Dissertation Abstracts International (1975 to July 2003) and PsycINFO (1975 to July 2003). The search engine FirstSearch was also used (July 2003). Reference lists for all the obtained studies and other review articles were examined for additional studies.

SELECTION CRITERIA

All studies in which the participants were randomly allocated prior to intervention and in which botulinum toxin was compared to either an alternative treatment, placebo or non-treated control group were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated all potential studies meeting the selection criteria noted above for inclusion. One study met the inclusion criteria and was included in the final analysis.

MAIN RESULTS

Only one study in the literature met the inclusion criteria. This was the only study identified which reported a treatment/no treatment comparison. It reported significant beneficial effects for fundamental frequency (Fo), Fo Range, spectrographic analysis, independent ratings of voice severity and patient ratings of voice improvement.

REVIEWERS' CONCLUSIONS

The evidence from randomized controlled trials does not allow firm conclusions to be drawn about the effectiveness of botulinum toxin for all types of spasmodic dysphonia, or for patients with different behavioral or clinical characteristics.