Diagnostic and therapeutic difficulties in laryngeal dystonia

Spasmodic dysphonia is a focal laryngeal dystonia. It presents as: adductor spasmodic dysphonia with the strain-strangle voice; abductor spasmodic dysphonia with whispering voice and breathy breaks in connected speech; and adductor respiratory dystonia with paradoxical vocal fold movements and stridor. It is most commonly treated by the intramuscular injection of botulinum toxin. In this article, the authors discuss difficulties in making diagnosis and treatment in patients with laryngeal dystonia concerning their own cases.     

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 (strainstrangled 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. Laryngoscope, 108:1435–1441, 1998     

Localized injections of botulinum toxin for the treatment of focal laryngeal dystonia (spastic dysphonia)

Spastic dysphonia is a condition producing a strain-strangle phonation. We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing. The initial success of recurrent nerve section in many of these patients has been followed by recurrence of symptoms in months to years. Bilateral involvement of the vocal cords with hyperfunction of the nonparalyzed vocal cord could explain these failures. Injection of botulinum toxin (BOTOX) has been effective treatment for many focal dystonias. We have treated more than 100 patients with dystonia including five with laryngeal dystonia. All of the patients laryngeal had dramatic improvement after 48 to 72 hours; benefit lasted 3 to 9 months for each injection period. BOTOX injection can be performed on awake, ambulatory patients. Bilateral treatment and titration of dose can achieve the desired degree of weakness.     

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.     

Spasmodic dysphonia: An overview of clinical features and treatment options

Spasmodic dysphonia (SD) is considered a rare focal laryngeal dystonia characterized by task-specific voice dysfluency resulting from selective intrinsic laryngeal musculature hyperfunction. Symptoms may be attenuated by a sensory trick. Although SD can be seen at times in generalized dystonia syndrome, it is typically a sporadic phenomenon, and the involvement of the laryngeal adductor muscles is more common than that of the abductor muscles. This research reviews the literature for the pathogenesis, clinical characteristics, treatment options, and current management methods of SD. Technological advances have enabled clinicians to better understand the connection between laryngeal function and dysfunction. Refinements in imaging and genetic investigation techniques have helped better understand the underlying mechanisms of this neurolaryngology disorder. Currently, the standard of care for SD is the symptomatic management of botulinum toxin (BT) chemodenervation. This is supported by a large body of literature attesting to its efficacy in many different research studies, particularly in the uncomplicated adductor form of the disorder. Efforts towards surgical treatment predate the development of BT treatment by a decade, but the long-term efficacy has not been proven and, further research is expected. Symptom relief in patients with abductor SD and dystonia with tremors after surgical and BT treatments and those in patients remains suboptimal.     

Results of using botulism toxin in the treatment of spasmodic dysphonia

Spasmodic Dysphonia (SD) is a dystonia involving laryngeal musculature thus causing a characteristic voice disorder. Two main types of SD have been described. The adductor type is the commonest and it is characterized by a strain-strangle, choked voice. The abductor type can be distinguished from the previous one by episodes of a blown and whispering voice, interrupting speech. Botulism toxin (BTX) has demonstrated to be the most effective treatment for this condition. Thirty patients diagnosed of SD (twenty-nine adductor type/one abductor type) were included. Their degree of dysphonia was evaluated using both functional and visual-analogue scales. They were treated with BTX vocal cord injections using a percutaneous technique under EMG guidance. Improvements up to a 100% of the normal vocal function were obtained, with an average of 82% in the adductor type. The adverse effects were mild and transient. Hypophonia affected 61.3% of patients lasting an average of 11.3 days. Dysphagia was reported in 44.1% of cases lasting an average of 5.8 days.     

痉挛性发音障碍诊断及治疗的研究

目的对痉挛性发音障碍患者临床特点,喉肌电图表现,疗效进行分析,探讨痉挛性发音障碍诊断及治疗特点。方法对22例痉挛性发音障碍患者治疗前后症状、嗓音声学特征,频闪喉镜下声带状态,喉肌电图特征进行分析;根据不同分型,应用肉毒素A行特定肌肉注射并观察疗效。结果22例痉挛性发音障碍患者中,内收肌型18例(81 8% ),外展肌型4例(18 2% )。内收肌型患者发音嘶哑,音质紧张、言语中断,发音时声带过度内收,杓间区明显,伴局部震颤; 2例患者发音时还同时伴有舌及软腭震颤;肌电图甲杓肌运动单位电位(motorunitpotential,MUP)振幅明显增加(P<0 01),干扰相呈密集束状放电,募集活动异常活跃,幅度明显增大(700~2500μV)。4例外展肌型患者发音低哑、震颤,气息声明显,发音时声门闭合不良;环杓后肌MUP振幅明显增加,在374~538μV间,募集活动异常活跃,幅度增大(3000~5000μV)。内收肌型患者应用肉毒素A进行甲杓肌注射,单侧剂量大于2 5U疗效明显。症状开始改善时间为注射后6h~2d,平均( x±s,下同)为( 1 4±0 8)d, 2周时最为明显,肌电图及喉肌诱发电位显示药物作用完全,注射肌肉失神经支配。疗效维持8~24周,平均维持(15 2±4 9)周,副作用包括不同程度的发音气息声,声门闭合不良,吞咽不适,饮水呛咳。外展肌型患者采用环杓后肌     

Listening: the key to diagnosing spasmodic dysphonia

Spasmodic dysphonia (SD) is a focal dystonia of the larynx. Adductor spasmodic dysphonia (ADSD) involves the laryngeal adductor muscles, and symptoms of vocal roughness, staccato-like sounds, and stops in phonation. Abductor spasmodic dysphonia (ABSD) affects the laryngeal abductor muscles, resulting in a breathy or whispered voice quality and voice breaks. SD has a significant impact on the quality of life. This article discusses symptoms of SD and the standard treatment of SD.     

Findings of multiple muscle involvement in a study of 214 patients with laryngeal dystonia using fine-wire electromyography

Although perceptual and stroboscopic data help in diagnosing and classifying laryngeal dystonia, these measures do not aid the voice clinician in targeting which specific muscles to treat with botulinum toxin. Most patients achieve smoother, less effortful voicing with standard injection regimens. However, there is a notable failure rate. We performed fine-wire electromyography on 214 consecutive patients with laryngeal dystonia. We correlated voice ratings, stroboscopy data, and fine-wire electromyography data. Videostroboscopy was successful in visually demonstrating most of the audible findings in isolated vocal tremor, but it was much less successful in identifying breaks alone or a combination of breaks and tremor. Fine-wire electromyography revealed that the thyroarytenoid muscle was significantly more likely than the lateral cricoarytenoid muscle to be the predominant muscle associated with adductor spasmodic dysphonia, and that the thyroarytenoid and lateral cricoarytenoid muscles were equally likely to be predominantly involved in tremor spasmodic dysphonia. In addition, several patients in both the adductor spasmodic dysphonia and the tremor spasmodic dysphonia groups presented with interarytenoid muscle predominance. All of the intrinsic laryngeal muscles are capable of being the predominant muscle in laryngeal dystonia, and there are patterns of muscle abnormalities that differ between adductor spasmodic dysphonia and tremor spasmodic dysphonia. Some of the failures in treating adductor spasmodic dysphonia with botulinum toxin, and the greater difficulty with success in treating patients with tremor spasmodic dysphonia, are due to failure to deliver toxin to the appropriate muscles.     

Spasmodic laryngeal dyspnea: a rare manifestation of laryngeal dystonia

We describe clinical experiences in the management of three patients with laryngopharyngeal dystonia causing severe breathing problems. In contrast to spasmodic dysphonia, which presents with action-induced involuntary spasms of laryngeal muscles during speaking, all three patients showed laryngopharyngeal spasms primarily during respiration. In analogy to spasmodic dysphonia we propose the term spasmodic laryngeal dyspnea for this rare condition. Localized unilateral botulinum toxin injected into the thyroarytenoid muscle and /or ventricular folds reduced the quantity and quality of spasms and led to a pronounced improvement of breathing problems.     

Abductor laryngeal dystonia: a series treated with botulinum toxin.

Abductor laryngeal dystonia (LD) is characterized by a hoarse voice quality which is broken up by breathy or whispered portions. Botulinum toxin injection (Botox) has been a safe and effective treatment for adductor laryngeal dystonia and is currently accepted medical therapy. As an extension of the established treatment program, in 1989 treatment of abductor LD was initiated. Thirty-two patients have been treated by sequential percutaneous electromyogram-guided (EMG) injections of the posterior cricoarytenoid (PCA) muscles. Most patients required treatment of both PCA muscles and improved to an average of 70% of normal voice. Patients who had a preexisting tremor, evidence of dystonia in other muscle groups, vocal tremor, or respiratory dysrhythmia had less improvement. Ten patients also required injection of the cricothyroid muscles and/or type I laryngoplasty.     

Treatment of adductor laryngeal breathing dystonia with botulinum toxin type a

Adductor laryngeal breathing dystonia (ALBD) is a rare disorder in which patients have persistent inspiratory stridor, usually normal voice, and cough. Physical exam is characterized by paradoxical movement of the vocal cords on inspiration. These patients have involuntary action-induced spasms of the adductor laryngeal muscles on inspiration. There has been no uniformly satisfactory treatment for the disease. Speech therapy, psychotherapy, and pharmacotherapy have all had limited success. We report the successful use of botulinum toxin type A in seven patients with adductor laryngeal breathing dystonia. All patients received bilateral thyroarytenoid injections. All patients had toxin effect within 72 hours, reaching maximal effect within 2 weeks with sustained improvement for an average of 13.8 weeks. Adverse effects included breathy voice and mild choking on liquids. Both resolved, on average, within 2 weeks. This retrospective study supports the safe and effective use of botulinum toxin type A in the treatment of adductor laryngeal breathing dystonia.     

Recurrent laryngeal nerve avulsion for treatment of spastic dysphonia

Treatment of spastic dysphonia by recurrent laryngeal nerve section has resulted in reproducibly good results in the early postoperative period in most patients. However, critical long-term follow-up has shown a high recurrence rate of adductor spasms by the third year after initial nerve section. A patient who developed recurring adductor spasms 1 year after nerve section was reexplored, with identification of neural regrowth into the distal segment of the recurrent laryngeal nerve. The technique of neural avulsion removing the distal nerve up to its insertion into the laryngeal muscles is described. Neural regrowth, which is just one of the possible mechanisms for recurrence of spastic dysphonia, should be prevented by this surgical modification. Twelve patients who have undergone neural avulsion primarily for spastic dysphonia are being followed up without recurrence of symptoms thus far. Although these results appear promising, this short follow-up that averages 1.5 years must be extended to firmly support these concepts.     

Singer's dystonia: first report of a variant of spasmodic dysphonia

OBJECTIVES: We discuss the phonatory characteristics of a previously undescribed focal laryngeal dystonia present in the singing voice. METHODS: We performed a retrospective chart review of 5 patients with singer's dystonia at a neurolaryngology referral center. RESULTS: Four patients reviewed demonstrated phonatory characteristics consistent with adductor spasmodic dysphonia present in their singing voice. One patient demonstrated abductor spasmodic dysphonia in the singing voice. Each patient initially exhibited normal connected speech in conversational voicing. The treatment protocol and outcome are discussed, including the use of botulinum toxin. CONCLUSIONS: Singer's dystonia is a previously undescribed neurologic disorder that should be understood by those who treat voice performers and voice disorders.     

Posterior cricoarytenoid myoplasty with medialization thyroplasty in the management of refractory abductor spasmodic dysphonia

Of the approximately 100,000 Americans with primary (idiopathic) laryngeal dystonia, 10% to 15% are thought to havethe abductor form. Botulinum A toxin injected into the posterior cricoarytenoid muscle and/or cricothyroid muscle has been employed as the "gold standard" for therapeutic management; however, successful results are significantly less frequent than with injections for the adductor form. This report describes a new phonosurgical procedure, posterior cricoarytenoid myoplasty with medialization thyroplasty, designed for these refractory patients. Posterior cricoarytenoid myoplasty with medialization thyroplasty has been performed on 3 patients with abductor laryngeal dystonia. All patients had failed at least 5 previous botulinum A injections to the posterior cricoarytenoid and cricothyroid muscles. All patients underwent preoperative and 3 postoperative (2 weeks, 3 months, and 1 year) phonatory analyses. Analysis consisted of recording an aloud reading of a standard passage while a blinded trained speech pathologist counted prolonged voiceless consonants. The patients also completed a satisfaction survey at 1 year. The results demonstrated significant, long-lasting, uniform reduction in breathy breaks in all subjects. The participants all judged their symptoms as greatly improved. Bilateral procedures may be necessary, but should be staged to prevent possible airway compromise. When applied appropriately, posterior cricoarytenoid myoplasty with medialization thyroplasty is a viable tool in the management of refractory abductor laryngeal dystonia.     

Laryngeal electromyographic activity in adductor and abductor spasmodic dysphonia

Vocal symptoms in spasmodic dysphonia (SD) range from strain-strangle phonation and glottal-stop phonatory breaks of adductor SD to breathy phonation and aspirate phonatory breaks of abductor SD. Many SD subjects show both symptom types. Heterogeneity in vocal symptoms contributes to controversy surrounding the etiology(s) of SD. Acoustic/perceptual analyses of vocal symptoms are inconclusive in resolving this controversy. This investigation moves the search for distinguishing features of adductor and abductor SD to the level of neuromuscular control and analysis of intrinsic laryngeal muscle (adductor and abductor) activity. Subjects rated perceptually as primarily adductor or abductor SD sustained production of vegetative gestures and isolated speech sounds (/i/ and /s/). Qualitative and quantitative analyses of electromyographic signals recorded from thyroarytenoid (TA) failed to differentiate SD subjects by symptom type. Analysis of TA and posterior cricoarytenoid (PCA) activity in one abductor SD revealed high levels in both muscles during production of the voiced vowel. Data suggest that a possible explanation for symptom heterogeneity in SD is the relation between disrupted neuromotor input to laryngeal muscles and reflexive or conscious compensations constrained by laryngeal biomechanics.     

Clinical and laboratory characteristics of focal laryngeal dystonia: Study of 110 cases

Spastic dysphonia is a syndrome often, producing a strain-strangle voice. We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing. In a study of 1,280 cases of dystonia registered at the Dystonia Clinical Research Center at the Columbia-Presbyterian Medical Center, we found 110 patients who had vocal cord involvement. These patients had historical information evaluated for age of onset (mean 34.6 years), duration of symptoms (mean 13.8 years), sex (1.4:1 female to male) family history (positive in 23%), and primary (66%) and secondary (34%) etiology; neurological evaluation for other dystonic involvement (25% with segmental cranial involvement, 23% with generalized dystonia) or tremor (irregular 23%, regular 6% on EMG). Treatment options were evaluated and included speech therapy, psychotherapy, biofeedback (with limited success), systemic medication (limited success except in abductor cases), nerve section (with late failure rate), and the use of botulinum toxin (improvement in all 34 injected patients).     

Treatment of the interarytenoid muscle with botulinum toxin for laryngeal dystonia

The treatment of laryngeal dystonia with botulinum toxin has provided various degrees of relief to the majority of patients with adductor dysphonia; however, a significant number of patients have limited or no improvement with this type of therapy. It remains unclear why some patients respond to the routine administration of toxin to the thyroarytenoid muscles whereas others do not. Injections into the lateral cricoarytenoid muscles have provided an improved voice in some patients who were unresponsive to injections into the thyroarytenoid muscles. Fine-wire electromyography can demonstrate the particular dystonic activity of these muscles to help determine which muscle is predominantly involved. It can also demonstrate dramatic dystonic activity in the interarytenoid (IA) muscle in many patients. We present the results of 23 patients treated with injections to the IA muscle after demonstration of dystonic IA activity. Ten have benefited from IA therapy. Five of these 10 patients did not have a good result from botulinum toxin until IA injections were added to the treatment plan. In 8 patients, IA therapy provided no improvement, and 5 patients were lost to adequate follow-up. According to fine-wire electromyography and clinical response, the IA muscle is an active dystonic muscle in some patients with laryngeal dystonia and should be treated with botulinum toxin in selected patients.     

Brainstem pathology in spasmodic dysphonia

Spasmodic dysphonia (SD) is a primary focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speech production. We examined two rare cases of postmortem brainstem tissue from SD patients compared to four controls. In the SD patients, small clusters of inflammation were found in the reticular formation surrounding solitary tract, spinal trigeminal, and ambigual nuclei, inferior olive, and pyramids. Mild neuronal degeneration and depigmentation were observed in the substantia nigra and locus coeruleus. No abnormal protein accumulations and no demyelination or axonal degeneration were found. These neuropathological findings may provide insights into the pathophysiology of SD. Laryngoscope, 2010     

Effects of adductor muscle stimulation on speech in abductor spasmodic dysphonia

OBJECTIVE: To determine whether adductor laryngeal muscle stimulation might be a beneficial treatment alternative for abductor spasmodic dysphonia (ABSD). STUDY DESIGN: Baseline comparisons were made on measures of voiceless consonant and syllable duration between patients with ABSD and normal control subjects, and speech and voice production with and without muscle stimulation were compared within 10 patients with ABSD. METHODS: Baseline group comparisons were conducted on measures of syllable and voiceless consonant duration between the patients and the control subjects. Neuromuscular stimulation was applied to the thyroarytenoid or lateral cricoarytenoid muscles in the patients during extended phonation, and measures were made of fundamental frequency and sound pressure level in the stimulated and nonstimulated conditions. Voiceless consonant duration was compared with and without adductor laryngeal muscle stimulation during syllable repetitions and sentences in the patients. RESULTS: Before stimulation, the patients had increased syllable durations in comparison with control subjects (P = .003). Repeated within-patient comparisons with and without stimulation demonstrated significant (P < .008) reductions in voiceless consonant durations during syllable repetition. The more severely affected patients had the greatest reductions in voiceless consonant duration during sentence production. CONCLUSIONS: Adductor muscle stimulation improved speech production in patients with ABSD, and the improvement was greatest in the most severely affected patients. Therefore adductor muscle stimulation has potential for benefiting patients with ABSD.