- Author: Michael J Pitman, MD; Chief Editor: Arlen D Meyers, MD, MBA more...
Spasmodic dysphonia (SD) remains one of the most inveterate dysphonias despite various attempts to treat the disease. Because the cause of spasmodic dysphonia (SD) is still undetermined, management of this disorder continues to be directed at relief of symptomatic vocal spasm rather than cure.
History of the Procedure
Traube, who believed the condition to be a form of nervous hoarseness, first described spasmodic dysphonia (SD) in 1871. For many years, the disorder was referred to as spastic dysphonia, but the term spasmodic dysphonia is more widely accepted today.
Dedo first introduced recurrent laryngeal nerve section for the treatment of spasmodic dysphonia (SD) in 1976. Other investigators modified this approach by crushing the recurrent laryngeal nerve. However, the use of these techniques gradually declined because of a high late recurrence rate and the inherent disability that occurred.
In 1980, Isshiki et al introduced a laryngeal framework surgery (laryngoplasty) for patients with adductor spasmodic dysphonia (SD). This technique permits adjustment of the position and tension in the vocal folds. This surgical approach is still experimental, and further investigation is required.
Blitzer et al applied the botulinum toxin injection technique in 1984. This procedure has become the treatment of choice for spasmodic dysphonia (SD). Advantages of this technique include a high success rate in restoring or improving the voice. However, botulinum toxin injections provide only temporary symptomatic relief, and repeated intramuscular injections are required.
Recent surgical advances include recurrent laryngeal nerve denervation and reinnervation, as well as thyroarytenoid (TA) and lateral cricoarytenoid myectomy. These procedures have not yet been widely accepted as a primary treatment for spasmodic dysphonia (SD), and their long-term efficacy is controversial.[7, 8]
Spasmodic dysphonia (SD) is a chronic voice disorder of unknown origin that is characterized by excessive or inappropriate contraction of laryngeal muscles during speech. Spasmodic dysphonia (SD) manifests as excessive glottic closure (adductor dysphonia) or prolonged lateralization of the vocal folds (abductor dysphonia). Strained or strangled phonation and irregular voice stoppages (the form originally described and most commonly observed clinically) characterize adductor dysphonia. Abductor spasmodic dysphonia (SD) presents with a breathy or absent voice or brief vocal loss.
Early textbooks reported that spasmodic dysphonia (SD) was a relatively rare voice disorder, although recent reports suggest that it is not rare but rather frequently goes undiagnosed. Most studies show that this disorder affects females more commonly than males, with a female-to-male ratio as high as 4:1.
Reports of the mean age of patients with spasmodic dysphonia (SD) typically indicate a range of 39-45 years; however, the condition may occur as early as the second decade of life in rare exceptions and as late as the ninth decade of life.[10, 9]
Although a genetic basis of spasmodic dysphonia (SD) has not been established, some patients (12%) report relatives with similar voice problems or other dystonias.
The origin of spasmodic dysphonia (SD) is currently unknown. Primary generalized dystonia is clearly a genetic disorder and has been attributed to a defect on bands 9q32-34. The location of the genetic defect in patients with primary focal dystonias is unknown.
Spasmodic dysphonia (SD) is currently understood to be a focal dystonia that affects laryngeal muscle control during speech. Dystonia refers to a syndrome of sustained muscle contractions. Focal dystonias involve abnormal activity in only a few muscles. Dystonic movements are aggravated or become manifest during voluntary movement and worsen with fatigue or physical and emotional stress. Dystonia may be focal, segmental, multifocal, or generalized. Although spasmodic dysphonia (SD) is considered a focal dystonia, it may present as a segmental or multifocal dystonia.
Spasmodic dysphonia (SD), as with other neuromotor disorders, is frequently associated with tremor. Essential tremor causes 6- to 8-Hz shaking, primarily of the hands, head, and voice. In spasmodic dysphonia (SD), the tremor may be isolated to the larynx or may involve the pharynx, head, or even hands.
The preponderance of evidence suggests that idiopathic dystonias are due to an abnormality of neurotransmitters in the basal ganglia (putamen, head of caudate, and upper brainstem). Zweig et al suggested that the putamen and the striatopallidothalamocortical circuit are disrupted in patients with focal dystonias.
A study by Simonyan et al suggests that the pathophysiology of spasmodic dysphonia (SD) may be related to specific brain abnormalities. Evidence from both diffusion tensing imaging and neuropathological data show specific white matter changes along the corticobulbar and corticospinal tracts and in the brain regions contributing to them. Specifically, the genu of the internal capsule was found to have decreased quality and density of axonal tracts.
Postmortem histopathology also confirmed reduced axonal course and myelin content in the right genu of the internal capsule. An increase in microglial activation in these regions suggests a slow demyelination process. The changes in the CBT/CST suggest deficiency in connection between the cortical and subcortical regions, which are essential for voluntary voice production. Diffusion tensor imaging found changes in the common areas sited for focal dystonias namely the basal ganglia, cerebellum, and thalamus. Postmortem clusters of mineral accumulations in these areas may suggest a pathological process that is common to focal dystonias.
Similarly, Ali et al used H215 O PET to examine speech-related changes in regional cerebral blood flow to assess patients both before and after botulinum toxin injection. Their data demonstrate definitive patterns of cerebral activity in patients with ADSD and neurologically normal controls. Their results suggest that the pathophysiology of spasmodic dysphonia (SD) is related to sensory cortical areas as well as motor areas.
Using PET imaging, activity in the postcentral gyrus, inferior parietal lobule, and middle temporal gyrus are found to be significantly reduced in patients with ADSD. Afferent (proprioceptive/tactile) feedback mechanisms that are controlled in these sensory areas are known to play a crucial role in coordinated oral-laryngeal movements. Hypoactivity suggests that this sensory feedback is not being processed appropriately in ADSD. Without sensory feedback, intracortical inhibitory mechanisms are deficient.
Interestingly, botulinum toxin therapy resulted in a reversal of sensory hypoactivity 3-4 weeks after injection. The authors suggest that this process of renewed sensory feedback can lead to reorganization in both sensory and motor areas. Motor regions as well as the lateral premotor system (responsible for organizing and executing movements in response to afferent signals) are found to have an increase in cerebral blood flow. This suggests more efficient processing of sensory signals and possibly a return of normal inhibition. This may translate to clinical improvement in speech and voice after botulinum toxin injection.
The etiology of spasmodic dysphonia (SD) is unclear. Approximately half the patients can associate the onset if their symptoms with either an upper respiratory infection (30%) or a major life stressor (21%). A study of 350 patients with spasmodic dysphonia showed that 35% of them could identify inciting events that caused the onset of their disorder, with 45% of these noting a sudden onset of dysphonia. The most commonly cited behavioral and environmental factors surrounding the onset of this disorder were stress, upper respiratory tract infections, and pregnancy/parturition.
Adductor spasmodic dysphonia
Speech is characterized by strained or strangled phonation with intermittent voice offsets on voicing of vowels. Patients report that symptoms are worse when they are under emotional stress, when they talk on the telephone, or when they speak publically. The symptoms are often better upon awakening in the morning or after a drink of alcohol. Patients are generally able to whisper or sing without strain or vocal breaks; this is often not the case with muscle tension dysphonia and helps to clinically distinguish between the 2 disorders. Voicing is effortful, with strain and occasional hoarseness, but the essential symptom is voice breaks. The voice breaks are due to spasmodic hyperadductions of the folds that interrupt phonation. Upon fiberoptic laryngoscopy examination, the vocal folds of patients with adductor spasmodic dysphonia (SD) have intermittent rapid shortening and squeezing, which results in a quick glottic closure that shuts the glottis and interrupts airflow through the glottis.
Abductor spasmodic dysphonia
Abductor spasmodic dysphonia (SD) is rarer than the adductor type (17% of all patients with spasmodic dysphonia). Patients have prolonged voiceless consonants because of difficulties with voice onset following voiceless sounds such as /h/, /s/, /f/, /p/, /t/, and /k/. Additional symptoms in some patients with abductor spasmodic dysphonia (SD) include pitch changes, phonatory breaks during vowels, uncontrolled rises in vowels' fundamental frequency, or a breathy voice quality. Upon fiberoptic laryngoscopy, patients with abductor spasmodic dysphonia (SD) have wide-ranging abduction movements for voiceless consonants that are prolonged and interfere with following vowels.
A careful evaluation of the patient by a multidisciplinary team is needed before the best treatment for that patient can be selected. The primary treatment modality as endorsed by the American Academy of Otolaryngology- Head and Neck Surgery is currently botulinum toxin injection into the laryngeal musculature. The patient should be counseled about the advantages and disadvantages of each management approach and their expected results.
The following treatment options are currently available:
Botulinum toxin muscle injection
Type II laryngoplasty
Recurrent laryngeal nerve denervation and reinnervation
TA and lateral cricoarytenoid myectomy
Oral medical therapy
Contraindications and relative contraindications to botulinum toxin therapy are as follows:
Pregnancy: Use of botulinum toxin by women who are pregnant or lactating is not recommended.
Aminoglycosides: Recent use of aminoglycosides interferes with neuromuscular transmission and may increase the effect of the botulinum toxin therapy. The authors recommend that patients receiving aminoglycoside treatment not receive concurrent botulinum toxin injections.
Gastroesophageal reflux: Administer antireflux therapy in patients with known or suspected reflux before considering botulinum toxin injections. Botulinum toxin injections reduce the speed of vocal fold closure and may predispose the patient to aspiration.
Preexisting neurologic disorders (eg, myasthenia gravis, Eaton-Lambert syndrome, motor neuron disease affecting the neuromuscular junction): Use caution when administering botulinum toxin to patients with these disorders, especially when large doses are required. Although the amount of toxin that enters the systemic circulation after injection is minute, hyperkinetic symptoms could theoretically occur.
Traube L. Spastishe form der nervosen helserkeit. Gesammelte beltrage zur pathologie und physiologie. 1871. 2:677.
Dedo HH. Recurrent laryngeal nerve section for spastic dysphonia. Ann Otol Rhinol Laryngol. 1976 Jul-Aug. 85(4 Pt 1):451-9. [Medline].
Biller HF, Som ML, Lawson W. Laryngeal nerve crush for spastic dysphonia. Ann Otol Rhinol Laryngol. 1983 Sep-Oct. 92(5 Pt 1):469. [Medline].
Aronson AE, De Santo LW. Adductor spastic dysphonia: three years after recurrent laryngeal nerve resection. Laryngoscope. 1983 Jan. 93(1):1-8. [Medline].
Isshiki N, Haji T, Yamamoto Y, Mahieu HF. Thyroplasty for adductor spasmodic dysphonia: further experiences. Laryngoscope. 2001 Apr. 111(4 Pt 1):615-21. [Medline].
Blitzer A, Brin MF, Fahn S, Lovelace RE. Localized injections of botulinum toxin for the treatment of focal laryngeal dystonia (spastic dysphonia). Laryngoscope. 1988 Feb. 98(2):193-7. [Medline].
Chhetri DK, Mendelsohn AH, Blumin JH, Berke GS. Long-term follow-up results of selective laryngeal adductor denervation-reinnervation surgery for adductor spasmodic dysphonia. Laryngoscope. 2006 Apr. 116(4):635-42. [Medline].
Koufman JA, Rees CJ, Halum SL, Blalock D. Treatment of adductor-type spasmodic dysphonia by surgical myectomy: a preliminary report. Ann Otol Rhinol Laryngol. 2006 Feb. 115(2):97-102. [Medline].
Schweinfurth JM, Billante M, Courey MS. Risk factors and demographics in patients with spasmodic dysphonia. Laryngoscope. 2002 Feb. 112(2):220-3. [Medline].
Blitzer A, Brin MF, Stewart CF. Botulinum toxin management of spasmodic dysphonia (laryngeal dystonia): a 12-year experience in more than 900 patients. Laryngoscope. 1998 Oct. 108(10):1435-41. [Medline].
Kramer PL, de Leon D, Ozelius L, et al. Dystonia gene in Ashkenazi Jewish population is located on chromosome 9q32-34. Ann Neurol. 1990 Feb. 27(2):114-20. [Medline].
Zweig RM, Hedreen JC, Jankel WR, Casanova MF, Whitehouse PJ, Price DL. Pathology in brainstem regions of individuals with primary dystonia. Neurology. 1988 May. 38(5):702-6. [Medline].
Simonyan K, Tovar-Moll F, Ostuni J, et al. Focal white matter changes in spasmodic dysphonia: a combined diffusion tensor imaging and neuropathological study. Brain. 2008 Feb. 131:447-59. [Medline].
Ali SO, Thomassen M, Schulz GM, et al. Alterations in CNS activity induced by botulinum toxin treatment in spasmodic dysphonia: an H215O PET study. J Speech Lang Hear Res. 2006 Oct. 49(5):1127-46. [Medline].
Childs L, Rickert S, Murry T, Blitzer A, Sulica L. Patient perceptions of factors leading to spasmodic dysphonia: A combined clinical experience of 350 patients. Laryngoscope. 2011 Jul 20. [Medline].
Creighton FX, Hapner E, Klein A, et al. Diagnostic Delays in Spasmodic Dysphonia: A Call for Clinician Education. J Voice. 2015 Apr 11. [Medline].
Hillel AD. The study of laryngeal muscle activity in normal human subjects and in patients with laryngeal dystonia using multiple fine-wire electromyography. Laryngoscope. 2001 Apr. 111(4 Pt 2 Suppl 97):1-47. [Medline].
Fulmer S, Merati A, Blumin J. Efficacy of laryngeal botulinum toxin injection: Comparison of two techniques. Laryngoscope. 2011 Sep. 121(9):1924-8.
Sanuki T, Isshiki N. Overall evaluation of effectiveness of type II thyroplasty for adductor spasmodic dysphonia. Laryngoscope. 2007 Dec. 117(12):2255-9. [Medline].
Murry T, Woodson GE. Combined-modality treatment of adductor spasmodic dysphonia with botulinum toxin and voice therapy. J Voice. 1995 Dec. 9(4):460-5. [Medline].
Hallett M. How does botulinum toxin work?. Ann Neurol. 2000 Jul. 48(1):7-8. [Medline].
Thomas JP, Siupsinskiene N. Frozen versus fresh reconstituted botox for laryngeal dystonia. Otolaryngol Head Neck Surg. 2006 Aug. 135(2):204-8. [Medline].
Bielamowicz S, Squire S, Bidus K, Ludlow CL. Assessment of posterior cricoarytenoid botulinum toxin injections in patients with abductor spasmodic dysphonia. Ann Otol Rhinol Laryngol. 2001 May. 110(5 Pt 1):406-12. [Medline].
Stong BC, DelGaudio JM, Hapner ER, Johns MM 3rd. Safety of simultaneous bilateral botulinum toxin injections for abductor spasmodic dysphonia. Arch Otolaryngol Head Neck Surg. 2005 Sep. 131(9):793-5. [Medline].
Holden PK, Vokes DE, Taylor MB, Till JA, Crumley RL. Long-term botulinum toxin dose consistency for treatment of adductor spasmodic dysphonia. Ann Otol Rhinol Laryngol. 2007 Dec. 116(12):891-6. [Medline].
Hillel AD, Maronian NC, Waugh PF, Robinson L, Klotz DA. Treatment of the interarytenoid muscle with botulinum toxin for laryngeal dystonia. Ann Otol Rhinol Laryngol. 2004 May. 113(5):341-8. [Medline].
Ludlow CL, Naunton RF, Terada S, Anderson BJ. Successful treatment of selected cases of abductor spasmodic dysphonia using botulinum toxin injection. Otolaryngol Head Neck Surg. 1991 Jun. 104(6):849-55. [Medline].
Chan SW, Baxter M, Oates J, Yorston A. Long-term results of type II thyroplasty for adductor spasmodic dysphonia. Laryngoscope. 2004 Sep. 114(9):1604-8. [Medline].
Nomoto M, Tokashiki R, Hiramatsu H, et al. The Comparison of Thyroarytenoid Muscle Myectomy and Type II Thyroplasty for Spasmodic Dysphonia. J Voice. 2015 Feb 27. [Medline].
Berke GS, Blackwell KE, Gerratt BR, Verneil A, Jackson KS, Sercarz JA. Selective laryngeal adductor denervation-reinnervation: a new surgical treatment for adductor spasmodic dysphonia. Ann Otol Rhinol Laryngol. 1999 Mar. 108(3):227-31. [Medline].
Allegretto M, Morrison M, Rammage L, Lau DP. Selective denervation: reinnervation for the control of adductor spasmodic dysphonia. J Otolaryngol. 2003 Jun. 32(3):185-9. [Medline].
Blitzer A, Brin MF, Stewart C, Aviv JE, Fahn S. Abductor laryngeal dystonia: a series treated with botulinum toxin. Laryngoscope. 1992 Feb. 102(2):163-7. [Medline].
Ozelius LJ, Hewett JW, Page CE, et al. The early-onset torsion dystonia gene (DYT1) encodes an ATP-binding protein. Nat Genet. 1997 Sep. 17(1):40-8. [Medline].
Sulica L. Contemporary management of spasmodic dysphonia. Curr Opin Otolaryngol Head Neck Surg. 2004 Dec. 12(6):543-8. [Medline].