Spasmodic Dysphonia Evaluation and Management

1. Spasmodic DysphoniaEvaluation and Management UTMB Department of Otolaryngology OlviaRevelo, MSIV Faculty Advisor:MichaelUnderbrink, MD Grand Rounds Presentation March 10, 2009

2. Overview • Introduction • Anatomy of the larynx • Etiology • Diagnosis • Clinical features • Therapy • Pharmacologic • Surgical • Conclusion

3. Introduction • Spasmodic dysphonia (SD) • Focal, adult-onset dystonia of laryngeal muscles • Intermittent phonatory breaks during speech secondary to spasms • Usually task specific - symptomatic when attempting voluntary speech • May be asymptomatic during reflexive phonation (coughing, laughing, crying, yawning) • Symptoms reduced/absent during singing or whisper

4. Associations • May be associated with: • Other focal dystonias • Blepharospasms, Torticollis, Writer’s Cramp • Underlying neurological • Parkinson’s, ALS • Environmental • Infection, trauma, meds • Psychogenic stimulus • Stress

5. Demographics • Affects approximately 1:10,000 Americans • Female to male ratio 3:1 up to 8:1 • Peak age of onset 35-45 • Positive family history in 12% of affected pt’s

6. Types of Laryngeal Dystonias • Adductor – irregular hyperadduction of vocal folds with excessive glottic closure • Abductor – incomplete, irregular vocal fold approximation • Mixed – both elements are present

7. Anatomy: Laryngeal Cartilage Netter

8. Anatomy: Laryngeal Cartilage Netter

9. Anatomy: Laryngeal Muscles Netter

10. Anatomy: Laryngeal Muscles Netter

11. Anatomy: Laryngeal Motion • Abduction of vocal ligament Netter

12. Anatomy: Laryngeal Motion • Adduction of vocal ligament Netter

13. Anatomy: Laryngeal Motion • Tension of vocal ligament Netter

15. Anatomy: Laryngeal Innervation Netter

16. Etiology • Currently unknown • Historically psychogenic disorder • Traube 1871 “nervous hoarseness” • Current theory involves neurologic cause • Basal ganglia involved in other focal dystonias • Some patients have developed SD post head trauma

17. Diagnosis Diagnosis is based on history and examination of the glottis during various laryngeal tasks. Aronson defined “idiopathic spastic dysphonia”: The voice signs of SD Absence of VC lesions/paralysis Normal peripheral speech mechanisms Resistance of symptoms to voice therapy and psychotherapy

18. Clinical Features: Adductor Type • Most common ~85% of diagnosed cases • Choked, strained-strangled voice, with abrupt breaks in phonation in the middle of vowels • Breaks are due to hyper-adduction of the folds • Difficulty with “We eat eels every day” and “We mow our lawn all year”

19. Clinical features: Abductor Type • Rare ~15% of patients with SD • Breathy, effortful voice with abrupt breaks resulting in whispered elements of their speech. • Excessive and prolonged abduction during voiceless consonants (/h/,/s/,/f/,/p/,/t/,/k/) • Difficulty with “The puppy bit the tape” and “When he comes home we’ll feed him”

20. Mixed Type • Extremely rare, with symptoms of both adductor and abductor type • Diagnosis important for predicting treatment response

21. Diagnosis • Electromyography • Fiberopticlaryngoscopy • Videostroboscopy • Aerodynamic testing • Vocal spectrographic analysis

22. Therapy • Pharmacotherapy • Botox • Neuropharmacologic • Voice Therapy • Surgical • Recurrent laryngeal nerve section • Recurrent laryngeal nerve avulsion

23. Therapy • Surgical - Experimental • Recurrent laryngeal nerve denervation and reinnervation • Type II thyroplasty • Posterior cricoarytenoidmyoplasty with medializationthyroplasty

24. Botulinum Toxin • Goldstandard treatment for SD • Prevents presynaptic release of acetylcholine (Ach) at neuromuscular junction. • Different serotypes of botulinum toxin exhibit specific proteolysis of proteins involved in transport and binding of Ach vesicles to presynaptic membrane. • Result in temporary paralysis

25. Botox mechanism of action Release of acetylcholine at the neuromuscular junction is mediated by the assembly of a synaptic fusion complex that allows the membrane of the synaptic vesicle containing acetylcholine to fuse with the neuronal cell membrane. The synaptic fusion complex is a set of SNARE proteins, which include synaptobrevin, SNAP-25, and syntaxin. After membrane fusion, acetylcholine is released into the synaptic cleft and then bound by receptors on the muscle cell. JAMA. 2001;285:1059-1070

26. Botox mechanism of action Botulinum toxin binds to the neuronal cell membrane at the nerve terminus and enters the neuron by endocytosis. The light chain of botulinum toxin cleaves specific sites on the SNARE proteins, preventing complete assembly of the synaptic fusion complex and thereby blocking acetylcholine release. Botulinum toxins types B, D, F, and G cleave synaptobrevin; types A, C, and E cleave SNAP-25; and type C cleaves syntaxin. Without acetylcholine release, the muscle is unable to contract.

27. Botulinum Toxin • Effects and Side Effects: • Reduction in voice breaks reported by 48 hrs • Treatment lasts an average of 3-4 months before recurrence of symptoms • Most common side effect is breathiness • Other side effects include: dysphagia, prologued voice loss, aspiration, hoarseness, pain at injection site and stridor (with PCA injection)

28. Botulinum Toxin No absolute contraindications Used safely in children Give antireflux medication to patients with reflux 3 – 5% of patients have developed resistance to the toxin Resistant patients can sometimes be treated with other toxin serotypes

29. Botulinum Toxin • Injection technique for adductor SD (AdSD) • Percutaneous injection guided by electromyographic (EMG) signals. • Needle inserted through thyrocricoid membrane and directed upward toward contralateral thyroarytenoid m. • Phonation and observation of interference pattern on EMG verifies position

30. Thyroarytenoid injection for adductor spasmodic dysphonia. Needle is advanced through the cricothyroid membrane. Pitman MJ http://www.emedicine.com/ent/TOPIC349.HTM

31. Botulinum Toxin • Alternate injection techniques for AdSDAll methods yield comparable results. Very patient and physician dependent. • Transoral laryngoscopic injections • The transoral approach involved indirect visualization of the VF via standard laryngoscopicprecedure. VF anesthetized through application of topical cocaine sol’n. BTX is then injected along the superior margin of the VF • Transnasal laryngoscopic injections • Transnasal technique uses a flexible nasolaryngoscope with a working channel that is equipped with a flexible catheter needle. Topical phenylephrine and lidocaine are sprayed transnasally, then the scope is introduced. Once in place, lidocainesol’n drip is applied to the surface of the VF via the working channel while the pt phonates to prevent airway penetration or aspiration. Then inject just lateral to the true VF (to avoid damage to VF mucosa) • Transcartilaginous “point touch” injections • Insertion of the needle through the surface of the thyroid cartilage halfway b/w thyroid notch and inferior edge. Following insertion the needle is passed through the cartilage and into TA muscle where BTX is injected

32. Botulinum Toxin • Injection technique for abductor SD (AbSD) • Requires access to posterior cricoarytenoids • Larynx is rotated manually away from injection site. Needle passed posterior to the posterior edge of thyroid at cricoid level into the PCA. • Patient is asked to sniff to contract PCA and verify correct position

33. Posterior cricoarytenoid (PCA) injection for abductor spasmodic dysphonia. Needle is advanced through the inferior constrictor muscle to the PCA muscle. Pitman MJ http://www.emedicine.com/ent/TOPIC349.HTM

34. Botulinum Toxin • Blitzer et al. 1999 • Reported their 12 yr experience with more than 900 patients with SD • 90% of patients with AdSD and 66.7% with AbSD achieved a normal voice after injection • Injection after nerve section failure showed up to 81% improvement • Patients with combined abnormalities only had 30% improvement -Level of evidence (LOE): A

35. Botulinum Toxin • Advantages • Less invasive than surgery • No permanent damage to nerve or laryngeal structures • Temporary nature allows for dosage adjustments • Readily available • Disadvantages • Need for repeated injections • Unpredictable relationship between dosage and response • Resistance to treatment • Adverse side effects

36. Pre-Botox Treatment

37. Post-Botox Treatment

38. Pre-Botox Treatment

39. Post-Botox Treatment

40. Neuropharmacology No controlled studies demonstrate effective symptom control Beta blockers – propranolol Anticholinergics – trihexyphenidylHCl (Artane) Benzodiazepines – diazepam, alprazolam Role has been to provide relief without any demonstrable symptom reduction

41. Voice Therapy • No demonstrated effectiveness in treating SD • May help: • Rule out psychogenic disorder • Provide support for those who do not benefit from Botox (mild symptoms) • Some patients use it in adjunct to Botox to prolong symptom free period • Traditional voice therapy approaches for ADSD employ techniques for avoiding overpressure. Breathy voice onsets, reduced speech force, using a head focus, and laryngeal manipulation are aimed at reducing laryngeal tension. Can also use relaxation and respiration training to help gain insight and control of laryngeal tension during speech.

42. Recurrent laryngeal nerve section • Dedo 1976 • Case series of 34 patients that had RLN section • “All experienced symptom improvement” • No objective measurement of outcome -LOE:C • Dedo 1991 • Retrospective review of 300 patients after RLN section • 82% had little or no symptoms after 5-14 years • No prospective comparative data available -LOE:B

43. Recurrent laryngeal nerve section • Aronson and DeSanto 1983 • Followed 33 patients for 3 years post RLN section • 36% maintained improved voices • Of the 64% failed voices, 48% were worse than before surgery • Effectiveness of unilateral RLN section for severe ADSD decreases with time • Limitations: small sample study -LOE:C

44. Recurrent laryngeal nerve avulsion • Netterville 1991 • Retrospective review of 12 patients • No recurrence at 1.5 years -LOE:C • Follow up report 1996 • 18 patients followed for 3-7 yrs post RLN avulsion • 16/18 patients were without spasm • Most common side effect was breathy voice – Six underwent medializationlaryngoplasty -LOE:C

45. Therapy • Surgical Experimental • Recurrent laryngeal nerve denervation and reinnervation • Type II thyroplasty • Posterior cricoarytenoidmyoplasty with medializationthyroplasty

46. Recurrent laryngeal nerve denervation and reinnervation • Berke and Blumin 2006 • Retrospective study analyzing satisfaction surveys and perceptual evaluation of post operative voice • 83 of 136 patients returned surveys with 91% satisfied with fluency of voice • 46 patients provided voice recordings for perceptual evaluation: 26% had voice breaks, and 30% breathiness -LOE:B

47. Recurrent laryngeal nerve denervation and reinnervation Limitations: high drop out rate (61%), small sample size, no long term prospective studies Disadvantages Technical difficulty Recurrence of symptoms Does not prevent unwanted reinnervations • Advantages • Permanent effect • Less breathiness due to maintenance of VF tone from ansacervicalisinnervation

48. Midline lateralization thyroplasty • Isshiki et al. 2001 • Retrospective review of 6 SD patients • 5/6 patients obtained near normal voices • Failure attributed to difficulty in lateralization and concurrent focal neck dystonia • Limitations: small samples, no long term prospective studies, no objective measures described -LOE:C

49. Atlas of Head & Neck Surgery—otolaryngology By Byron J. Bailey, Karen H. Calhoun, Norman

50. Modified Type II Thyroplasty Midline lateralization thyroplasty (type 2 thyroplasty) after completion of the procedure. “A” type using a composite graft for the closure of a tiny perforation at or slightly above the anterior commissure. A muscle flap is used to cover the graft. G = A composite graft. Isshiki: Laryngoscope, Volume 111(4).April 2001.615-621