VOCAL CORD PALSY PRESENTATION ENT TEAM

PRESENTATION BY ENT TEAM

1. Vocal cord palsy Nur Izzaty Nadia Mohd Ariffin

2. INTRODUCTION Vocal cord palsy: partial interruption of nerve impluse resulting in weak or abnormal movement of laryngeal muscles Vocal cord paralysis: total interruption of nerve impulse resulting in no movement of laryngeal muscles It is a sign of a disease with multiple etiologies and not a diagnosis by itself Can occur at any age or sex

3. ANATOMY OF LARYNX Functions of larynx Swallowing Coughing Effort closure Biomechanics for phonation

4. Laryngeal cartilages Paired Arytenoid Cuneiform Corniculate Unpaired Thyroid Cricoid Epiglottis

5. Laryngeal muscles

6. Laryngeal muscles INTRINSIC MUSCLES: Ab duct (open) or ad duct (close) the folds. Vocal fold length and tension. Attach at origin and insertion of different cartilages Roles in respiration, swallowing, and vocalization.

7. Adduction of vocal cords

8. Adduction of vocal cords

9. Abduction of vocal cords

10. Extrinsic laryngeal muscle Muscles with a single attachment to the laryngeal cartilage Divided into 2 groups: Cervical muscles Suprahyoid muscles; act as elevator of the larynx Infrahyoid muscles; act as depressors of the larynx Pharyngeal muscles, including the inferior constrictor muscles

11. Table 58.1

12. Nonkeratinizing, stratified squamous epithelium connective tissue superficial layer (Reinke’s space) tissue loosely connected to the other layers intermediate layer elastic fibers (stretchy) deep layer collagen fibers (not stretchy) muscle (TA) Basic structure of the vocal cord Lamina propria Vocal ligamen t

13. Nerve supply

14. Superior laryngeal nerve (SLN) It arises from inferior ganglion of the Vagus nerve , descends behind internal carotid artery and at the level of greater horn of hyoid bone , divides into external and internal branches The external branch supplies cricothyroid muscle while the internal branch pierces the thyrohyoid membrane and supplies sensory innervation to the larynx and hypopharynx

15. Superior laryngeal nerve (SLN) Internal branch consist of both sensory and parasympathetic secreto -motors fibre , which supply glands within tissue above the level of vocal cord. Divided into 3 branches: the superior branch runs to the lingual surface of the epiglottis and sends small fibres through the epiglottic foramina to the laryngeal surface; the middle branch runs through the aryepiglottic fold into the ventricular fold; the inferior branch runs to the pyriform sinus and to the post cricoid region, forming various anastomoses with the RLN.

16. Joll’s triangle Used to identify the location of external branch of superior laryngeal nerve during thyroid surgeries. Boundaries: Lateral - Upper pole of thyroid gland and superior thyroid vessels Superior - Attachment of the strap muscles and deep investing layer of fascia to the hyoid Medial - Midline Floor - Cricothyroid muscle

17. Recurrent laryngeal nerve (RLN) Right RLN arises from the vagus nerve at the level of subclavian artery , hooks around it and ascends in tracheoesophageal grooves. Left RLN arises from the vagus nerve in the mediastinum at the level of arch of aorta , loops around it and ascends into the neck in the tracheo-oesophageal grooves Left RLN has much longer course which makes it prone to paralysis compared to the right one.

18. Beahr’s triangle The RLN is at high risk of injury during thyroid surgeries. RLN is commonly sought in the tracheo oesophageal groove in between the branches of inferior thyroid artery.  The inferior thyroid artery is a branch of thyrocervical trunk on the right side.   It enters the neck by piercing the prevertebral fascia medial to the carotid sheath to enter the posterior part of thyroid gland.   During it makes sense to identify the recurrent laryngeal nerve before dividing the branches of inferior thyroid artery. Superiorly – inferior thyroid artery Laterally – common carotid artery Medially – RLN

19. Theories on position of vocal cord in vocal cord paralysis Semon’s Law This law explain median or paramedian position of the vocal cord In all progressive organic lesions, abductor fibres of RLN, which are phylogenetically newer, are more susceptible and thus first to be paralyzed compared to adductor fibres Nerve fibres supplying abductors are in periphery of RLN Muscle bulk for the abductors is less, more susceptible Phylogenetically , larynx main function is protection, so adductor function are maintained

20. Semon’s law Stages 1 st stage: only abductor fibres damaged, vocal cord approximate in midline, adduction still possible ( paramedian position) 2 nd stage: contracture of the adductor, vocal folds immobilized in median posiition 3 rd stage: adductor become paralyzed, vocal cord assumes cadaveric position

21. Wegner and Grossman theory Most widely accepted theory In the absence of cricoarytenoid joint fixation, an immobile vocal cord in paramedian position has total pure unilateral recurrent nerve paralysis, and immobile vocal cord in lateral position has a combined paralysis of superior and recuurent nerves (the adductive action of cricothyroid muscle is lost)

22. Modern theory Final position of paralysed vocal cord is not static and determined by: Degree of paralysed muscle atrophy Degree of reinnervation following injury Extent of synkinesis (mass movement) of all intrinsic muscle Fibrosis of denervated muscle Contour of vocal cord Length of vocal cord Mass of vocal cord

23. Vocal cord positions

24. Etiology of vocal cord palsy Unilateral vocal cord palsy Malignancy 25% Iatrogenic surgical trauma 25% Idiopathic 20% Non-surgical trauma 11% Intubation 7% Neurological disorder 7% Bilateral vocal cord palsy Iatrogenic 44% Malignancy 17% Neurological 12% Intubation 15% Idiopathic 12%

25. Etiology of vocal cord palsy Cervical surgery Thyroidectomy/parathyroidectomy Carotid endartectomy Anterior approach to cervical spine Repair of Zenker’s diverticulum Cricopharyngeal myotomy Thoracic procedure Thoracic aneurysm repair Pneumonectomy Aortic valve repair Coronary artery bypass grafting Esophageal/ trachela surgery Mediastinoscopy Ligation of PDA

26. Etiology of vocal cord palsy Others Skull base/brainstem surgery ETT intubation

27. CLASSIFICATION OF VOCAL CORD PALSY Can be classified into Unilateral or Bilateral May involve Superior laryngeal nerve Recurrent laryngeal nerve Both (combine)

28. Nerve Unilateral SLN Unilateral RLN Bilateral RLN Symptoms Frequent throat clearing, paroxysmal coughing, voice fatigue, vague foreign body sensations, slight voice change Diplophonia (with decreased range of pitch, most noticeable when trying to sing Breathy and fatigue voice, able to compensate Good voice Variable degree of stridor Vocal cord Normal VC position during respiration At rest, vc on paralyzed side is slightly shortened and bowed VC at paramedian position (loss of abduction with intact adduction by cricothyroid) Airway is adequate and may become compromised with exertion VC in paramedian position

29. Clinical presentation Voice changes Dysphonia or hoarseness Vocal fatigue Aphonia Respiratory symptoms Shortness of breath Stridor (biphasic) Weak/ineffective cough Swallowing difficulties Dysphagia Aspiration

30. Evaluation - History Symptoms Voice changes Aspiration Weak, ineffective cough Explore history to find the cause Past medical and surgical history Social history

31. Physical examination General appearance Stridor, variable degree Dyspnea Respiratory distress Complete head and neck examination Cranial nerve examination Quality of voice Maximum phonation time Cough effort Nasopharyngolaryngoscopy : Assess position of vocal cord Glottic gap, airway patency and adequacy Pooling or aspiration

32. Investigation CXR – to screen for intrathoracic lesion CT base of skull until thorax - to evaluate the course of RLN from base of skull to thorax MRI brain – screen for CNS disorder EUA: direct laryngoscopy

33. Laryngeal electromyography (LEMG) Assess the integrity of laryngeal nerves Needle electrode placement into thyroarytenoid and cricoarythenoid muscle It assess muscle at rest and voluntary motor unit recruitment May not be useful in diagnosis

34. Normal Joint Fixation Post. Scar Fibrillation Denervation Polyphasic Synkinesis Reinnervation

35. Videostroboscopy Assess the structure and movement of the vocal cords Gives additional information about vibratory pattern of the vocal fold mucosa and improves accuracy of diagnosis

36. Differential diagnosis in unilateral vocal cord palsy Cricoarytenoid fixation Caused by joint subluxation/dislocation with ankylosis Joint fixation by rheumatoid arthritis or gout Normal LEMG Laryngeal malignancy

37. Vocal cord palsy vs CA joint fixation Vocal cord paralysis Floppy, bowing Arytenoids falls anteromeidally , movable passively VC at higher level Tilting of larynx to the palsy side Flickering of cord on phonation Shallow pyriform fossa Fixed in specific position Cricoarytenoid joint fixation Normal VC Arytenoid in position but fixed VC at same level No tilting No flickering Any position

38. To be continued

39. MANAGEMENT Treatment goal: To improve voice and prevent aspiration Patient factors affect treatment strategies Presence of aspiration Nature of nerve injury Vocal demands Medical comorbidities LEMG findings

40. Treatment Non surgical Voice therapy Therapeutic goals: to produce optimal functionality within daily and specialized voice applications Includes optimizing and rebalancing components of phonation (respiration, phonation, resonance) Observation for 6-12months Speech therapy Provides voice therapy Teaches vocal hygiene and compensatory strategies Identifies and eliminates counterproductive compensatory strategies Pre operative and post operative assessment

41. Treatment Surgical intervention: Temporary: Injection laryngoplasty Permanent: Injection laryngoplasty Thyroplasty Arytenoid adduction Laryngeal reinnervation

42. Vocal cord medialization technique Injection laryngoplasty Type 1 Thyroplasty ( Isshiki’s ) Arytenoid adduction Reinnervation procedures

43. Injection laryngoplasty Indications: Temporary correction in cases of unilateral vocal cord palsy - prognosis for recovery is uncertain. Immediate improvement of voice required Permanent correction of glottic insufficiency Vocal fold atrophy Adjunctive augmentation prior surgery Trial basis Note: Done when there is absence of arytenoid fixation and there is adequate residual vocal fold structure to allow for needle placement.

44. Ideal injection material Readily available Inexpensive Inert Easy to use Completely biocompatible Injectable materials are broadly classified into temporary and permanent types.

45. Injection material TEFLON It is polymer of tetrafluoroethylene, permanent effect Consist of 50% glycerine that will be absorbed in first few weeks Disadvantages: Later causing localized granuloma, irreversible. FAT Easily harvested, readily available, does not give foreign body reaction Immediate effect, 30%-50% will be absorb in first month Decreased volume with time Morbidity

46. Injection material GLYCERINE Temporary effects, absorbed within 2-6 weeks Reversible and frequently combined with LEMG COLLAGEN Easily harvested, readily available, does not give foreign body reaction Immediate effect, 30%-50% will be absorb in first month Decreased volume with time Morbidity

47. Temporary injectable substances

48. Permanent injectable substances

49. Vocal cord injection technique It may be done under: GA: direct laryngoscopy

50. Vocal cord injection technique LA (indirect laryngoscopy): Transcutaneous route through cricothyroid membrane Transcutaneous through thyroid cartilage Transcutaneous through thyrohyoid membrane Transoral route

51. Complications of vocal cord injection Requiring repeated procedures Over injection causing airway compromise Improper placement causing subglottal extension and stenosis Causing granuloma if given to Reinke’s space

52. Adapted from Scott Brown’s otorhinolaryngology Head and Neck Surgery, Volume 3, 8th edition

53. Type 1 Thyroplasty (medialization thyroplasty ) Popularized by Isshiki et al Performed in patient with unilateral vocal cord palsy, can also be performed in bilateral VCP in cases of bilateral bowed VC Done under LA To allow phonation and optimal positioning of the implant Indications: Unilateral vocal cord palsy Vocal cord atrophy Sulcus vocalis Contraindications: Malignant disease h/o radiotheraphy to larynx

54. Technique Preoperative IV steroid ± antibiotics (surgeon preference, weak evidence) Thyroid cartilage exposed and outer perichondrium elevated and retracted Thyrotomy window marked with 3-mm inferior strut (to prevent breakage of cartilage), with anterior border approximately 7 mm (females) or 9 mm (males) from midline J Ross, H Panossian , M J Hawkshaw, R T Sataloff . Laryngology: Clinical Reference Guide Plural Publishing, 2019

55. The size of the window is dependent on the size of the larynx, men > women Anterior border should be about 5-7mm posterior to midline in female and 8-10mm in male. Posterior border should be just anterior to the oblique line (width usually about 10-13mm) Inferior border should be about 2-3 mm superior to the inferior border to prevent fracturing (height usually 4- 6mm)

56. Technique

57. Implant: Preformed: Montgometry Titanium Hand carved: Silicone Layered Gore-Tex

58. Type 1 thyroplasty Advantages: Under local anesthesia. - positioning is more anatomic, better assessment of voice Reversible Prosthesis is placed lateral to the inner perichondrium of the thyroid lamina. Structural integrity of the vocal fold is preserved, allowing medialization with effective closure of the prephonatory gap

59. Complications: I ntraoperative or postoperative extrusion of implant Shifted implant with inadequate or excessive medialization Excessive anterior or inferior placement leading to strained phonation Hemorrhage with hematoma along vibratory margin and subsequent stiffness Infection (rare) Airway obstruction (rare)

60. Arytenoid adduction Indicated to correct posterior glottic gap; common in high vagal injury Arytenoid adduction recreates tension in direction of LCA muscle— often performed in conjunction with type I thyroplasty under local anesthesia

61. Laryngeal reinnervation Focus on maintaining muscle tone and prevent atrophy and fibrosis Indication: Poor chance of spontaneous recovery Two most common reinnervation technique: Neuromuscular pedicle Ansa cervicalis - RLN anastomosis May be combined with injection laryngoplasty until reinnervation

62. Treatment – Bilateral vocal cord palsy Tracheostomy – if airway compromise The principal procedures for treatment of BLVCP are vocal cord lateralization and removal of vocal cord or arytenoid tissue

63. Vocal cord lateralization aims to surgically widen the glottic opening by excising a wedge of thyroarytenoid muscle. Arytenoidectomy is currently the gold standard for the management of BLVCP and involves the removal of some or all of the arytenoid cartilage. Concerns with regards to aspiration observed with complete removal of the arytenoid have led to more conservative removal. Partial cordectomy is the procedure of choice and involves laser excision of part of the vocal process and a C-shaped wedge from the posterior area of one vocal cord

64. Conclusion Vocal cord palsy is a manifestation of disease and not a diagnosis. The approach to ULVCP is usually conservative, with voice quality and the exclusion of malignant pathology the foremost concern In cases of BLVCP the airway will be the preeminent issue The timing of surgical intervention, if any, will ultimately depend on patient circumstances, recovery potential and the severity of symptoms.

65. References Watkinson, John C., Clarke, Ray. Scott-Brown’s otorhinolaryngology, head and neck surgery . 8 th edition. 2018. Timon, C., Cashman, E.. Vocal cord paralysis. Logan Turner’s Disease’s of the throat, nose and ear; head and neck surgery . 2016. pg 301. Ross, J., Panossian , H., Hawkshaw, M.J., Sataloff , R. T., Laryngology: Clinical Reference Guide. Plural Publishing, 2019.