1. Vocal cord palsy & evaluation of hoarseness
Dr. Vishal Sharma

3. Nerve supply of larynx Motor supply of intrinsic muscles:
Cricothyroid muscle: superior laryngeal nerve
All other muscles: recurrent laryngeal nerve
Sensory:
Above vocal cord: superior laryngeal nerve
Below vocal cord: recurrent laryngeal nerve

4. Recurrent laryngeal nerve
Right:
Arises from vagus at level of right subclavian artery & hooks around it
Left:
Arises from vagus in mediastinum at level of arch of aorta & loops around it

5. Development of arterial arches

6. Final position of B/L RLN

7. Superior laryngeal nerve
Arises from inferior ganglion of vagus
Descends behind internal carotid artery at level of greater cornu of hyoid bone divides into external & internal branches
External motor branch: to cricothyroid muscle
Internal sensory branch: pierces thyrohyoid membrane to enter larynx

9. Dual innervation of inter-arytenoid muscles

10. Classification
A. Incomplete paralysis 1. Recurrent laryngeal nerve palsy a. Left (75% ), Right (15%), B/L (10%) b. Abductor, Adductor 2. Superior laryngeal nerve palsy B. Combined paralysis / complete paralysis

11. Causes of laryngeal paralysis
Supra-nuclear
Nuclear: nucleus ambiguus
High vagal lesions: combined palsy
Low vagal lesions: recurrent laryngeal nerve palsy
Systemic causes
Idiopathic

12. Causes of combined paralysis
Intracranial Neck Tumors of posterior fossa Penetrating injury Basal meningitis (TB) Parapharyngeal tumors Skull base Metastatic neck nodes Fractures Lymphoma Nasopharyngeal cancer Thyroid surgery Glomus tumour

13. Etiology of recurrent laryngeal nerve palsy

14. Malignancy (25%): lung (>50%), thyroid, esophageal,
Malignancy (25%): lung (>50%), thyroid, esophageal, nasopharyngeal, metastatic neck node
Surgical trauma (20%): during surgeries of lung, heart, thyroid, esophagus, mediastinum
Inflammatory (13%): tuberculosis, syphilis
Idiopathic (13%): viral neuritis
Non-surgical trauma (11%): accidental neck trauma,
left atrial enlargement (Ortner), aortic aneurysm
Neurological (7%): CVA, head injury, Parkinsonism, multiple sclerosis, alcoholic / diabetic neuropathy
Others (11%): rheumatoid arthritis, haemolytic anemia

15. Causes of left RLN palsy (75%)
Neck
 Accidental trauma
 Thyroid disease
 Thyroid surgery
 Ca esophagus
 Lymphadenopathy
Mediastinum
 Bronchogenic ca
 Ca esophagus
 Aortic aneurysm
 Lymphadenopathy
 Enlarged left atrium
 Intra-thoracic surgery

16. Causes of right RLN palsy (15%)
Neck trauma
Thyroid disease
Thyroid surgery
Ca cervical esophagus
Cervical lymphadenopathy
Aneurysm of subclavian artery
Ca apex right lung
TB of cervical pleura

17. Causes of B/L RLN palsy (10%)
Thyroid surgery
Ca thyroid
Cancer cervical esophagus
Cervical lymphadenopathy

18. Congenital vocal cord paralysis
Unilateral: birth trauma, congenital anomaly of great vessel or heart
Bilateral:
 Hydrocephalus  Meningocoele
 Arnold-Chiari malformation  Cerebral agenesis
 Intra-cerebral hemorrhage  Nucleus ambiguus agenesis

19. Thyroid surgery Joll’s sterno-thyro-laryngeal triangle for S.L.N.:
Lateral = superior thyroid vessels & upper thyroid pole; superior = attachment of strap muscles to thyroid cartilage; medially = midline
Beahr’s triangle for recurrent laryngeal nerve:
Lateral = common carotid artery; superior = inferior thyroid artery; medial = tracheo-esophageal groove + recurrent laryngeal nerve

20. Joll’s triangle for SLN

21. Beahr’s triangle for RLN

22. Why right RLN commonly damaged in thyroid surgery?
Right recurrent laryngeal nerve more superficial
Right nerves enters thyroid at 450 angle but left lies in tracheo-esophageal groove
Right nerve mostly passes superior to or b/w branches of inferior thyroid artery; left nerve mostly passes deep to inferior thyroid artery

23. Paralysis of both RLN & SLN Paralysis of adductors
Position of vocal cord
Distance from centre
Healthy
Diseased
Median
Midline
Phonation
RLN paralysis
Paramedian
1.5 mm
Strong whisper
Intermediate
(Cadaveric)
3.5 mm
(neutral position)
Paralysis of both RLN & SLN
Gentle abduction
7 mm
Quiet respiration
Paralysis of adductors
Full abduction
9.5 mm
Deep inspiration --

24. Position of vocal cords

25. Semon’s Law Rosenbach (1880) & Semon (1881)
“In all progressive organic lesions, abductor fibres of recurrent laryngeal nerve, which are phylogenetically newer, are more susceptible and thus first to be paralyzed compared to adductor fibres.”

26. 1st stage: only abductor fibres damaged; vocal folds approximate in midline; adduction still possible (paramedian position) 2nd stage: contracture of adductors; vocal folds immobilized in median position 3rd stage: adductors become paralyzed; vocal fold assumes cadaveric position

27. Why abductors affected first ?
Nerve fibres supplying abductors are in periphery of recurrent laryngeal nerve
Muscle bulk for the abductors is less, more susceptible
Phylogenetically, larynx’s main function is protection, so adductor functions are maintained

28. Wagner & Grossman Theory
In isolated paralysis of recurrent laryngeal nerve, cricothyroid muscle (which receives innervation from superior laryngeal nerve) keeps vocal cord in paramedian position due to adductor function
In superior laryngeal nerve palsy, cord lies in intermediate (cadaveric) position

29. Modern theory
Final position of paralyses vocal cord is not static & is decided by:
Degree of paralyzed muscle atrophy & fibrosis
Degree of re-innervation following injury
Extent of synkinesis (mass movement) of all intrinsic muscles
Fibrosis & ankylosis of crico-arytenoid joint

30. Intermediate position of vocal cords in RLN palsy ?
Retrograde atrophy of vagus nerve occurs up to nucleus ambiguus
Stretching of RLN by enlarged intra-thoracic lesions pulls vagus nerve down from skull base, injuring superior laryngeal nerve

31. Cricoarytenoid joint fixation
Vocal cord paralysis
Cricoarytenoid joint fixation
Floppy, vocal cords with bowing
Arytenoids falls antero-medially
Vocal cord at a higher level
Tilting of larynx  paralysed side
Flickering of cord on phonation
Shallow pyriform fossa
Fixed in specific position
Arytenoids can be moved
Absent
In position
Same level
Normal
Any position
Arytenoids fixed

32. Clinical Features

33. Lesion above pharyngeal branch
Inability to elevate soft palate, nasal intonation, nasal regurgitation & nasal emissions
Gag reflex reduced or absent due to palsy of internal branch of superior laryngeal nerve
Hoarseness due to palsy of intrinsic muscles of larynx

34. Asymptomatic (1/3rd unilateral paralysis)
Faint whisper
Functional adductor paralysis
Forced whisper
Organic adductor paralysis
Voice tires with use
Unilateral abductor paralysis
Stridor & aspiration
Bilateral abductor paralysis

35. U/L S.L.N. palsy B/L S.L.N. palsy
Disability in professional voice user only
Voice weak, breathy, inability to raise pitch
Anterior commissural tilt to healthy side
Short & flabby vocal fold
Flapping cord during respiration
Professional voice compromised
Absence of anterior commissural tilt
Cough & choking due to aspiration

36. U/L combined palsy B/L combined palsy
Cord in cadaveric position  hoarseness
Glottic incompetence
 ineffective cough
Partial anesthesia of larynx  aspiration
B/L cords in cadaveric position  aphonia
Total anesthesia of larynx  aspiration + bronchopneumonia

37. Specific Investigations

38. Voice assessment 1. Magnetic tape recording: for self assessment
2. Performance assessment by examiner: maximum phonation time & range of speech frequencies
3. Phonetogram: plot of pitch vs. intensity of voice
4. Aerodynamic analysis: phonatory airflow rate, subglottic pressure & laryngeal resistance

39. Phonetogram

40. Aerodynamic analysis

41. 5. Fourier’s Spectral analysis (Spectrogram)
Fundamental frequency: lowest speech frequency
Shimmer: average cycle to cycle difference in amplitude of sound
Jitter: average cycle to cycle difference in duration of glottal cycle
In hoarseness there is increased shimmers & jitters

42. Spectrogram

43. Shimmer & Jitter

44. Analysis of cord movement
1. Rigid 700 video-telescopy ↓LA
2. Fibreoptic video-laryngoscopy
3. Stroboscopy: Intermittent flash light focussed on vocal cords during phonation. Frequency of light made 2 msec slower to cord frequency. Produces slow motion movement of vocal cords for better analysis of cord movement

45. Video-stroboscopy

46. 4. Electro-glottography: 2 electrodes placed on both sides of thyroid cartilage & current passed b/w them. Recorded waveform shows impedance across larynx & is highest during contact b/w vocal cords. Records closing phase of glottal cycle.
5. Photo-glottography: fibreoptic light source passes light via glottis & is received by photo-sensor on neck skin. Light received  glottic chink. Records opening phase of glottal cycle.

47. Electroglottography

48. Photoglottography

49. Radiological Submento-vertical skull base view
X-ray neck AP & lateral view
Chest X-ray PA view
Barium swallow AP & lateral oblique view
High resolution CT scan with contrast from skull base to mid thorax: gold standard
M.R.I.: ideal for skull base lesions
Thyroid scan

50. Endoscopy 1. Rigid 700 Telescopy ↓ LA 2. Fibreoptic Laryngoscopy ↓ LA
3. Pan-endoscopy ↓ GA (for metastatic node):
a. Nasopharyngoscopy
b. Micro-laryngoscopy: probe test on arytenoids
c. Bronchoscopy & bronchial washings
d. Hypopharyngoscopy
e. Oesophagoscopy

51. Fibre-optic laryngoscopy
paralyzed vocal fold is foreshortened, lateralized & flaccid

52. B/L abductor palsy
Inspiration
Expiration

53. Biopsy for suspected malignancy
1. F.N.A.B. from enlarged lymph nodes
2. Punch biopsy from visible growth
3. Blind biopsy from (if metastatic node present):
Fossa of Rosenmuller
Base of tongue
Pyriform fossa
Laryngeal ventricles
Bronchial carina

54. Respiratory function test
1. Conventional spirometry
2. Flow-Volume Loop analysis
Variable extra-thoracic obstruction: ↓ed inspiratory flow
Intra-thoracic obstruction: ↓ed expiratory flow
Fixed obstruction: ↓ed inspiratory + expiratory flow

55. Flow volume loop analysis

56. Other investigations Blood: ESR, serology for syphilis
Electromyography of intrinsic laryngeal muscles:
a. Normal: Joint fixation, post - scarring
b. Fibrillation: Denervation (bad prognosis)
c. Polyphasic: Synkinesis, Re-innervation (good prognosis)

57. Electromyography

58. Treatment for phonatory gap in U/L abductor or adductor palsy

59. Speech therapy: for 2-12 months (usual treatment) Vocal cord injection: with Teflon / fat / collagen Medialization thyroplasty (Isshiki type I) Arytenoid adduction: for posterior approximation Arytenoidopexy: medial rotation + fixation Laryngeal re-innervation Combination of above

60. Indications for immediate surgical intervention
Electromyography shows fibrillation (complete loss of function with no signs of recovery)
Vocal cord palsy due to nerve entrapment in thyroid / bronchial malignancy where recovery is not expected

61. Per-oral Teflon injection
Kleinsasser’s microlaryngoscope introduced
Bruning’s syringe loaded with Teflon paste
Needle pushed lateral to thyroarytenoid muscle
First injection at postero-lateral angle of middle third of vocal cord, 2.5 mm lateral to cord margin
Second injection (0.2 ml) made at antero-lateral angle till both cords approximate in phonation
I.V. Dexamethasone given for 24 hours

62. Per-oral Teflon injection

63. Vocal fold Teflon injection

64. Percutaneous Teflon injection
Needle introduced in midline through crico-thyroid membrane angled upward & laterally into vocal cord
Direct lateral penetration of larynx through thyroid ala is alternate route of injection
Vocal cord entered under endoscopic control

65. Percutaneous Teflon injection

66. Midline & lateral routes

67. Vocal fold fat injection

68. Vocal fold collagen injection

69. Isshiki’s Thyroplasty
Type 1 (medial displacement)
Type 2 (lateral displacement)
Type 3 (shortening or relaxation)
Type 4 (elongation of tensioning)
Thyroplasty is reversible, does not invade vocal folds nor alters their mass or stiffness unlike vocal fold injection

70. Thyroplasty type I

71. Thyroplasty type I

72. Thyroplasty type I
Horizontal skin incision made over mid-point of thyroid cartilage lamina (from a point 2 cm lateral to midline on opposite side to posterior margin of thyroid cartilage on affected side)
Subplatysmal flaps elevated & strap muscles retracted laterally to expose thyroid cartilage
Window made in thyroid lamina with scalpel or 1 mm cutting burr, as per Koufman’s formula

73. Window’s superior border lies at level with vocal cords (midpoint b/w thyroid notch & inferior margin of thyroid cartilage) & its anterior border situated 8 mm posterior to midline
Cartilage removal started postero-inferiorly
Inner perichondrium elevated off thyroid cartilage & silastic prosthesis inserted
Patient asked to phonate while moving silastic prosthesis into its optimal position under flexible laryngoscopy guidance

74. Type I thyroplasty

75. Koufman’s formula
Window height (mm) = thyroid alar height (mm) –  
Window width (mm) = thyroid alar height (mm) –
Average = 12 X 6 mm (male); 10 X 5 mm (female)

76. Insertion of prosthesis

77. Insertion of silastic prosthesis

78. Silastic implant

79. Arytenoid adduction
Portion of posterior thyroid cartilage margin cut to expose muscular process of arytenoid
Two 4-0 Prolene sutures passed through muscular process & through thyroid cartilage
Sutures pulled parallel to lateral cricoarytenoid
After optimal medialization of vocal fold, sutures tied on external aspect of thyroid lamina

80. Arytenoid adduction

81. Arytenoid adduction

82. Laryngeal re-innervation
Neuromuscular pedicle of superior belly of omohyoid (or sternohyoid) + ansa hypoglossi nerve transferred into thyro-arytenoideus for vocal fold medialization; or posterior crico-arytenoideus for lateralization (Tucker)
Neural anastomosis of ansa hypoglossi nerve directly to recurrent laryngeal nerve (Crumley)

83. Neuromuscular pedicle

84. Neuromuscular pedicle

85. Neuromuscular pedicle

86. Ansa-R.L.N. anastomosis

87. Combination surgeries
Neuromuscular pedicle re-innervation + Thyroplasty type 1
Thyroplasty type 1 + arytenoid adduction
Arytenoid adduction has advantage of posterior glottic approximation unlike thyroplasty

88. Treatment of stridor in B/L abductor paralysis

89. Tracheostomy: temporary / permanent in acute stridor
Vocal cord lateralization: endoscopic, external (King)
Vocal cordectomy: external, endoscopic
Endoscopic vocal cordotomy: knife, cautery, laser
Arytenoidectomy: endoscopic, external (Woodman)
Lateralization thyroplasty (Isshiki type II)
Laryngeal re-innervation: ansa hypoglossi-omohyoid pedicle transfer into posterior crico-arytenoideus

90. Vocal cord lateralization (laterofixation / cordopexy)

91. Vocal cord lateralization
Thyroid cartilage exposed via horizontal incision
16-gauge IV cannula inserted through thyroid cartilage 4 mm anterior & 2 mm below mid-point of oblique line, into laryngeal lumen, just above tip of vocal process, under M.L.S. guidance
Another 16-gauge IV cannula inserted 5 mm below 1st cannula, just below tip of vocal process

92. Vocal cord lateralization
1-0 Prolene suture threaded through inferior cannula into laryngeal lumen
Suture thread brought out with forceps into laryngeal lumen & inserted into superior cannula
External traction put on both suture ends to pull vocal cord laterally to give a 5 mm airway
Threads tied over thyroid lamina 8 times

93. Cordectomy

94. Cordectomy + lateralization

95. Posterior cordotomy

96. Arytenoidectomy

97. Cordotomy + arytenoidectomy

98. Thyroplasty type II (lateralization)

99. Treatment for bilateral adductor paralysis causing chronic aspiration

100. Endolaryngeal stenting (solid & vented)
Epiglottic flap closure
Epiglottopexy to posterior pharyngeal wall
Epiglottic tube laryngoplasty
Glottic closure
Sub-perichondrial cricoidectomy
Tracheo-esophageal diversion
Laryngo-tracheal separation
Narrow field laryngectomy

101. Endolaryngeal stent

102. Epiglottic flap closure

103. Epiglottopexy

104. Epiglottic tube laryngoplasty

105. Glottic closure

106. Subperichondrial cricoidectomy

107. Tracheo-esophageal diversion
Proximal trachea anastomosed with esophagus
Distal trachea opens into permanent tracheostomy

108. Laryngo-tracheal separation
Proximal trachea closed
Distal trachea opens into permanent tracheostomy

109. Narrow field laryngectomy

110. Other procedures for aspiration
Double cuff tracheostomy
Laryngeal suspension
Feeding Gastrostomy
Feeding Jejunostomy
Vocal cord injection
Medialization thyroplasty
Laryngeal re-innervation
Tympanic / Chorda tympani neurectomy

111. Laryngeal suspension

112. Other vocal cord surgeries

113. Thyroplasty type III (shortening)
Used for mutational falsetto

114. Thyroplasty type IV (elongation)
Used for raising vocal pitch & ing vocal tension

115. Evaluation of Hoarseness (dysphonia)

116. Causes of Hoarseness

117. Mechanism of hoarseness
Loss of approximation of vocal cords: in paralysis, fixation or intervening tumor / lesions
Alteration of size of vocal cord: ed in edema, tumor; ed in partial surgical excision, fibrosis
Alteration of stiffness of vocal cord: ed in spasmodic dysphonia, fibrosis; ed in paralysis
Improper vibration of vocal cord: hyperemia, vocal nodule, vocal polyp

118. 10 organic dysphonia 20 organic dysphonia
1. Congenital * 1. Laryngitis *
2. Laryngeal tumor * 2. Vocal nodule
3. Vocal cord palsy 3. Vocal polyp
4. Spasmodic Reinke’s edema
5. Muscular * Functional dysphonia
6. Neurological * 1. Psychogenic
7. Endocrine * 2. Habitual
8. Senile Puberphonia
9. Fixation by arthritis 4. Ventricular *
10. Traumatic * 5. Malingering

119. Congenital: laryngomalacia, laryngocoele, haemangioma, web
Laryngeal tumor: papilloma, malignancy
Muscular: myasthenia gravis
Neurological: Parkinsonism, Multiple sclerosis, cerebro-vascular accident, bulbar palsy
Endocrine: hypothyroidism, inter-sex, pregnancy
Traumatic: accidental, foreign body, intubation
Laryngitis: bacterial, viral, TB, allergic, GERD
Ventricular: dysphonia plica ventricularis

120. History taking
1. Duration: > 3 weeks in pt > 40 years is laryngeal malignancy until proven otherwise
2. Progression: due to mass effect or malignancy
3. Voice quality:
a. Forced whisper: Organic adductor paralysis
b. Faint whisper: Functional adductor paralysis
c. Tires with use: U/L abductor paralysis, myasthenia

121. 4. Associated symptoms:
a. Stridor: B/L abductor paralysis
b. Aspiration: B/L adductor paralysis
c. Dysphagia + exertion dyspnea: Ortner’s syndrome
d. Hemoptysis: lung malignancy, tuberculosis
e. Nasal regurgitation & intonation: high vagal lesion
5. Past history:
a. Trauma: accidental, foreign body, intubation
b. Surgery: thyroid, intra-thoracic
c. Viral upper respiratory tract infection, smoking

122. Physical Examination Listening to patient’s voice: for hoarseness
Indirect laryngoscopy: laryngeal lesions
Otoscopy: rule out glomus tumor
Neck: lymph node enlargement, thyroid disease
Chest: lung malignancy, tuberculosis
Cardiovascular: mitral stenosis
Neurological: Parkinsonism, multiple sclerosis

123. Manual compression test
Improvement in voice = do thyroplasty (anterior
medialization procedure). No improvement in voice = do
arytenoid adduction (posterior medialization procedure)

124. Routine investigations
Fibre-optic laryngoscopy
Microlaryngoscopy: crico-arytenoid joint mobility
CT scan skull base to diaphragm: best
X-ray chest: for hemoptysis
Ba swallow: for dysphagia
Thyroid scan: for thyroid enlargement
Panendoscopy: in presence of hard neck node

125. Thank You