Vocal cord paralysis and evaluation of hoarseness

1. Dr. Krishna Koirala
Vocal cord paralysis and evaluation of
Hoarseness
2020-04-15

2. Vocal cord paralysis
• Inability of one or both vocal cords to move
• Due to damage to the nerves going to the vocal cords or damage to the
brain itself
• Common disorder, symptoms can range from mild to life threatening

3. Surgical
anatomy
• Phonation initiated by area 4 in the Sylvian fissure of the
cerebrum
• Peripheral vagal trunk – roots emerging from lower pons and
upper medulla
• Passes through the jugular foramen beside the jugular vein,
posterior to IX and anterior to the XI cranial nerves
• High in the neck it produces the superior laryngeal nerve
• Passes through the neck in the carotid sheath , gives
recurrent laryngeal nerve in the neck

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

5. 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

6. Classification
• Incomplete paralysis
− Recurrent laryngeal nerve palsy
• Left (75% ), Right (15%), B/L (10%)
• Abductor, Adductor
− Superior laryngeal nerve palsy
• Combined paralysis / complete paralysis

7. Etiology of vocal cord paralysis
• Trauma (35%)
• Surgical Trauma (20%) : Esophageal, Lung, Thyroid, Cardiac, Neck, Carotid
• Non-Surgical (15%) : RTA, Sports, Blunt Trauma
• Malignancies (25%) : Bronchial, Esophageal Thyroid, Nasopharyngeal, Neck nodes
• Idiopathic (15%) : Viral Neuritis
• Neurological (15%) : Multiple sclerosis, Amyotrophic Lateral sclerosis, Syringomyelia,
parkinsonism, Head injury, Alcoholic and diabetic Neuropathy
• Inflammatory (5%) : Tuberculosis, Syphilis
• Miscellaneous (5%) : Rheumatoid arthritis, Hemolytic Anemia, Collagen Vascular
diseases, left atrial enlargement (Ortner’s syndrome)

8. • Right recurrent laryngeal nerve is more superficial
• Right nerve enters the 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
Why is right RLN commonly damaged in thyroid
surgery?

10. Theories of vocal fold paralysis
• Semon’s Law (Rosenbach & Semon) : 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.
• Wagner’s and Grossman’s Theory
• Superior laryngeal nerve has an adductive effect through the cricothyroid
• Immobile vocal fold
• Para median position -Total pure unilateral RLN paralysis
• Lateral position - Combined paralysis of superior and rec. laryngeal nerve

11. Modern Thinking
• Final position of paralyses vocal cord is not static and results from
− Degree of muscle atrophy
− Degree of Re- enervation
− Extent of Synkinesis
• Why are the ABDUCTORS affected first ?
• Nerve fibres supplying the abductors are in periphery
• Muscle bulk for the abductors is less, so more susceptible to trauma
• Phylogenetically, larynx’s main function is protection, so functions of the adductors
are maintained

12. Clinical Features
• Lesion above pharyngeal branch
−Inability to elevate soft palate, nasal intonation & nasal regurgitation
−Gag reflex reduced due to palsy of internal branch of superior laryngeal
nerve
−Hoarseness due to palsy of intrinsic muscles of larynx

13. Superior laryngeal nerve palsy
• Disability of voice seen in singers only
• Voice is weak & breathy
• Inability to raise pitch of voice (loss of timbre)
• Cough & choking due to aspiration caused by laryngeal anesthesia (especially in B/L
palsy)
• Vocal cord bowed & floppy with phonatory gap. Anterior commissure pushed to
healthy side & posterior commissure to paralyzed side (Askew position of glottis)

15. Unilateral combined palsy Bilateral combined palsy
I/L cord in cadaveric position 
hoarseness
B/L cords in cadaveric position
 aphonia
• Partial anesthesia of larynx 
aspiration
• Total anesthesia of larynx 
aspiration +
bronchopneumonia

16. Specific Investigations
• Analysis of vocal cord movement
− Rigid 700 video - telescopy
− Fibreoptic video-laryngoscopy
− Stroboscopy:
• Intermittent flashlight focussed on vocal cords during phonation
• Frequency of light made 2 m sec slower to cord frequency
• Produces slow motion movement of vocal cords for better analysis of cord
movement

18. Vocal cord paralysis Cricoarytenoid joint fixation
1. Floppy, vocal cords with bowing
2. Arytenoids falls antero-medially
3. Vocal cord at a higher level
4. Tilting of larynx  paralysed side
5. Flickering of cord on phonation
6. Shallow pyriform fossa
7. Cord fixed in specific position
8. Arytenoids mobile during MLS
1. Absent
2. In position
3. Same level
4. Absent
5. Absent
6. Normal
7. Any position
8. Arytenoids fixed

19. B/L adductor Palsy B/L abductor Palsy

20. Radiology:
• 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

21. Pan - Endoscopy
• Performed for vocal cord palsy associated with metastatic lymph
nodes
• Consists of:
–Nasopharyngoscopy
–Micro-laryngoscopy
–Bronchoscopy & bronchial washings
–Hypopharyngoscopy
–Esophagoscopy

22. Biopsy for suspected malignancy
• FNAC from enlarged lymph nodes
• Punch biopsy from visible growth
• Blind biopsy from (if metastatic node present)
− Fossa of Rosenmuller
− Retromolar trigone
− Base of tongue
− Pyriform fossa
− Laryngeal ventricles
− Bronchial carina

23. Treatment for phonatory gap in U/L palsy
• 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

25. Isshiki’s Thyroplasty
• Type 1 (medial displacement)
• Type 2 (lateral displacement)
• Type 3 (shortening or relaxation)
• Type 4 (lengthening or tensioning)
−Thyroplasty is reversible, does not invade vocal folds nor alter
their mass or stiffness unlike vocal fold injection

26. • Neuromuscular pedicle of superior belly of omohyoid (or sternohyoid)
+ ansa hypoglossi nerve transferred into thyro-arytenoid for vocal fold
medialization
• Neural anastomosis of ansa hypoglossi nerve directly to recurrent
laryngeal nerve (Crumley)
Laryngeal re-innervation

27. Neuromuscular pedicle Ansa RLN Anastomosis

28. Treatment of stridor in B/L abductor paralysis
• Tracheostomy: temporary / permanent
• Vocal cord lateralization: endoscopic, external (King)
• Lateralization Thyroplasty (Isshiki type II)
• Endoscopic vocal cordotomy: knife, cautery, laser
• Vocal cordectomy: endoscopic
• Arytenoidectomy: endoscopic, external (Woodman)
• Laryngeal re-innervation: ansa hypoglossi-omohyoid pedicle transfer into posterior
crico-arytenoid

30. Treatment for bilateral adductor paralysis causing
chronic aspiration
• Endolaryngeal stenting (solid & vented)
• Epiglottic flap closure
• Epiglottopexy to posterior pharyngeal wall
• Epiglottic tube laryngoplasty
• Glottic closure
• Double cuff tracheostomy
• Tracheo- esophageal diversion
• Laryngo-tracheal separation
• Narrow field laryngectomy

32. Evaluation of Hoarseness (dysphonia)

33. Causes of Hoarseness
• Congenital : laryngomalacia, web, hemangioma
• Inflammatory: bacterial, viral, TB, allergic, GERD
• Traumatic : accidental, foreign body, intubation
• Neoplastic : papilloma, malignancy
• Non neoplastic : Vocal nodule, vocal polyp, Reinke’s edema
• Neurological: Parkinsonism, multiple sclerosis, cerebro-vascular accident, bulbar palsy
, myasthenia gravis
• Endocrine : Hypothyroidism, inter-sex, pregnancy
• Functional : Puberphonia, plica ventricularis, malingering

34. History Taking
Duration: > 3 weeks in pt > 40 years is laryngeal
malignancy until proven otherwise
Progression : malignancy, vocal nodules, GERD
Voice quality
Forced whisper: Organic adductor paralysis
Faint whisper: Functional adductor paralysis
Tires with use: U/L abductor paralysis, myasthenia

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

36. 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 (LA
ENLARGEMENT)
NEUROLOGICAL:
PARKINSONISM, MULTIPLE
SCLEROSIS

37. Manual compression
test
• Improvement in voice : Thyroplasty
(anterior medialization procedure)
• No improvement in voice :
Arytenoid adduction (posterior
medialization procedure)

38. Routine Investigations
• Fiber-optic laryngoscopy
• Micro laryngoscopy : crico-arytenoid joint mobility
• Contrast CT scan (skull base to diaphragm): best
• X-ray chest: for hemoptysis
• Ba swallow: for dysphagia
• Thyroid scan: for thyroid enlargement
• Pan endoscopy: in presence of metastatic neck nodes