Vocal cord palsy & evaluation of

hoarsenessDr. Vishal Sharma

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

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

Development of arterial arches

Final position of B/L RLN

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

Dual innervation of inter-arytenoid muscles

ClassificationA. 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

Causes of laryngeal paralysis

Supra-nuclear

Nuclear: nucleus ambiguus

High vagal lesions: combined palsy

Low vagal lesions: recurrent laryngeal nerve palsy

Systemic causes

Idiopathic

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

Etiology of recurrent laryngeal nerve palsy

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

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

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

Causes of B/L RLN palsy (10%)

• Thyroid surgery

• Ca thyroid

• Cancer cervical esophagus

• Cervical lymphadenopathy

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

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

Joll’s triangle for SLN

Beahr’s triangle for RLN

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

Position of vocal cord

Distance from centre

Healthy Diseased

Median Midline Phonation RLN paralysis

Paramedian 1.5 mm Strong whisper

RLN paralysis

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

--

Position of vocal cords

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.”

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

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

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

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

Modern theory

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

Intermediate position of vocal cords in RLN palsy ?

Vocal cord paralysisCricoarytenoid

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. Fixed in specific position

8. Arytenoids can be moved

1. Absent

2. In position

3. Same level

4. Absent

5. Absent

6. Normal

7. Any position

8. Arytenoids fixed

Clinical Features

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

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

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

• Voice weak, breathy,

inability to raise pitch

• Absence of anterior

commissural tilt

• Cough & choking due

to aspiration

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

• Glottic incompetence

ineffective cough

• Total anesthesia of

larynx aspiration +

bronchopneumonia

Specific Investigations

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

Phonetogram

Aerodynamic analysis

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

Spectrogram

Shimmer & Jitter

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

Video-stroboscopy

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.

Electroglottography

Photoglottography

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

Endoscopy1. 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

Fibre-optic laryngoscopy

paralyzed vocal fold is foreshortened, lateralized & flaccid

B/L abductor palsy

Inspiration Expiration

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

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

Flow volume loop analysis

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)

Electromyography

Treatment for phonatory

gap in U/L abductor or

adductor 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

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

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

Per-oral Teflon injection

Vocal fold Teflon injection

Percutaneous Teflon injection

Needle introduced in midline through crico-

thyroid membrane angled 300 - 450 upward &

laterally into vocal cord

Direct lateral penetration of larynx through

thyroid ala is alternate route of injection

Vocal cord entered under endoscopic control

Percutaneous Teflon injection

Midline & lateral routes

Vocal fold fat injection

Vocal fold collagen injection

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

Thyroplasty type I

Thyroplasty type I

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

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

Type I thyroplasty

Koufman’s formula

Window height (mm) = thyroid alar height (mm) – 4 ------------------------------------- 4  

Window width (mm) = thyroid alar height (mm) – 4 ------------------------------------ 2

Average = 12 X 6 mm (male); 10 X 5 mm (female)

Insertion of prosthesis

Insertion of silastic prosthesis

Silastic implant

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

Arytenoid adduction

Arytenoid adduction

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)

Neuromuscular pedicle

Neuromuscular pedicle

Neuromuscular pedicle

Ansa-R.L.N. anastomosis

Combination surgeries

Neuromuscular pedicle re-innervation +

Thyroplasty type 1

Thyroplasty type 1 + arytenoid adduction

Arytenoid adduction has advantage of posterior

glottic approximation unlike thyroplasty

Treatment of stridor

in B/L abductor

paralysis

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

Vocal cord lateralization (laterofixation / cordopexy)

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

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

Cordectomy

Cordectomy + lateralization

Posterior cordotomy

Arytenoidectomy

Cordotomy + arytenoidectomy

Thyroplasty type II (lateralization)

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

• Sub-perichondrial cricoidectomy

• Tracheo-esophageal diversion

• Laryngo-tracheal separation

• Narrow field laryngectomy

Endolaryngeal stent

Epiglottic flap closure

Epiglottopexy

Epiglottic tube laryngoplasty

Glottic closure

Subperichondrial cricoidectomy

Tracheo-esophageal diversion

Proximal trachea

anastomosed with

esophagus

Distal trachea opens

into permanent

tracheostomy

Laryngo-tracheal separation

Proximal trachea

closed

Distal trachea

opens into

permanent

tracheostomy

Narrow field laryngectomy

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

Laryngeal suspension

Other vocal cord surgeries

Thyroplasty type III (shortening)

Used for mutational falsetto

Thyroplasty type IV (elongation)

Used for raising vocal pitch & ing vocal tension

Evaluation of Hoarseness (dysphonia)

Causes of Hoarseness

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

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 4. Reinke’s edema

5. Muscular * Functional dysphonia

6. Neurological * 1. Psychogenic

7. Endocrine * 2. Habitual

8. Senile 3. Puberphonia

9. Fixation by arthritis 4. Ventricular *

10. Traumatic * 5. Malingering

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

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

History taking

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

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

Manual compression testImprovement in voice = do thyroplasty (anterior

medialization procedure). No improvement in voice = do

arytenoid adduction (posterior medialization procedure)

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

Thank You