Respiration Airway protection phonation

Normally : breathing - abduction phonation - adduction

swallowing - adduction

VOCAL CORDS must :

1. be able to approximate with each other 2. have proper size and stiffness 3. have an ability to vibrate reg. in response

to air column

in vocal cord palsy ; - loss of approximation of vc - decreased stiffness of vc

Superior laryngeal nerve-internal branch is sensory supplies larynx above the level of vocal cords and external branch supplies cricothyroid muscle.

Recurrent laryngeal nerve-Motor branch supplies all muscles of larynx except the cricothyroid and sensory branch supplies subglottis

Right RLN arises from vagus, hooks around subclavian artery and ascends upwards in tracheo-oesophageal groove

Left RLN arises from vagus, hooks around arch of aorta and ascends upwards in tracheo-oesophageal groove

Left RLN has longer course thus its prone for injury

Arises in inferior ganglion of vagus, descends behind internal carotid artery and at the level of greater cornua of hyoid it divides into internal and external branches

May be unilateral or bilateral and may involve Recurrent laryngeal nerve Superior laryngeal nerve Both recurrent and superior laryngeal

nerve (combined or complete paralysis)

Supranuclear: Rare Nuclear: involvement of nucleus ambiguus in

medulla, usually associated with other lower cranial nerve paralysis

High vagal lesions: may be involved at the level of jugular foramen or parapharyngeal space

Low vagal or RLN Systemic causes: diabetes mellitus,

diphtheria, typhoid, lead poisoning Idiopathic: in about 30% of cases

Unilateral Results in ipsilateral paralysis of all

intrinsic muscles except the cricothyroid Vocal cord assumes a median or

paramedian position and does not move laterally on deep inspiration

This law explains median or paramedian position of the vocal cords

• It states that ‘In all progressive lesions of RLN, In all progressive lesions of RLN, abductor fibres of the nerve, which are abductor fibres of the nerve, which are phylogenetically newer, are more susceptible and phylogenetically newer, are more susceptible and thus first to be paralysed compared to adductor thus first to be paralysed compared to adductor fibresfibres’

It states that cricothyroid muscle which receives innervation from superior laryngeal nerve keeps the cord in paramedian position due to adductor function

May be undetected as 1/3rd of patients remain asymptomatic

Some patients may complain of change of voice

Voice gradually improves due to compensation by healthy cord which crosses the midline to meet paralysed one

Treatment: Generally treatment is not required

Direct medialization of the vocal cord Performed alone or with

arytenoid adduction or reinnervation procedure

Implant material Carved or prefabricated Silastic

implant Hydroxyapatite implant Gore-Tex strips

Bilateral RLN paralysis Aetiology: neuritis and trauma

(thyroidectomy) are the most common causes. The condition is often acute in onset

Position of cords: as all the intrinsic muscles are paralysed the vocal cords lie in median or paramedian position due to unopposed action of cricothyroid

AETIOLOGY POSITION OF CORDS

CLINICAL FEATURES

TREATMENT

NeuritisSurgical trauma (thyroidectomy)

Paramedian position of both the cords

Good VoiceStridor – Degree VariableDyspnoea

Dyspnoea and stridor become worse on exertion or during an attack of acute laryngitis

Tracheostomy

Cord lateralisation:1.Arytenoidectomy2.Cord lateralisation through endoscope3.Thyroplasty type II4.Cordectomy5.Nerve muscle implant (sternohyoid muscle with its nerve supply is transplanted into the paralysed posterior cricoarytenoid)

Aim to move and fix the cord in lateral position to improve the airway

Various procedures are Arytenoidectomy: can be done by external approach,

endoscopic or by using LASER Thyroplasty type 2 Cordectomy: can be done through external,

endoscopic or by using LASER Nerve muscle implant: sternohyoid muscle with its

nerve supply is transplanted into the paralysed posterior cricoarytenoid to bring some movement

• Unilateral Unilateral Usually it’s a part of combined paralysis,

isolated lesions are rare Causes paralysis of cricothyroid muscle and

ipsilateral anesthesia of the larynx above the vocal cord

Voice is weak and pitch can not be raised Occasional aspiration may be present Askew position of glottis as anterior

commissure is rotated to the healthy side Shortening of the cord with loss of

tension As tension of the cord is lost , it sags

down during inspiration and bulges up during expiration

• Bilateral Bilateral This is uncommon condition Both Cricothyroids are paralysed along with

anesthesia of upper part of larynx Etiology: surgical, accidental trauma,

neuritis, neoplastic (pressure by metastatic lymph nodes)

Clinical features: weak and husky voice, aspiration causing cough and choking fits

Depends on cause, neuritis recovers spontaneously

Troublesome aspiration requires tracheostomy with cuffed tube and esophageal feeding tube

Epiglottopexy is an operation to close laryngeal inlet to protect the lungs from repeated aspiration, it’s a reversible process

• UnilateralUnilateral This causes paralysis of all the muscles of larynx on

one side except interarytenoid which receives innervation from the opposite side

EtiologyEtiology: thyroid surgery is the most common cause

It may also occur in the lesions of nucleus ambiguus or that of the vagus nerve proximal to origin of SLN

Thus lesion may lie in medulla, posterior cranial fossa, jugular foramen or parapharyngeal space

• Clinical features:Clinical features: Vocal cord will lie in cadeveric position Healthy cords fails to compensate This causes hoarseness of voice and

aspiration of liquids through the glottis Cough is ineffective due to air waste

Speech therapy Procedures to medialise the cord Injection of Teflon paste Thyroplasty type 1 Muscle or cartilage implant Arthrodesis of cricothyroid joint

• Bilateral Bilateral Both RLN and SLN are paralysed on both

sides Both cords lie in cadeveric position and there

is total anaesthesia of the larynx

Clinical features

Dysphonia Aspiration Inability to cough Bronchopneumonia

• Treatment:Treatment: Tracheostomy Epiglottopexy: epiglottis is folded backwards

and fixed to the arytenoids Vocal cord plication Total laryngectomy

May be unilateral or bilateral Unilateral is more common May be due to birth trauma, congenital

anomalies of great vessels of heart Bilateral paralysis may be due to

hydrocephalus, arnold-chiari malformations, intracerebral hemorrhage during birth, meningocoele, nucleus ambiguus agenesis

AETIOLOGY POSITION OF CORDS

CLINICAL FEATURES

TREATMENT

Discussed above Median or paramedian position

Does not move laterally on deep inspiration

No symptoms Initial hoarseness

(disappears) Aspirate liquids Weak cough Voice gradually

improves due to compensation by the healthy cord

Generally no treatment required

AETIOLOGY POSITION OF CORDS

CLINICAL FEATURES

TREATMENT

NeuritisSurgical trauma (thyroidectomy)

Paramedian position of both the cords

Good VoiceStridor – Degree VariableDyspnoea

Dyspnoea and stridor become worse on exertion or during an attack of acute laryngitis

Tracheostomy

Cord lateralisation:1.Arytenoidectomy2.Cord lateralisation through endoscope3.Thyroplasty type II4.Cordectomy5.Nerve muscle implant (sternohyoid muscle with its nerve supply is transplanted into the paralysed posterior cricoarytenoid)

AETIOLOGY LARYNGEAL FINDINGS

CLINICAL FEATURES

TREATMENT

Thyroid surgeryTrauma to neckTumorsNeuritisDiphtheria

Askew position of glottis as anterior commissure is rotated to the healthy side

Shortening of cord with loss of tension

The paralysed cord appears wavy due to lack of tension

Flapping of the paralysed cord

Voice is weak

Pitch cannot be raised

Anaesthesia of the larynx on one side may pass unnoticed or cause occasional aspiration

AETIOLOGY LARYNGEAL FINDINGS

CLINICAL FEATURES

TREATMENT

Very rare

Both cricothyroid muscles are paralysed along with anaesthesia of upper larynx

•Surgical or accidental trauma•Neuritis (mostly diphtheritic)•Pressure by cervical nodes•Involvement in a neoplastic process

Absence of anterior tilt allows the epiglottis to hang more over endolarynx.

Slightly flaccid, bowed and hyperaemic vocal cord.

Voice is weak and husky

Cough and choking fits due to inhalation of food and pharyngeal secretions

Depends on cause:•Neuritis : May recover spontaneously•Repeated aspiration: Tracheostomy with a cuffed tube and oesophageal feeding tube•Epiglottopexy: Operation to close the laryngeal inlet to protect the lungs from repeated aspiration

AETIOLOGY LARYNGEAL FINDINGS

CLINICAL FEATURES

TREATMENT

Thyroid surgery (most common)

Lesions of the nucleus ambiguus

Lesions of the vagus nerve proximal to the origin of the SLN (lesions in the medulla, posterior cranial fossa, jugular foramen or parapharyngeal space)

Vocal cord in cadaveric position

The healthy cord is unable to approximate the paralysed cord, thus causing glottic incompetence

Hoarseness of voice

Aspiration of liquids

Weak cough

Speech therapy

Procedures to medialise the cord:1.Injection of teflon paste lateral to paralysed cord2.Thyroplasty type I3.Muscle or cartilage implant4.Arthrodesis of cricoarytenoid joint

AETIOLOGY LARYNGEAL FINDINGS CLINICAL FEATURES TREATMENT

Rare Both cords lie in cadaveric position

All laryngeal muscles are paralysed

Total anaesthesia of the larynx

Dysphonia

Aspiration

Inability to cough

Bronchopneumonia due to repeated aspiration and retention of secretions

Tracheostomy

Epiglottopexy

Vocal cord plication

Total laryngectomy (in cases where the cause is progressive and irreversible and speech is unserviceable)

Diversion procedures

Surgical procedures designed to improve quality of voice

Excision of benign or malignant lesions by Microlaryngeal surgery or laser

Teflon paste injection to vocal cords Thyroplasty Laryngeal reinnervation procedures: segment

of anterior belly of omohyoid muscle carrying its nerve and vessels is implanted into thyroarytenoid muscle

• ISSHIKI CLASSIFICATIONISSHIKI CLASSIFICATION Type 1: Medialization …Type 1: Medialization … Type 2: Lateralization…Type 2: Lateralization… Type 3: Shortening……..Type 3: Shortening…….. Type 4: Lengthening Type 4: Lengthening

( tightening) ………………( tightening) ………………