Recurrent laryngeal nerve paralysis

RECURRENT LARYNGEAL NERVE

PARALYSIS

BY: NILUFER

For normal voice production:

• 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

ANATOMY OF LARYNX LOCATION : in the middle and ant.part of the neck , opp. C3 - C6

CARTILAGES : 1. paired

2.unpaired

Unpaired : • *epiglottis * thyroid *cricoid Paired : * arytenoid * corniculate * cuneiform

1. ABDUCTORS : Post. cricoarytenoid

2. ADDUCTORS: Lat.cricoarytenoid

interarytenoid Thyroarytenoid3.TENSORS: Cricothyroid4.RELAXERS :

Vocalis Thyroarytenoid (int part)

Acting on l.inlet: 1.OPENERS Thyroepiglottic 2.CLOSERS Interarytenoid (oblique p.)

Aryepiglottic (post. ob. p.)

Extrinsic muscles :• 1. elevators• 2. depressors

NERVE SUPPLY OF LARYNX1. sensory : * above vocal cords - SLN (ILN) * below vocal cords - RLN

2.motor: * all intrinsic muscles - RLN # except . cricothyroid ( SLN - external)

VOCAL CORDS• *DEFN : are pearly white mucous memb.

infoldings that stretch horizontally across mid.laryngeal cavity.

• ATTACHMENTS: Ant : thyroid cartilage Post : arytenoid cartilage ( vocal process) EDGES: Outer - attached to muscle in larynx Inner - free ( form rima glottidis) • TYPES: • 1. TRUE : formed from conus elasticus (inf layer of

infolded membrane)

2. FALSE : formed from quadrangular membrane ( sup. layer of infol.mem )

• ant. 2/3 - membranous

• post 1/3 - cartilagenous

position of vocal cordsnormally : breathing -

abducted phonation -

adducted

swallowing - add.

COURSE OF RLN

vagus - tenth. CNCranial part ; 2 nuclei vagus descends down

exits skull via jugular.f sup. ganglion inf.ganglion descends down and enters

carotid sheath

below inf.gang.

• gives SLN

• at level of hyoid bone it divides into

external internal

at level of SCA - GIVES RIGHT RLN

• at thr level of arch of aorta - gives LEFT• RLN• GALEN 'ANASTOMOSIS: btw SLN &

RLN• NON RECURRENT LARYNGEAL N.• WHY LEFT RLN more prone for

paralysis?

CLASSIFICATION• 1. RLN• 2. SLN• 3. COMBINED

• * 1. CONGENITAL/ ACQUIRED• 2. U/L or B/L• 3. COMPLETE/ INCOMPLETE• 4. ABDUCTOR / ADDUCTOR/ BOTH

5. SENSORY / MOTOR• * ETIOLOGY :• 1. supranuclear • 2. nuclear• 3. vagus nerve ( high vagal )• 4. low vagal trunk • - right RLN• - left RLN• - both• 5. systemic causes

CAUSES OF RLNP• RIGHT : neck• - neck trauma• - thyroid disease• -malignancy• - iatrogenic• - cer. lymphadenopathy• - aneurysm of SCA• - CA.apex rt.lung• - TBofcer.pleura• - idiopathic

LEFT : 1. in the NECK; • - acc.trauma• - thy. disease• - iatrogenic• - malignancy• - c.lymph.• in the MEDIASTINUM ;• - Bronchogenic.CA• - CA.tho.eso• - aortic aneurysm• - M. lymph• - ortner s syn.• - intrathoracic surgry

BOTH ;

• thy.surgry• CA.thyroid• CAcer. oeso• cer. lymphadenopathy

TYPES OF RLNP1. UNILATERAL2. BILATERAL

1.UNILATERAL RLNP : DEFN: Condition which leads to ipsilateral

paralysis of all intrinsic laryngeal muscles except cricothyroid .

INCIDENCE : usually affects adults SEX : both males n females

•clinical • features

THEORIES TO EXPLAIN THE POSITION OF VOCAL CORDS IN PARALYSIS

• 1. SEMON 'S LAW : • "in all the prog. org. lesions,

abd.fibres of nerve which are phylogenetically newer, are more susceptible & are first to be paralysed compared to adductors.

• 2. WAGNER AND GROSSMAN 'S LAW

" cricothyroid muscle ( supplied by SLN)which has adductor function, keeps cord in paramedian position."

VOCAL CORDS

PM pure RLNP

C comb.palsy

• ETIO : • - BRONCHOGENIC CA.• - THYROID SURGERY

C/F : - VOICE - POSITION OF VOCAL CORDS - RESPIRATION ( stridor) - SWALLOWING ( aspiration )

• 1. VOICE : - asympotomatic in 1/3 cases - left sided; hoarseness -no change - improves gradually by compensation

2. POSITION OF VC : median or paramedian - aff. vc may lie at a lower level

3. no prob. of aspiration or breathing

INVESTIGATIONS :• 1. Chest X-Ray • 2. biopsy• 3. radiography of barium swallow• 4. panendoscopy - dir.laryngoscopy,

bronchoscopy, esophagoscopy• 5. blood sugar• 6. VDRL• 7. ESR• 8. neurological invest.• 9. CVS • 10. CT- SCAN and MRI

MANAGEMENT : - if asymptomatic - no trtmnt reqd,. - temporary paralysis recovers in 6 to 12

months - advisable to wait - voice improvement during waiting period - 1. speech therapy -

• if paralysis persists for 9 to 12 months, then following procedures performed:

• 1. laryngoplasty type 1 with vc inj.• 2. laryngoplasty type 2 with arytenoid

adduction• 3. thyroplasty type 1 - medialization of vc• - make window through

thy.cartilage• then implant silastic prosthesis

BILATERAL RLNP ( ABDUCTOR PARALYSIS)

DEFN: condition in which al the intrinsic muscles of larynx are paralysed bilaterally. except cricothyroid

ETIO : neuritis thyroid surgery C/F : - Acute in onset - dyspnea - stridor

• - becomes worse during exertion and infection

• voice : good • position of vc: median / paramedian

INVESTIGATIONS MANAGEMENT : 1. Surgical treatmnt

2 modalities; 1. permanent tracheostomy

with speaking valve 2. lateralization of cord

• by endoscopy or ext.cervical approach• 1.arytenoidectomy• 2. arytenoidopexy• 3.transverse cordotomy ( kashima op.)• 4. thyroplasty type 2 • 5. reinnervation

thyroplasty

• type 1. - medialization

• type 2 . - lateralization

type 3. - vc. are relaxed (shortening)

type 4 . - vc. are tensed

reinnervation

• innervate the paralysed post. cricoarytenoid muscle by

• implanting nerve muscle pedicle from sternohyoid or omohyoid with its n.s. from ansa cervicalis.