This document discusses the anatomy and nerve supply of the larynx. It describes the vagus nerve and its branches, including the recurrent laryngeal nerve. It discusses various types of laryngeal nerve palsies, including their causes, symptoms, examinations findings, and treatments. It provides details on the motor and sensory innervation of different parts of the larynx. Surgical procedures for treating laryngeal paralysis and techniques for vocal fold injection are also summarized.

1. Dr.ASHLY ALEXANDER
ENT PG RESIDENT
GMC,BHOPAL

2.  Nerve supply of larynx

3.  10th cranial nerve
 So called due to its vague course through the
head, neck, thorax and the abdomen.
 Longest nerve of the autonomic nervous
system in the body
 MIXED NERVE: sensory, motor and
parasympathetic

5. Jugular
Foramen

7.  Arises from inferior ganglion of the Vagus
 Descends behind the internal carotid artery
 At the level of greater cornua of hyoid bone,
divides into external and internal branches
 External Motor branch: Cricothyroid muscle
 Internal Sensory branch: Pierces thyrohyoid
membrane and supplies sensory innervation to
larynx above vocal cord.

8. Right
 Arises from the Vagus, at the level of Subclavian artery
 Ascends between the trachea and oesophagus
Left
 Arises from Vagus in mediastinum
 At the level of Arch of Aorta
 Then ascends into the neck in the trachea-oesophageal
groove.
 Thus, Left recurrent laryngeal nerve has a much longer
course which make it more prone to paralysis compared
to the right one. ( About 75%)

11. Motor Supply
 All intrinsic muscle : Recurrent Laryngeal Nerve
Except, The Cricothyroid Muscle : External
Laryngeal Nerve –the branch of Superior
Laryngeal nerve
Sensory Supply
 Above the vocal cords: Internal Laryngeal
Nerve –the branch of Superior Laryngeal Nerve
 Below the vocal cords: Recurrent Laryngeal
Nerve

12. Laryngeal
Palsy
Nerve
involved
Partial/
Incomplete
RLN
RIGHT
(15%)
LEFT
(75%)
B/L (10%)
SLN
U/L
B/L
Combined /
Complete
location
High Vagal
Combined
palsy
Low Vagal RLN Palsy

13. Right Left Both
Neck trauma Neck trauma Thyroid surgery
Benign or malignant
thyroid ds.
Benign or malignant
thyroid ds.
Carcinoma thyroid
Ca cervical esophagus Ca cervical esophagus Ca cervical esophagus
Cervical LAP Cervical LAP Cervical LAP
Aneurysm of
subclavian A.
Bronchogenic ca.
Ca apex right lung Ca thoracic
oseophagus
Mediastinal LAP
TB of cervical pleura Aortic aneurysm
Intrathoracic sx

14. Common Recurrent laryngeal
nerve palsy = Left
MCC of RLN Palsy-
Bronchogenic carcinoma
Common Recurrent Laryngeal
Nerve Palsy during
Thyroidectomy= Right

15.  U/L paralysis of all muscles except cricothyroid
C/F :
 Asymptomatic - one third
 Change in voice which gradually improves due to
compensation by healthy cord.
 Tiring voice
 Diplophonia
O/E
 Affected VC in median/paramedian position.

16. Semon’s Law
 “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 and Grossman
hypothesis
 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

17. Position of
cord
Location
from midline
Health Disease
Median midline Phonation
Paramedian 1.5 mm Strong
whisper
RLN
paralysis
Intermediate
(cadaveric)
3.5 mm Neutral
position
Both RLN
and SLN
nerves
Gentle
abduction
7 mm Quite
respiration
Paralysis
of
adductors
Full
abduction
9.5 mm Deep
inspiration

18. Treatment
 Asymptomatic – spontaneous recovery
 Speech therapy
 Intracordal inj of teflon paste
 Medialization thyroplasty

20.  Abductor paralysis. There is unopposed action of
cricothyroid muscle
Etiology – thyroidetomy (mc), trauma, neoplasm
C/F
 Acute onset
 Dyspnoea and inspiratory stridor which becomes
worst on exertion or infection
 Aspiration in elderly
 Patient may retain good voice
O/E
 Both VC in median or paramedian position, immobile,
flabby, flickers on phonation

22. Diagnosis – CT, MRI ,Chest X Ray,
Panendoscopy, Stroboscopy, Barium swallow
Treatment
 Intubation/emergency tracheostomy
 Permanent tracheostomy with a speaking
valve – to retain good voice
 Lateralisation of VC – VC is moved and fixed in
lateral position which improves airway. Not
preferred in patients with good voice as voice is
lost

23. Partial arytenoidectomy
 Medial part of arytenoid is excised with laser.
Sometimes only the vocal process of arytenoid
is ablated

24.  Arytenoidectomy – removal of arytenoid by external
approach (woodman’s operation), by endoscopic approach
(thornell operation)
 Endoscopic CO2 LASER cordotomy ( Kashima Operation)
Soft tissue at the junction of membranous cord and vocal
process of arytenoid is excised laterally with laser, which
provides good airway.
 Endoscopic CO2 LASER cordectomy
 Laterialisation thyroplasty Type 2
 Nerve muscle implant – sternohyoid muscle with nerve
supply is transplanted into post cricoarytenoid
 Arytenoidopexy ( fixing the arytenoid in lateral position)

26.  Rare
 Paralysis of unilateral cricothyroid muscle
 Unilateral supraglottic anaesthesia
Etiology – thyroid surgery, tumours, trauma, neuritis
C/F
 Weak and low pitch voice (loss of tension)
 Occasional aspiration (anaesthesia)
O/E
 I/L VC flabby and bowed, wavy appearance
 Oblique laryngeal inlet
 Post commissure deviated medially towards
affected side

27. Prognosis
 Voice recovered by compensation from healthy
cord
 Singers cant produce high pitch voice
Treatment
 Speech therapy
During ligation of Superior thyroid vessels in thyroid
surgeries, the dissection should stay close to the
thyroid to avoid nerve damage.
External branch of superior laryngeal nerve lies
posteromedial to the thyroid vessels and should be
identified and preserved.

28.  Least common
 Both cricothyroid paralysed
 Anaesthesia of supraglottic larynx
Etiology – surgical trauma, RTA, neoplasm
C/F
 Coughing and choking during swallowing due to
aspiration
 Weak and husky/breathy voice
 Short phonation time
O/E
 B/L flaccid and bowed VC
Electromyography
of the cricoithyroid
muscle helps to
diagnose the
condition.

29. Treatment
 Ryle’s/NG tube feed
 Tracheostomy with cuffed tube
 Thyroplasty Type 1
 Injection teflon/collagen for medialization
 Epiglottoplexy – reversible procedure where
in laryngeal inlet is closed to protect the lungs
from aspiration. Epiglottis is fixed to
arytenoids

31. Intracranial :
 Intracranial Tumors of posterior fossa
 Basal meningitis(tubercular)
 Skull base Fractures
Skull base:
 Nasopharyngeal cancer
 Glomus tumour
 Neck Penetrating injury
Neck :
 Parapharyngeal tumours
 Metastatic nodes
 Lymphoma

32.  Paralysis of all unilateral muscles except interarytenoid
which receive innervation from other side
Etiology – high vagal lesions, thyroid surgery
C/F
 Hoarseness of voice
 Aspiration of fluids
 Inadequate cough (d/t air wastage)
O/E
 Unilateral paralysed VC in cadaveric position

33. Prognosis
 No compensation by healthy cord
Treatment
 Speech therapy
 Medialisation of paralysed vc by teflon
injection or thyroplasty

34.  Rare
 Total anaesthesia of larynx
 All laryngeal muscles paralysed
Etiology
 Neoplasm in skull base, medulla, upper neck
 CNS disorder
C/F
 Aphonia – VC dont approximate
 Aspiration – laryngeal anaesthesia
 Inability to cough leading to collection of secretions
 Bronchopneumonia due to aspiration and secretions

35. O/E
 Both VC in cadaveric position
Treatment
 Ryle’s tube feed
 Reversible
 Tracheostomy with cuffed tube
 Epiglottoplexy
 VC plication – approximation of VC with sutures
 Irreversible
 Total laryngectomy – for progessive and irreversible
disease, when voice is lost- to protect lungs

36.  Second mc cause of stridor in neonates (1st laryngomalacia)
 Unilateral mc, Right VC
Etiology
 Idiopathic
 U/L – birth trauma, congenital anomaly of heart or vessel
 B/L – anomalies of CNS, hydrocephalus, meningitis
C/F
 Weak or hoarse cry
 Inspiratory or biphasic stridor
 Difficulty in feeding
Prognosis – 70% U/L and 50% B/L recover
spontaneously within six months

37. Diagnosis
 Awake flexible laryngoscopy
 MRI
 X Ray Neck/Chest
Treatment-
 NG tube feed
 U/L (if severe aspiration or dyspnoea)
 Inj teflon/thyroplasty
 B/L (after 5 yrs of age if recovery has not
happened)
 Arytenoidectomy (endoscopic/external)
 Endoscopic lateral cordotomy

38. “any surgery designed primarily for the
improvement or restoration of the voice”

39.  Microlaryngoscopic Surgery
 Vocal Fold Injection
 Laryngeal Framework Surgery
 Nerve Grafting / Rennervation Surgery

40.  Manual Compression Test

41. Type of Anesthesia
Local - allows patient to phonate
 Careful administration of IV sedation
 Internal br. of superior laryngeal nerve is blocked
at the thyrohyoid membrane
 Glossopharyngeal nerve block at the inferior pole
of the tonsils
 Flexible endoscope allows visualization
 Pt sitting and injecting through cricothyroid
membrane

42. General
 Visualizaation problems d/t ETT
 Abnormal anatomical position of neck
 Lack of pt feedback

43.  Adds fullness to the vocal cord to help it
better oppose the other side
 Injection technique is similar regardless of
material used
 Injection into thyroarytenoid/vocalis
 Injection can be done endoscopically or
percutaneously

44.  External landmarks –
several mm anterior
to oblique line
horizontally,
midpoint between
thyroid notch and
inferior thyroid
border vertically

48.  Teflon
 Fat
 Glycerine
 Collagen
 Silicone gel
 Hyaluronic Acid
 Calcium Hydroxyapatite gel

49. Teflon
 Polymer of Tetrafluroethylene
 Produces localised inflammmatory response
 Irreversible
 Used in persons with short life expentency
 Poor long term voice results
 High density & injected deep into
thyroarytenoid muscle
 Risk of granuloma formation

50. Fat
 Autogenous material
 Easily harvested, readily available, no FB reaction
 Overcorrection is necessary – about 50%
 Resorption in months to years

51. Glycerine
 Completely reversible
 Absorbed in 2-6 wks
 Injected deep within vocal fold
Collagen
 Natural constituent of lamina propria
 Bovine collage used
 Skin testing required

52.  Over injection
 Airway compromise
 Under injection
 Misplacement & migration (silicon)
 Granuloma (teflon)

56. First described by Payr and reintroduced by Ishiki
in 1974
Variety of materials used for implants:
 Autologous Cartilage
 Silastic
 Hydroxyapatite
 Gortex
 Titanium
Useful for anterior glottic gap

57.  Type I thyroplasty- medialization of VC.
 Type II thyroplasty- lateralization of VC.
 Type III thyroplasty- shortening or relaxation of VC.
It lowers pitch of voice, done in mutational falsetto or
in those who have gone gender transformation from
female to male
 Type IV thyroplasty- lengthening of VC to elevate
pitch. It is also used when vocal cord is lax and bowing
due to aging process on trauma.

64. Advantages:
 Permanent, but surgically reversible
 No need to remove implant if vocal function
returns
 Excellent at closing anterior gap
Disadvantages:
 More invasive
 Poor closure of posterior glottic gap

65. Complications
 Extrusion/Displacement (Intraoperative or Postop)
 Misplacement – most often superior
 Infection
 Undercorrection – important to overcorrect by 1-2mm
Controversies
 Location of graft placement
 Status of inner perichondrium
 Many series have shown low extrusion rate with
sacrificed perichondrium

67.  First described by Ishiki with modifications by
Zeitels and others
 Addresses posterior glottic gap by pulling
arytenoid into adducted position
 Difficult to predict which patients will benefit
preoperatively.
 Most advocate use in combination with anterior
medialization

71. Endoscopic Approaches:
Suture Placed to Cricoid Cartilage
 Simulates action of lateral cricoarytenoid
Zeitels Modification – Arytenopexy
 Presumably allows a more physiologic positioning of the
arytenoid
 Involves suturing the arytenoid in a more posterior and
medial position to allow more tension on flaccid cord
 Cricothyroid subluxation mimics action of cricothyroid muscle
 Modifications should be used selectively

72. Complications
 Sutures too tight – may displace arytenoid
complex anteriorly, adversely affecting voice
 Entry in pyriform sinus

73.  Open method – lateral / Median approach
 Vocal fold abduction
- Suture technique
- Thyroarytenoid myectomy

77.  RLN anastomosis first described by Horsely in
1909
 Crumly showed Ansa cervicalis to RLN
anastomosis

78.  Results in synkynetic
tone of vocal cord
 Ansa to Recurrent
Laryngeal Nerve
 Ansa to Omohyoid to
Thyroarytenoid

79.  Hypoglossal to recurrent laryngeal nerve
 Crossed nerve grafts or wire conduction
prostheses from one muscle to its paralyzed
counterpart are being researched

81. THANK YOU