1. Facial Nerve Paralysis
Dr. Vishal Sharma

2. Gabriel Fallopius ( )

3. Anatomy of Facial Nerve
Motor root: 7000 axons
Sensory root (Nervus intermedius / Wrisberg): 3000 axons. Joins motor root at fundus of I.A.C.
Motor: predominantly to facial muscles
Secretomotor: lacrimal, submandibular, sublingual
Taste: anterior 2/3rd of tongue
Sensory: Post-aural / concha / ext. auditory canal

4. Course of facial nerve

10. Parts of facial nerve Intracranial: within cerebello-pontine angle
Intra-temporal
 Meatal segment  Labyrinthine segment
 Tympanic segment  Mastoid segment
Extra-cranial
 Extra-parotid  Intra-parotid (terminal)

11. Segments of Facial Nerve
1. Supranuclear: Fibers in cerebral cortex to brain stem
2. Brain stem: Motor nucleus of facial nerve (pons)
3. Intra-cranial (12 mm): Brain stem to entry into IAC
4. Meatal (10 mm): Within Internal Auditory Canal
5. Labyrinthine (4 mm): Fundus of I.A.C. to Geniculate gangl.
6. Tympanic (11 mm): Geniculate ganglion to pyramid
7. Mastoid (13 mm): Pyramid to stylomastoid foramen
8. Extra-temporal (15 mm): S.M. foramen to pes anserinus

12. Primary branches of facial nerve
Intra-temporal: greater superficial petrosal, stapedius, chorda tympani
Extra-parotid: post-auricular, stylohyoid, posterior belly of digastric
Intra-parotid: temporal, zygomatic, buccal, marginal mandibular, descending cervical

13. Intra-cranial branches

14. Extra-cranial branches

15. Communicating branches to:
Meatal: vestibulo-cochlear
Tympanic: lesser petrosal  otic ganglion
Mastoid: auricular branch of vagus
Extra-parotid: glossopharyngeal, auriculotemporal, vagus, greater auricular, lesser occipital
Terminal: branches of trigeminal

16. Surgical landmarks

17. Cochleariform process: small bony protuberance
(from which tensor tympani muscle turns 900 to insert
into malleus) lies 1 mm inferior to geniculate ganglion
at anterior end of tympanic segment.
Cog: bony ridge hanging from tegmen tympani lies 1
mm above & posterior to cochleariform process.
Incus short process: 2 mm below lies external genu
Lateral Semicircular Canal: 2 mm Antero-Infero-Medial lies external genu
Oval window: 1 mm above lies external genu

18. Inferior edge of Posterior S. C. C
Inferior edge of Posterior S.C.C.: 2 mm anterior & lateral lies mastoid segment of facial nerve
Tympano-mastoid suture in posterior canal wall: 5-8 mm medial lies mastoid segment of facial nerve
Digastric ridge in mastoid tip: leads antero-medially to mastoid segment of facial nerve
Groove between mastoid & bony E.A.C. meatus: bisected by facial nerve
Tragal pointer: 1 cm antero-infero-medial is facial nv
Root of styloid process: lateral lies facial nerve
Superior border of posterior belly of digastric: superior & parallel lies facial nerve

19. Surgical landmarks

20. Lesions of Facial Nerve

21. Lesion Manifestation Supranuclear C/L hemiplegia, ed jaw jerk
Nuclear (pons)
I/L 6th, 7th palsy + C/L hemiplegia
In C.P. Angle
I/L 5th, 7th, 8th palsy
Supra-geniculate
ed lacrimation, hyperacusis, loss of taste
Supra-stapedial
Hyperacusis, loss of taste
Supra-chordal
Loss of taste
Infra-chordal
Facial asymmetry only

24. Upper Motor Neuron Palsy Lower Motor Neuron Palsy
Features
Upper Motor Neuron Palsy
Lower Motor Neuron Palsy
Forehead wrinkling
B/L present
Same side absent
Eye closure
Naso-labial fold
Opposite side absent
Drooping of angle of mouth
Opposite side
Same side

25. Etiology of Facial Nerve Palsy

26. 1. Idiopathic (55%): Bell’s palsy,
Melkersson Rosenthal syndrome
2. Temporal bone trauma (25%): Road traffic accident
3. Infection (10%): C.S.O.M., Herpes Zoster oticus
Malignant otitis externa
4. Neoplasm (5%): Parotid tumors, Acoustic Neuroma,
Glomus tumors, Malignancy of ear
5. Congenital (4%): Moebius syndrome
6. Iatrogenic (rare): Mastoidectomy, Parotid surgery
7. Metabolic (rare): Diabetes mellitus, Hypertension

27. Sunderland’s Classification (1951)

28. Cross section of nerve

30. Partial block of axoplasm Injury to endoneurium or myelin sheath
Grade
Name
Characteristics I
Neuropraxia
Partial block of axoplasm II
Axonotemesis
Injury to axon
III
Neurotemesis
Injury to endoneurium or myelin sheath IV
Partial transection
Injury to perineurium V
Complete transection
Injury to epineurium

31. House Brackmann Classification (1 year post-injury)

32. Grade Characteristics I II III IV V VI
Description
Characteristics I
Normal
Normal facial function II
Mild dysfunction
Slight weakness seen only on close inspection
III
Moderate dysfunction
Obvious asymmetry; complete eye closure IV
Moderately severe dysfunction
Obvious asymmetry; incomplete eye closure V
Severe dysfunction
Only minimal motion seen; asymmetry at rest VI
Total paralysis
No movement

33. House Brackmann grading
Sunderland Grading
EEMG response
Recovery begins in
House Brackmann grading I
Normal
1-4 wks II
25 % of normal
1-2 mth
III
< 10 % of normal
2-4 mth
III or IV IV
No response
4-18 mth V
Never VI

34. Diagnosis Topo-diagnostic Tests Electrical Tests
Magnetic stimulation of intra-cranial facial nerve
CT scan temporal bone: for progressive palsy
MRI brain
Surgical exploration

35. Topo-diagnostic tests
Audiometry: cochlear nerve function
Vestibulometry: vestibular function
Schirmer’s test: Greater Superficial Petrosal Nerve
Stapedial reflex test: Nerve to stapedius
Electrogustometry: Chorda tympani
Submandibular salivary flow: Chorda tympani
Examination for terminal facial nerve branches

37. Schirmer’s Test Unilateral wetness ed by >30% of total amount of
both eyes after 5 minutes =
Schirmer test positive 
lesion at or proximal to
geniculate ganglion

38. Stapedial Reflex

39. Electrogustometry
Measures minimum amount of current required to excite sensation of taste

40. Muscles supplied by terminal branches

42. Electrical tests

43. Nerve Excitability Test
Stimulating electrode used over terminal branches of facial nerve
Minimum current intensity required to produce minimal muscle movement is calculated
Normal side compared to paralyzed side
Difference > 3.5 mAmp = unfavorable prognosis

44. Maximal stimulation test
Stimulating electrode used over terminal branches of facial nerve
Minimum current intensity required to produce maximal muscle movement is calculated
Normal side compared to paralyzed side
Difference > 3.5 mAmp = unfavorable prognosis

45. Electro-neuronography
Terminal branch of facial nerve stimulated & action potential recorded in appropriate muscle
Paralyzed side compared to normal side (which is taken as 100%)
Response > 10% = % chance of recovery
Response < 10% = 25 % chance of recovery

46. Electro-neuronography

47. Electro-neuronography

48. Electro-neuronography

49. Records spontaneous activity of facial muscles
Electromyography
Records spontaneous activity of facial muscles

50. Electromyography Responses
Normal
Polyphasic
Fibrillation
Electrical Silence

51. Response Interpretation
Normal Motor Unit Action Potentials: Incomplete transection of facial nerve
Poly-phasic Motor Unit Action Potentials: Re-innervation of facial muscles
Fibrillation potentials: Denervation of muscles (2-3 weeks after trauma)
Electrical silence: Atrophy / absence of muscle

52. Bell’s Palsy
Acute onset, idiopathic, unilateral, self-limiting, non-progressive, peripheral facial nerve palsy
85% start recovering within 3 weeks
Etiology:
1. Viral: Herpes simplex, Herpes Zoster
2. Ischemia of facial nerve: exposure to cold,
emotional stress, nerve compression
3. Hereditary Autoimmune

53. Sir Charles Bell

54. Clinical Features Loss of forehead wrinkles Inability to close eyes
Wide palpebral fissure
Epiphora
Loss of naso-labial fold
Drooping of angle of mouth
Dribbling of food while chewing on affected side

55. Medical treatment Prednisolone (1mg/kg in 2 doses): for 2 - 3 weeks
Acyclovir: mg 5 times per day X 7days
Eye care: Voluntary 2 / min. Ciplox eye drops 2 hourly & ointment H.S. Eye cover at night.
Physiotherapy: moist heat + facial massage + facial muscle exercise
Electrical stimulation of facial nerve & muscle
Facial nerve decompression: Controversial

56. Moebius syndrome

57. Melkersson Rosenthal Syndrome
Recurrent alternating facial palsy
Fissured tongue
Facio-labial edema
Familial history

58. Melkersson Rosenthal Syndrome

59. Surgical Treatment for Facial Nerve Injury

60. A. Facial nerve decompression: till meatal foramen
B. Neurorrhaphy (Nerve repair)
1. Direct end to end anastomosis
2. Interposition Cable grafting: sural, greater auricular
C. Nerve Transposition: hypoglossal-facial
D. Muscle Transposition: temporalis, masseter
E. Micro-neuro-vascular muscle flaps
F. Static Procedures: eyelid implant, fascial sling

61. Treatment Protocol Up to 3 weeks: Nerve decompression or Nerve repair
3 weeks – 2 year: Nerve Repair or Nerve Transposition
> 2 year with fibrillation in Electromyography: Nerve Repair or Nerve Transposition
> 2 yr with electrical silence in Electromyography: Muscle transposition / Eyelid implant / Fascial sling

62. Facial Nerve Decompression
Cortical mastoidectomy done
Facial nerve canal bone thinned in barber pole fashion with diamond burr. Drilling done:
Posteriorly at mastoid segment, Laterally at external genu & Inferiorly at tympanic segment
Avoids injury to chorda tympani & lateral S.C.C.
Labyrinthine segment decompressed by middle cranial fossa approach

63. Barber Pole

64. Direct repair & Cable Grafting

65. Nerves used for cable grafting

66. Nerve Transposition

67. Nerve Transposition

68. Temporalis muscle transposition

69. Masseter muscle transposition

70. Gold Weight Eyelid Implant

71. Complications of facial nerve injury
1. Incomplete recovery 2. Exposure keratitis
3. Facial tics & spasms
4. Faulty regeneration of facial nerve
a. Synkinesis: Mass movement of facial muscles
b. Crocodile tear syndrome: gustatory lacrimation
Salivary to lacrimal gland cross over
c. Frey’s syndrome: gustatory sweating
Secreto-motor to sympathetic cross over

72. Thank You