1. بسم الله الرحمن الرحيم

2. THE FACIAL NERVE

3. Topics Gross applied anatomy
Pathology of nerve injury and regeneration
Principles of the electrophysiological tests
Causes of facial nerve paralysis
Principles of treatment of facial paralysis
Bell’s palsy

4. Facial Nerve Fibers Motor Secreto-motor (parasympathetic) Taste
to the stapedius and facial muscles
Secreto-motor (parasympathetic)
to the lacrimal gland and the submandibular and sublingual salivary glands
Taste
from the anterior two thirds of the tongue and palate
Sensory
from the external auditory meatus

5. Anatomical Divisions Intracranial Cranial (intratemporal)
Extracranial (extratemporal)

6. The Intracranial Part
Include the nuclei and the Cerebello Pontine angle semgents

7. Facial nerve nuclei

9. Lower motor lesions affect all the ipsilateral facial muscles
Upper motor lesions spare the upper facial muscles and affect the contralateral lower face

10. Upper motor
Lower motor

11. The CP angle segment

12. The Intra-temporal (Cranial)

15. The extracranial part

16. The extracranial part

18. Facial Nerve Fibers Motor Secreto-motor Taste Sensory
to stapedius, and facial muscles
Secreto-motor
to the submandibular, sublingual, and lacrimal glands
Taste
from the anterior two thirds of tongue and palate
Sensory
from the external auditory meatus

19. The secreto-motor and the taste fibres

20. The secreto-motor and the taste fibres

21. Variations and Anomalies

23. Facial Nerve Paralysis

24. Clinical Manifestations
Paralysis of facial muscles
Asymmetry of the face
Inability to close the eye
Accumulation of food in the cheek

28. Clinical Manifestations
Paralysis of facial muscles
Asymmetry of the face
Inability to close the eye
Accumulation of food in the cheek
Phonophobia
Dryness of the eyes
Loss of taste

29. Pathophysiology of Nerve Injury

30. Neuropraxia (Conduction block)
Neurotmeses (Degeneration)

32. Regeneration
In neuropraxia: restoration of full function if the cause is treated
In neurotmeses : No recovery unless the distal and the proximal parts approximated
Recovery is delayed and usually is incomplete

35. Principles of management of facial nerve paralysis
Care of the eye
Treatment of the cause if applicable
Treatment of the nerve varies according to the degree of the paralysis

36. Partial facial paralysis
Being partial means that some of the nerve fibres are in continuity and recovery is expected by conservative treatment (e.g. removal of pressure, steroid etc)

37. Complete facial paralysis
Complete paralysis may be a result of neuropraxia or/and degeneration
If it is due to neuropraxia, recovery is expected by conservative treatment
If it is due to degeneration, surgical treatment is required
To differentiate between degeneration and neuropraxia electrophysiological tests are required

38. Electrophysiological Tests
It detect degeneration of the nerve fibres
Useful only hours following the onset of the paralysis

40. Electrophysiological Tests
Nerve Excitability Test (NET)
Electroneurography (ENoG)

41. Nerve excitability test (NET)
The current’s thresholds required to elicit just-visible muscle contraction on the normal side of the face are compared with those values required over corresponding sites on the side of the paralysis

42. Electroneurography (ENoG)
The amplitude of action potentials in the muscles induced by the maximum current is compared with the normal side ; and used to calculate the percentage of intact axons.

43. Interpretation of the tests
Not useful in the first 48 – 72 hours
After hours (the time required for degeneration to take place)
Normal results means that there is no degeneration (Neuropraxia)
Abnormal results means degeneration

44. Topognostic Tests
Indicated in some cases to locate the site of the injury

45. Topognostic Tests
Schirmer's test
Test the lacrimation function

46. Topognostic tests
Schirmer's test
Stapedial reflex
Taste sensation

47. Topognostic tests
Schirmer's test
Stapedial reflex
Taste sensation

48. Causes of facial paralysis
Intracranial causes
Cranial (intratemporal) causes
Extracranial causes

49. Causes of facial paralysis
Congenital: Birth trauma
Traumatic: Head and neck injuries & surgery
Inflammatory: O.M, Necrotizing O.E., Herpes
Neoplastic: Meningioma, malignancy ear or parotid
Neurological: Guillain-Barre syndrome, multiple sclerosis
Idiopathic: Bell’s palsy

50. Congenital Facial Palsy
80-90% are associated with birth trauma
% are associated with developmental lesions

51. Inflammatory causes of facial paralysis

52. Facial Paralysis in AOM
Mostly due to pressure on a dehiscent nerve by inflammatory products
Usually is partial and sudden in onset
Treatment is by antibiotics and myringotomy

53. Facial Paralysis in CSOM
Usually is due to pressure by cholesteatoma or granulation tissue
Insidious in onset
May be partial or complete
Treatment is by immediate surgical exploration and “proceed”

55. Herpes Zoster Oticus (Ramsay Hunt Syndrome)
Herpes zoster affection of cranial nerves VII, VIII, and cervical nerves
Facial palsy, pain, skin rash, SNHL and vertigo

57. HERPES ZOSTER OTICUS (RAMSAY HUNT SYNDROME)
Herpes zoster affection of cranial nerves VII, VIII, and other nerves
Facial palsy, pain, skin rash, SNHL and vertigo
Vertigo improves due to compensation
SNHL is usually irreversible
Facial nerve recovers in about 60%
Treatment by: Acyclovir, steroid and symptomatic

58. Traumatic Facial Injury
Iatrogenic
Temporal bone fracture

59. Iatrogenic Facial Nerve Injury
Operations at the CP angle, ear and the parotid glands

60. Temporal Bone Fracture
Longitudinal
Transverse

61. Transverse Fracture

62. Pathology
Edema
Transection of the nerve

63. Management of Traumatic Facial Nerve Injury
If it is delayed in onset, it is usually incomplete and is due to edema
Conservative
If of immediate onset, it is usually complete and due to transection of the nerve
Surgical repair

64. SURGICAL REPAIR

65. Surgical repair
Direct anastomosis

66. Surgical repair
Direct anastomosis
Nerve graft

67. Surgical repair Direct anastomosis Nerve graft
Nerve transfer (anastomosis)

68. Surgical repair Direct anastomosis Nerve graft
Nerve transfer (anastomosis)
Muscle Flap

69. Bell’s Palsy Most common diagnosis of acute facial paralysis
Diagnosis is by exclusion

70. Pathology
Edema of the facial nerve sheath along its entire intratemporal course (Fallopian canal)

71. Etiology
Vascular vs. viral

72. Clinical Features Sudden onset unilateral FP Partial or complete
No other manifestations apart from occasional mild pain
May recur in 6 – 12%

73. Prognosis 80% complete recovery 10% satisfactory recovery
10% no recovery

74. Treatment Reassurance Eye protection Physiotherapy
Medications (steroids, antivirals, vasodilators)
Surgical decompression in selected cases

75. Surgical Management Debate over years Patients with 90% degeneration
Within 14 days of onset

76. OFFICE HOURS Prof. YOUSRY EL-SAYED
Flat 407, Building 5 , King Abdel-Aziz Universty Hospital
Mondays from 11 am to 1 pm
Thursdays 11 am to 1 pm

77. THANK YOU