FACIAL NERVE ANATOMY OTORHINOLARYNGOLOGY ENT LANDMARKS OF FACIAL NERVE BLOOD SUPPLY OF FACIAL NERVE FACIAL COLLICULUS SYNDROME

1. Facial nerve

2. FACIAL NERVE
• MIXED NERVE
• PREDOMINANTLY MOTOR
• NERVE OF SECOND BRACHIAL ARCH

3. • SVA  TASTE SENSATION
• GSA  FROM POSTERIOR WALL OF EXTERNAL ACOUSTIC MEATUS
• GVE  SECRETOMOTOR
• SVE BRACHIAL RCHES

9. (Falciform crest )

10. • 7UP  VII CN
• COCOCOLA  COCHLEAR
NERVE
• BB  BILS BAR
• TC  TRANSVERSE CREST

12. Fallopian canal
• From internal acoustic meatus to stylomastoid foramen
• 3 parts
• Labyrinthine
• Tympanic
• Mastoid

13. • LABYRINTHINE
• NARROWEST  SITE OF EDEMA BELLS
PALSY OCCURS IN THIS SEGMENT
• SHORTEST SEGMENT
Narrowest

14. 1st genu /geniculate ganglion
• b/w labrynthine & tympanic segment
• Most common site of injury to facial nerve in trauma

16. Bells palsy
• Involves labyrinthine segment (1st segment)
• As it involves top segment  all functions of facial nerve are lost

17. TYMPANIC OR
HORIZONTAAL
SEGMENT
• EXTENDS FROM
GENICULATE GANGLION
TO HORIZONTAL SCC

18. DEHISCENT CANAL
• MOST COMMON IN TYMPANIC SEGMENT ESPECIALLY ABOVE OVAL
WINDOW

19. DEHISCENT FALLOPIAN CANAL IN TYMPANIC
SEGMENT
• DEHISCENT FALLOPIAN CANAL IN
TYMPANIC SEGMENT
• FACIAL PALSY
• CAN OCCUR IN MIDDLE EAR
INFECTIONS ASOM
• INCREASEED RISK IN SURGERY

20. BRANCHES OF FACIAL NERVE IN
INTRACRANIAL
• GREATER PETROSAL FROM
GENICULATE GANGLION
• FROM SECOND GENU
• NERVE TO STAPEDIUS
• FROM MASTOID SEGMENT 
CHORDA TYMPANI

21. NERVE TO STAPEDIUS
• Causes contraction of stapedius muscle in
response to acoustic stapedial reflex

22. ACOUSTIC STAPEDIAL REFLEX
LOUND SOUND
>70 dB
Bilateral contraction of stapedius muscle

23. • Paralysis of stapedius  hyperacusis

24. Superior olivary nucleus is the centre for
acoustic reflex

25. Mastiod segment of facial nerve
• Most common site of injury to facial nerve in mastoid sx
• In 2nd genu & vertical part

26. Processu cochleariformis correspond to
geniculate ganglion

27. Surface land mark of geniculate ganglion
• Processus cochleariformis
• Bony ridge from medial
wall against which tensor
tympani turns medially
to insert aginst neck of
malleus

28. Surgical land marks of tympanic part
• b/w horizontal scc & oval
window

29. Land marks for mastoid part of facial nerve
• Short process of incus
• Tympanomastoid suture line
• Digastric ridge

30. Surgical landmark of facial nerve in
• Inferior extension of Tragal
• styloid process
• Posterior belly of digastric
• Marginal mandibular nerve
• Tracing retrograde manner

32. Blood supply of facial nerve
• Intracranial AICA
• Intratemporal
• Labyrynthinine branch of AICA
• Petrosal branch of middle meningeal A
• Stylomastoid branch of posterior
auriculr A
• Extratemporal
• Stylomastoid branch of posterior
auricular artery
• Occipital artery
• Transverse facial branch of superficial
temporal artery

34. SVE BRANCHIAL EFFERENT
• ALL MUSCLES OF FASCIAL EXPRESSION (except LPS)
• MUSCLES OF AURICLE
• SCALP
• OCCIPITAL BELLY OF OCCIPITOFRONTALIS
• BUCCINATOR
• PLATYSMA
• STAPEDIUS
• STYLOHYOID
• POSTERIOR BELLY OF DIGASTRIC

36. Motor fibres of facial nerve form facial colliculi by
winding around VIth cranial N nuclei

38. facial colliculus syndrome
• Involvement of ipsilateral facial nerve abducent nerve &
spinothalamic tract

39. PES ANSERINUS

40. PES ANSERINUS

41. THROUGH SUBSTANCE OF PAROTID GLAND

42. PARALYSIS OF
BUCCINATOR
• ACCUMALATION OF FOOD IN MOUTH
AFTER FACIAL PALSY

43. • MARGINAL MANDIBULAR N  MC NERVE INJURED IN PAROTID
SURGERY (SUPPLYING ANGLE OF MOUTH)

47. • Hitselberger sign
• Hypoaesthesia of posterosuperior wall of external auditory canal in an
enlarging acoustic neuroma at internal auditory meatus

50. Exits at crebellopontine angle at lateral
junction

51. Exits at pontomedullary junction

58. Nerve supply to lacrimal gland

79. Facial nerve is also involved in corneal reflex

82. Facial nerve lesions

83. Topognosis
• Schirmer test  for lacrimation
• Electrogustometry taste
• Stapedial reflex 

84. Investigations
• HRCT
• IOC for traumatic facial nerve lesion
• Gd MRI
• IOC for tumours & inflammatory lesion

85. • Upper motor neuron type
• Vascular (Multi infarct dementia)
• Motor neuron disease
• Lower motor neuron type
• Guillain Barre syndrome
• Sarcoidosis – uveoparotid fever(HEERFORDT SYNDROME)
• Leprosy
• Lymphoma / leukemia
• Mobius syndrome
• Botulism

86. Mobius syndrome
d/t fetal brain ischmia
• Direct teratogenic effect of misopristol
• b/l facial palsy
• VI th nerve palsy
• Multiple cranial nerve abnormality
• Malformed extremities
• Lack of pectoral muscles

87. BELLS PALSY
ENT

88. BELLS PALSY
MOST COMMON
IDIOPATHIC
ACUTE RAPID ONSET
LABYRINTHINE SEGMENT
D/T EDEMA  HERPES SIMPLEX TYPE 1 INDUCED{?}
DIAGNOSIS OF EXCLUSION

89. PERSISTENT DEGERNERATION OF NERVE FIBRES FOR 10 DAYS
RECOVERY OF FACIAL NERVE AFTER 10 DAYS
IF NO RECOVERY AFTER 10 DAYS  IT IS NOT BELLS PALSY

90. ETIOLOGY
•VIRAL INFECTIONS : HSV,
•VASCULAR ISCHAEMIA
PRIMARY ISCHAEMIA :COLD/EMOTIONAL STRESS
SECONDARY ISCHAEMIA: PRIMARY ISCHEMIA ↑PERMEABILITY & EDEMA 
COMPRESSION OF MICROCIRCULATION
HEREDITARY (NARROW FALLOPIAN CANAL10% )
AUTOIMMUNE DISORDERS

91. CFs
SUDDEN ONSET
UNABLE CLOSE EYELID
BELLS PHENOMENON ( on attempting to close eyelid eye ball turns up & out)
DRIBBLING OF SALIVA
FACIAL ASYMMETRY
EPIPHORA (tears flowing down eyes)
EAR PAIN b4/during bells palsy
HYPERACUSIS (stapedial palsy)
LOSS OF TASTE (paralysis of chorda tympani)
RECURRENCE

93. DIAGNOSIS
BY EXCLUDING ALL OTHER CAUSES OF FACIAL PALSY
H/O
OTOLOGICAL HEAD & NECK EXAMINATION
XRAY,
RBETBC,PERIPHERAL SMEAR ,ESR
RBS
SEROLOGY
NERVE EXCITABILITY daily/alternate days motor nerve degeneration
TOPODIAGNOSISdetect site

94. TREATMENT
PREDNISOLONE(1mg/kg/day divided into morning & evening doses * 10 days)
ACYCLOVIR 400MG 5 TIMES A DAY FOR 5 DAYS
CARE OF EYE
PHYSIOTHERAPY

95. SURGICAL
NERVE DECOMPRESSION
◦ ONLY WHEN >90 % OF NERVE FIBRES ARE DEGENAERATED IN ELECTRONEUROGRPAHY
◦ NO EMG POTENTIAL

96. PROGNOSIS
85%RECOVERY

97. RAMSAY HUNT SYNDROME
REACTIVATION OF DORMANT HERPES ZOSTER INFECTION IN GENICULATE GANGLION &
VESTIBULAR GANGLION OF VIIITH NERVE
FACIAL PARALYSIS +
VESICULAR RASH ON AUDITORY CANAL /PINNA +
HEARING LOSS & GIDDINESD(8TH NERVE)
TREATMENT
SAME AS BELLS PALSY (EXCEPT ACYCLOVIR 800MG)

98. RAMSAY HUNT SYNDROME
◦ MAY ALSO INVOLVE
◦ TRIGEMINAL
◦ EIGHTH
◦ IXth CN
Only 10 % patients recover completetly after complete loss of function with out treatment

99. MELKERSSONS SYNDROME
RECURRENT FACIAL PARALYSIS +
RECURRENT OROFACIAL EDEMA  SWOLLEN LIPS +
FISSURED TONGUE