1. Facial nerve disorders
Dr Raymond Ngo
2008

2. Function of the facial nerve
Motor fibers – face and others
Parasympathetic fibers to salivary glands
Taste to anterior 2/3 of tongue
Sensation to skin (periaural)

4. Anatomy of the facial nerve
Intra-cranial - Brainstem to IAC
Meatal – through the IAC to meatal foramen
Labyrinthine – meatal to geniculate
Tympanic – 1st genu to 2nd genu
Mastoid – 2nd geno to stylomastoid
Extratemporal

6. Otoscopic Exam

7. Clinical examination Face – House Brackmann Score Ears
Oral examination
Schirmer’s test

8. Grade
Definition I
Normal symmetrical function in all areas II
Slight weakness noticeable only on close inspection
Complete eye closure with minimal effort
Slight asymmetry of smile with maximal effort
Synkinesis barely noticeable, contracture, or spasm absent
III
Obvious weakness, but not disfiguring
May not be able to lift eyebrow
Complete eye closure and strong but asymmetrical mouth movement with maximal effort
Obvious, but not disfiguring synkinesis, mass movement or spasm IV
Obvious disfiguring weakness
Inability to lift brow
Incomplete eye closure and asymmetry of mouth with maximal effort
Severe synkinesis, mass movement, spasm V
Motion barely perceptible
Incomplete eye closure, slight movement corner mouth
Synkinesis, contracture, and spasm usually absent VI
No movement, loss of tone, no synkinesis, contracture, or spasm

9. Simplified HB Score Grade Definition I Normal II Very mild weakness
III
Obvious weakness, asymmetry of mouth
Complete eye closure
Some spasms IV
Incomplete eye closure
Severe spasms V
Very slight movement only VI
No movement at all

11. Investigations
Audiometry
CT or MRI
ENoG
After day 4
At day 14
Role

12. Electroneuronography

13. ENoG Results Comparison of bad versus good side Response is
(amplitude of bad side / good side) x 100 %
40/750 X 100 = 5.3%
Degeneration is
100 – 5.3% = 94.7% degenerated

14. Patient A 25 year old female
Sudden onset – noticed food dribbling out of left corner of mouth
Friends noticed change in appearance
Rapid worsening over 2 days
No past medical history

15. Bell’s Palsy Start Prednisolone, Acyclovir Protect the eye
Prognosticate with ENoG
Surgical decompression of facial nerve (optional)
Await resolution

17. Patient A +
Notice of ear examination vesicles in the ear canal and pinna
Audiogram shows mild sensorineural hearing loss on left
Patient develops dizziness several days later

19. Ramsay Hunt Syndrome Management same as Bell’s Prognosis less good
Can be part of multiple cranial nerve neuropathy

20. Patient B 30 year old Indian construction worker
Long history of ear problems
Complains of left ear discharge many months
Noticed a gradual onset left facial weakness
Associated hearing loss

21. Mastoiditis Complication
Start antibiotics
Order CT Temporal Bone
Consider myringotomy
Consider mastoidectomy

22. Patient C
70 year old man
Long standing history of right ear hearing loss – does not bother him
Noticed mild weakness of right face

23. Exclude a CPA lesion Rare for CPA lesions to present with facial palsy
Do MRI internal acoustic meatus
Consider the diagnosis of facial nerve schwannoma

24. Patient D 58 year old man History of right parotid lump 1 year
Getting bigger 4 cm but not painful
Mild facial asymmetry

25. Parotid Tumor
A parotid tumor with facial palsy is likely to be malignant
Adenoid cystic especially
Benign tumors rarely affect facial nerve
Facial nerve schwannoma (extra-temporal) maybe very big before palsy appears

26. Patient E 20 year old RTA victim
Sustained skull base injury – suspected
Otorrhoea noted
Referred for investigation of temporal bone fracture
Patient is alert and able to communicate

27. Temporal Fractures Decision to decompress depends on onset of palsy
Immediate onset – need to decompress
Delayed onset – can observe

28. Iatrogenic Facial Injuries
Parotid Surgery
Head and Neck Surgery
Ear Surgery
Lateral Skull Base Surgery

29. Complications of Facial Palsy
Eyes – exposure keratitis
Oral function
Crocodile tears
Cosmesis issues

30. Facial Repair Facial slings Nerve grafting
End to end (sural / greater auricular)
Hypoglossal to facial nerve
Cross innervation