Facial Nerve Palsy

Question 1

What is a facial nerve palsy

Answer 1

Facial nerve palsy refers to isolated dysfunction of the facial nerve. Typically presents with an unilateral facial weakness.

Question 2

Describe the facial nerve pathway

Answer 2

The facial nerve exits the brainstem at the cerebellopontine angle. It passes through the temporal bone and parotid gland. It then divides into five branches that suppply different areas of the face:

• temporal
• sygomatic
• buccal
• marginal mandibular
• cervical

Question 3

What is the function of the facial nerve?

Answer 3

3 functions: motor, sensory and parasympathetic

• motor: supplied muslces of facial expression, the stapedius in the inner ear and the posteroir digastric, stylohyoid and platysma muscles in the neck
• sensory: carries taste from the anterior 2/3 of the tongue
• parasympathetic: submandibular and sublingual salivary glands, lacrimal gland

Question 4

Difference betwen UMN and LMN facial weakness

Answer 4

• In UMN lesion the forehead is spared and should be referred immediately with suspected stroke
• In LMN lesion the forehead will not be spared and the patient cannot move their forehead - can be managed in community

Question 5

What are the causes of an unilateral UMN lesion?

Answer 5

• cerebrovascular accidents (stroke)

- tumours

Question 6

What are examples of bilateral UMN

Answer 6

VERY RARE

• pseudobulbar palsies
• MND

Question 7

What is Bell’s palsy

Answer 7

• unilateral LMN facial nerve palsy
• majority fullt recove, 1/3 have residual weakness
• if presents within 72 hours give steroids
  
  • 50mg for 10 days
  • 60mh for 5 days followed by a 5 day reducing regime of 10mg a day
• patient also given lubricating eye drops
• if eye pain develop - need opthalmology review for exposure keratopathy

Question 8

What is Ramsay-Hunt syndrome?

Answer 8

• causes by HZV
• unilateral LMN facial nerve palsy
• ## painful and tender vesicular rash in ear canal, pinna and around the ear on the affected side. This rash can extend to the anterior 2/3 of the tongue and hard palate

Question 9

Management of Ramsay Hunt syndrome

Answer 9

Treatment shoudl be intiated within 72 hours

• treat with prednisolone and aciclovir
• lubricating eye drops

Question 10

Infectious causes of LMN facial nerve palsy

Answer 10

Otitis media
Malignant otitis externa
HIV
Lyme’s disease

Question 11

Systemic disease that cause LMN facial nerve palsy

Answer 11

Diabetes
Sarcoidosis
Leukaemia
Multiple sclerosis
Guillain–Barré syndrome

Question 12

Tumour causes of LMN facial nerve palsy

Answer 12

Acoustic neuroma
Parotid tumours
Cholesteatomas

Question 13

Trauma causes of LMN facial nerve palsy

Answer 13

Direct nerve trauma
Damage during surgery
Base of skull fractures