Facial Nerve Palsy

Question 1

Facial nerve pathway (Two Zebras Broke My Car for branches of facial nerve)

Answer 1

• Exits brainstem at the cerebellopontine angle
• Passes through temporal bone and parotid gland
• Divides into 5 branches to supply face:
  
  • Temporal
  • Zygomatic
  • Buccal
  • Marginal mandubilar
  • Cervical

Question 2

Functions of the facial nerve

Answer 2

• Motor
  
  • Muscles of facial expression
  • Stapedius in the inner ear
  • Posterior digastric, stylohyoid and platysma muscles in the neck
• Sensory
  
  • Taste to anterior 2/3 of the tongue
• Parasympathetic
  
  • Submandibular and sublingual salivary glands
  • Lacrimal gland (stimulating tear production)

Question 3

Upper vs lower motor neurone lesion

Answer 3

• UMNL - forehead will be spared
• LMNL - forehead will not be spared

NB - Important because UMNL should be referred urgently with suspected stroke.

Question 4

Upper motor neurone lesions

Answer 4

• Unilateral
  
  • CVA
  • Tumours
• Bilateral (rare)
  
  • Pseudobulbar palsies
  • MND

Question 5

Bell’s palsy

Answer 5

• Idiopathic
• Most fully recover but can take up to 12 months
• If patients present within 72 hours of developing symptoms give prednisolone for 10 days
• May also require lubricating eye drops if eyelids cannot close properly

Question 6

Ramsay-Hunt syndrome

Answer 6

• Cuased by HZV
• Stereotypical tender vesicular rash in ear canal, pinna and around ear on affected side
• Treatment should be within 72 hours with prednisolone and aciclovir
• May require lubricating eye drops