Neurology - Facial Nerve Palsy

Question 1

What does facial nerve palsy refer to?

Answer 1

Isolated dysfunction of the facial nerve presenting with unilateral facial weakness

Question 2

Where does the facial nerve exit the brainstem?

Answer 2

At the cerebellopontine angle

Question 3

Which structures does the facial nerve pass through on its way to the face?

Answer 3

Temporal bone and parotid gland

Question 4

What are the five branches of the facial nerve?

Answer 4

• Temporal
• Zygomatic
• Buccal
• Marginal mandibular
• Cervical

Question 5

What is the motor function of the facial nerve?

Answer 5

• Facial expression
• Stapedius in the inner ear
• Posterior digastric, stylohyoid and platysma muscles

Question 6

What sensory function does the facial nerve provide?

Answer 6

Taste from the anterior 2/3 of the tongue.

Question 7

Which glands receive parasympathetic supply from the facial nerve?

Answer 7

• Submandibular and sublingual salivary glands
• Lacrimal gland (stimulating tear production)

Question 8

How are upper and lower motor neurone facial nerve palsys managed?

Answer 8

Upper - immediate management as possible stroke

Lower - can be managed less urgently

Question 9

Why is the forehead spared in UMN lesions?

Answer 9

Each side of the forehead has UMN innervation by both sides of the brain

Each side of the forehead only has lower motor neurone innervation from one side of the brain

In UMN lesion one side is knocked out but still innervated by other side, so UMN lesions forehead is spared by LMN not spared

Question 10

What are the potential causes of upper motor neurone lesions?

Answer 10

Unilateral UMN lesion
* Strokes
* Tumours

Bilateral UMN lesions (rare)
* Pseudobulbular palsies
* MND

Question 11

What is Bell’s palsy?

Answer 11

A relatively common idiopathic condition presenting with unilateral lower motor neurone facial nerve palsy

Question 12

How long does it take patients to recove in Bell’s palsyr?

Answer 12

Most patients fully recover over several weeks, but recovery may take up to 12 months

Third of patients left with residual weakness

Question 13

What treatment does NICE recommend for Bell’s palsy if patients present within 72 hours?

Answer 13

• 50mg prednisolone for 10 days
• 60mg prednisolone for 5 days followed by a 5-day reducing regime, dropping the dose by 10mg per day

Question 14

What additional care do patients with Bell’s palsy require?

Answer 14

Lubricating eye drops to prevent drying out and eye damage

May need ophthalmology review for exposure keratopathy, eye can be taped closed at night

Question 15

What is Ramsay-Hunt syndrome caused by?

Answer 15

The varicella zoster virus (VZV)

Question 16

What are the characteristic symptoms of Ramsay-Hunt syndrome?

Answer 16

Unilateral lower motor neurone facial nerve palsy with a painful vesicular rash in the ear canal, pinna and ear on affected side

Rash can extend to anterior two-third of the tongue and hard palate

Question 17

What is the treatment for Ramsay-Hunt syndrome?

Answer 17

• Aciclovir
• Prednisolone
• Lubricating eye drops

Question 18

What infections can cause LMN facial nerve palsy?

Answer 18

Otitis media
Otitis externa
HIV
Lyme disease

Question 19

List some systemic diseases that can cause lower motor neurone facial nerve palsy

Answer 19

• Diabetes
• Sarcoidosis
• Leukaemia
• Multiple sclerosis
• Guillain–Barré

Question 20

What types of tumours can lead to lower motor neurone facial nerve palsy?

Answer 20

• Acoustic neuroma
• Parotid tumour
• Cholesteatoma

Question 21

What trauma events can cause lower motor neurone facial nerve palsy?

Answer 21

• Direct nerve trauma
• Surgery
• Base of skull fractures