Bell's Palsy

Question 1

What is Bell’s palsy?

Answer 1

An acute, unilateral, idiopathyic facial nerve paralysis

Question 2

What is the peak incidence of Bell’s palsy?

Answer 2

20-40 years

Question 3

What group of patients is Bell’s Palsy most common in?

Answer 3

Pregnant women.

Question 4

What causes Bell’s palsy

Answer 4

Unknown.

Question 5

What are some features of Bell’s palsy?

Answer 5

1. Lower motor neuron facial nerve palsy - forehead is affected.
   
   • Upper motor neuron lesions spare the forehead.
2. Post-auricular pain (50%)
3. Dry eyes
4. Altered taste
5. Hyperacusis

Question 6

What is the prognosis if untreated?

Answer 6

15% of patients have permanent moderate to severe weakness

Question 7

Describe the management plan for Bell’s palsy.

Answer 7

1. Prednisolone for 10 Days if within 72 hours of onset.
   
   1. 1mg/kg (max 80mg) for 5 days
   2. Then 5 Days of reducing dose by 10mg/day.
2. Adding aciclovir gives no additional benefit.
3. Eye care - artificial tears and eye lubricants.

Question 8

What cranial nerve is affected in Bell’s palsy?

Answer 8

The facial nerve

Question 9

What are some differential diagnoses for a lower motor neurone facial nerve palsy other than Bell’s palsy?

Answer 9

• Ramsay-Hunt Syndrome - severe ear pain +/- sensorineural hearing loss and vertigo. There may be vesicles in the ear.
• Otitis media - ear pain +/- fever and otorrhoea
• Cholesteatoma - persistent malodorous otorrhoea. Conductive hearing loss +/- vertigo.
• Temporal bone fracture
• Parotid gland tumours - pain or numbness.
• Guillain-Barre syndrome - Associated limb weakness.
• Lyme disease - history of bite or rash.
• Iatrogenic - post surgery.

Question 10

What can you use to assess the extent of facial weakness?

Answer 10

The House-Brackmann facial nerve grading system.

(With the visual representation being particularly useful)

Question 11

How do you distinguish between an upper and lower motor neurone lesion?

Answer 11

Ask the patient to wrinkle their forehead.

In a lower motor neurone lesionthe patient willnot be able to wrinkle their forehead on the affected side.

In an upper motor neurone lesion the patient is able to wrinkle their forehead.

Question 12

Why does the forehead wrinkle in an upper neurone lesion but not in a lower neurone lesion?

Answer 12

The upper facial motor nucleus receives input from both cerebral cortices.

The lower facial motor nucleus only receives input from the contralateral hemisphere.