Facial nerve palsy

Question 1

Facial nerve palsy refer to isolated dysfunction of the facial nerve - how does this normally present?

Answer 1

Unilateral facial weakness

Question 2

What is the suspected diagnosis in a patient with an UMN facial nerve palsy?

Answer 2

Stroke

Question 3

How does the UMN and LMN innervation of the forehead differ?

Answer 3

Each side of the forehead has UMN innervation by both sides of the brain, but LMN innervation for each side of the forehead is only from 1 side of the brain

Question 4

How can you differentiate an UMN lesion and a LMN lesion of the facial nerve?

Answer 4

In an UMN lesion the forehead will be spared (patient can move their forehead on the affected side), whereas in a LMN lesion the forehead won’t be spared (patient can’t move their forehead on the affected side)

Question 5

Name 3 features of a facial nerve palsy

Answer 5

• Loss of nasolabial fold
• Drooping of eyelid
• Sagging of mouth
• Speech difficulties
• Food trapped between gum and teeth
• Drooling

Question 6

1) Name a cause of a unilateral UMN lesion
2) Name a cause of a bilateral UMN lesion

Answer 6

1) Strokes, tumours
2) MND, pseudobulbar palsies

Question 7

Name 3 causes of LMN lesions

Answer 7

• Bell’s palsy
• Ramsay-Hunt syndrome
• Acoustic neuroma
• Parotid tumours
• MS
• Diabetes
• Sarcoidosis
• Otitis media
• HIV
• Lyme disease

Question 8

Bell’s palsy
1) Name 2 features of Bell’s palsy
2) What is the cause of Bell’s palsy?
3) If given <72 hrs after presentation, what medication can be given for Bell’s palsy?
4) What else is important in the management of Bell’s palsy?

Answer 8

1) Complete unilateral facial weakness, altered taste, dry eyes, post auricular pain
2) Idiopathic - no known cause
3) Prednisolone
4) Lubricating eye drops to prevent the eye on the affected drying out

Question 9

Ramsay-Hunt syndrome
1) What causes this syndrome?
2) What is the typical feature of this condition?
3) Name 2 other features
4) Treatment should be initiated in 72hrs with which 2 drugs?

Answer 9

1) Varicella zoster virus
2) Painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side
3) Loss of taste, tinnitus, vertigo, dry mouth/eyes
4) Acyclovir and prednisolone