Bell's Palsy Flashcards Preview

Neuro and Stroke > Bell's Palsy > Flashcards

Flashcards in Bell's Palsy Deck (37)
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1
Q

What is Bell’s palsy?

A

An acute, unilateral peripheral facial nerve palsy

2
Q

What are the key features of Bell’s palsy?

A
  • Otherwise unremarkable examination and history
  • Deficit affects all zones equally
  • Fully evolves within 72 hours
3
Q

What features make the palsy NOT Bell’s palsy?

A
  • Known aetiology
  • Progressive palsy
  • Waxing and waning
  • Affect’s facial zones unequally
4
Q

What is the main function of the facial nerve?

A

Motor innervation to the muscles of facial expression

5
Q

What are the additional functions of the facial nerve?

A
  • Sensory fibres from external auditory meatus
  • Taste fibres from the anterior 2/3 tongue
  • Control of salivation
  • Motor fibres to the stapedius
6
Q

What cranial nerve is the facial nerve?

A

CN VII

7
Q

Where is the facial nerve nucleus situated?

A

The brainstem

8
Q

What course does the facial nerve take when leaving the brainstem?

A

Fibres loop around CN VI nucleus and leave the pons medial to CN VIII

9
Q

After leaving the brainstem what does the facial nerve pass through?

A

The internal acoustic meatus

10
Q

After passing through the internal acoustic meatus what bone does the facial nerve enter?

A

Petrous temporal bone via the facial canal

11
Q

What happens to the facial nerve within the facial canal?

A

It widens to form the geniculate ganglion

12
Q

What is the geniculate ganglion responsible for?

A

Taste and salivation

13
Q

Where is the geniculate ganglion situated?

A

The medial side of the middle ear

14
Q

What happens to the facial nerve after the geniculate ganglion

A

It turns sharply and gives off the chorda tympani before emerging through the stylomastoid foramen to supply the muscles of facial expression

15
Q

What is the cause of Bell’s palsy?

A

Unknown - usually occurs after a viral infection

16
Q

What are the risk factors for Bell’s palsy?

A
  • Pregnancy
  • Diabetes
  • Recent URTI
  • Family history
17
Q

What characterises Bell’s palsy?

A

A one-sided facial droop that comes on within 72 hours

18
Q

What functions of the facial nerve may be affected?

A
  • Blinking and closing eyes
  • Smiling and frowning
  • Lacrimation
  • Salivation
  • Flaring nostrils
  • Raising eyebrows
  • Taste sensation of anterior 2/3 tongue
  • Innervation of stapedius muscle
19
Q

What branch of the facial nerve supplies the anterior 2/3 of the tongue?

A

Chorda tympani

20
Q

What branch of the facial nerve supplies the stapedius muscle?

A

Tympanic branch

21
Q

What can happen as a result of impairment to stapedius innervation?

A

Sound sensitivity

22
Q

How common is sound sensitivity in Bell’s palsy?

A

Rare

23
Q

How is Bell’s palsy diagnosed?

A

By excluding other causes i.e. diagnosis of exclusion

24
Q

What are the differentials for Bell’s palsy?

A
  • Ramsay Hunt syndrome
  • Lyme disease
  • Benign facial nerve tumour
  • Malignant facial nerve tumour
  • Blunt force trauma to face or temporal bone
  • Stroke
25
Q

What is Ramsay Hunt syndrome also known as?

A

Herpes zoster otitis

26
Q

Give an example of a benign facial nerve tumour?

A

Facial nerve schwannoma

27
Q

Give an example of a malignant facial nerve tumour?

A

Mucoepidermoid carcinoma of parotid gland

28
Q

What reassurance should be given to patients with Bell’s palsy?

A

Prognosis is good and full recovery is usually made

29
Q

How long does full recovery from Bell’s palsy usually take?

A

3-4 months

30
Q

What advise should be given to patients with Bell’s palsy?

A
  • Keep eyes lubricated with eye drops
  • Tape eyes closed at night with micropore if needed
  • Avoid situations that will irritate eyes
31
Q

What treatment should be given to people with Bell’s palsy within first 72 hours of onset?

A

Oral prednisolone

32
Q

What are the benefits of oral prednisolone in patients with Bell’s palsy?

A
  • Shorten time to recovery

- Improve long-term outcomes

33
Q

What may have additional benefit to corticosteroids if paralysis is severe at presentation?

A

Anti-virals

34
Q

What can be done for Bell’s palsy if certain criteria are met?

A

Surgical decompression by an experienced neuro-otologist

35
Q

What are the potential complications of Bell’s palsy?

A
  • Irreversible damage to the facial nerve
  • Abnormal regrowth of nerve fibres
  • Partial or complete blindness due to eye dryness and corneal scratching when eye won’t close
36
Q

What can happen as a result of abnormal facial nerve fibre regrowth?

A

Synkinesis

37
Q

What is synkinesis?

A

Involuntary contraction of certain muscles when trying to move others