Facial Nerve

Question 1

What is another name for the facial nerve?

Answer 1

cranial nerve 7

Question 2

What is the function of the facial nerve?

Answer 2

Innervates the motor system of the muscles of facial expression

Question 3

Upper motor neuron lesion/ supranuclear lesion?

Answer 3

• spares the forehead

- usually part of another neurological problem-CVA, multiple sclerosis,brain tumour

Question 4

Lower motor neuron lesion/infra-nuclear course:

Answer 4

1. starts in the nucleus of the brainstem
2. Then it goes into the bony canal of the petrous temporal bone
3. Goes into the labyrinthine portion of the internal auditory canal with vestibulocochlea nerve
4. first genu/turn
5. turns into the horizontal/tympanic portion
6. second genu/turn
7. vertical/mastoid portion
8. It leaves the base of the skull at the mastoid foramen 9. Goes into the parotid gland separates the parotid into superficial and deep lobes
9. divides into 5 branches of facial expression

Question 5

What areas does the facial nerve palsy affect?

Answer 5

1. forehead
2. eyes
3. nose
4. tongue
5. neck

Question 6

Is Bell’s palsy a UMN or LMN lesion?

Answer 6

It is a LMN lesion because the forehead is not spared

Question 7

What about Bell’s palsy is NB?

Answer 7

• Diagnosis of exclusion
• usually resolves in 3 months
• Idiopathic
• loss of hearing, taste, occasional hyperacusis

Question 8

Why is it NB to figure out whether it is a complete or incomplete facial paresis?

Answer 8

To determine the level of recovery and what management we need to do

Question 9

What is the management of bell’s palsy?

Answer 9

1. Reassure patient that it is not CVA
2. Tell them how long it will take to heal- 3 weeks to 3 months
3. Start steroids(1mg/kg PO for 10 days but do not give in DM)
4. Give acyclovir because of the evidence of herpes virus
5. protect the cornea
6. Follow and reasses in 3 months

Question 10

What are the non-traumatic causes of facial nerve palsy other than Bell’s palsy?

Answer 10

1. Labyrinthine- ramsay hunt sydrome,acoustic neuroma,
2. Mesotympanic: TB, choleastatoma, acute otitis media
3. Parotid neoplasms

Question 11

What is herpes zoster otticus or ramsay hunt syndrome?

Answer 11

• shingles
• caused by varicella zoster
• presents with otalgia, vesicles, facial nerve palsy with a worse prognosis, involvement of CN 5,8,9,10,11,12

Question 12

What is the management of trauma of the LMN?

Answer 12

1. If we find it early then early exploration is NB
2. If it presents late then oedema persists and conservative treatment is NB
3. Make sure you do a CT scan