Facial Nerve (7th)

Question 1

What does it do?

Answer 1

Sensory: anterior 2/3 tongue
Motor: expression and stapedius

Question 2

Causes of 7th nerve palsy: Unilateral, LMN

Answer 2

Bell’s palsy
Ramsay Hunt
Stroke/demyelination of 7th nerve nucleus in pons
CPA lesion
infection: Lyme disease, TB
Infiltration: sarcoid lymphoma
Vasculitis

Question 3

Pathway of the facial nerve

Answer 3

Pons (wraps around 6)
CPA (with 8, then 5+6)
Internal auditory meatus (with 8)
Facial Canal (chordi tympani and nerve to stapedius have branch off)
Stylomastoid foramen
Branches in temporal zygomatic, buccal, mandibular, cervical

Question 4

Differentials for unilateral facial nerve palsy and how you differentiate each one?

Question 5

Causes of a bilateral nerve palsy

Answer 5

GBS
MG
Bilateral bells
Sarcoid
Lyme disease