Facial Nerve Disorders

Question 1

Osteopetrosis

Answer 1

Congenital facial paralyses and vision/hearing loss
AD transmission
Bony dysplasia (bones harden) affecting neural foramina
Involving CN II, V, VII, VIII

Question 2

Mobius Syndrome

Answer 2

Congenital hypoplasia of CN VI and CN VII
Bilateral facial paralysis (congenital facial diplegia)
Musculoskeletal deformities
Intellectual disability
Multifactorial inheritance
Caused by exposure to teratogens including:
- cocaine
- ergotamine (vasoconstrictor)
- Misoprostol (vasodilator)

Question 3

Bell’s Palsy

Answer 3

Acute unilateral facial paralysis
- commonly idiopathic
- can be from herpes simplex virus and nerve entrapment from inflammation
- ~5% caused by CN VII schwannoma
Majority of patients recover within 3 to 6 months for patients under 65 years old
A quick return of ARTs on the affected side is a good prognostic indicator

Question 4

Trauma

Answer 4

Include from most common to least:
- temporal bone fractures
- iatrogenic injury (surgical injuries), especially during otosclerosis and cholesteatoma surgeries
- lacerations
- gunshot wounds

Question 5

Malignant otitis externa

Answer 5

Infectious facial nerve disorder caused by bacteria invading soft tissue, cartilage, and bone

Question 6

Acute suppurative otitis media

Answer 6

Infectious facial nerve disorder caused by gram-positive bacteria and Haemophilus influenzae

Question 7

Chronic otitis media with/without cholesteatoma

Answer 7

Infectious facial nerve disorder caused by invasion of the temporal bone causing dehiscence which can lead to edema/inflammation and compression of the facial nerve

Question 8

Herpes zoster oticus (Ramsay-Hunt Syndrome)

Answer 8

Infectious facial nerve disorder
A form of shingles that attacks the facial nerve portion near the ear.
Common manifestations include:
- otalgia
- rash
- facial paralysis
- hearing loss
- vertigo
- degeneration of the facial nerve

Question 9

Facial Nerve Schwannoma

Answer 9

Neuroma on CN VII
Can be misdiagnosed as a vestibular schwannoma because both can present with SNHL (~50% of cases)
ARTs, ABRs, and MRIs and CT scan can be used to help differentiate site of lesion
Site on the nerve can influence symptoms:
- closer to the brainstem has more hearing loss/balance problems
- more lateral causes facial weakness and twitching
Other auditory symptoms include tinnitus, otalgia, otorrhea, and dizziness
Does NOT always present with facial weakness (about 2/3 of cases have facial weakness) especially if it is confined in IAC or CPA