Facial nerve palsy

Question 1

Causes

Answer 1

Damage to the facial nerve in the temporal bone:
– Bell’s palsy
– trauma
– herpes zoster
– middle ear infection

These all may be associated with undue sensitivity to sounds and loss of taste to the anterior 2 thirds of the tongue

^^ this is because of the 2 branches of the facial nerve

the facial nerve is very motor and supplies the muscle of facial expression

There are 2 branches:
– chords tympani- carries taste from the anterior two thirds of the tongue

– nerve to the stapedius muscle- has a damping affect to protect the ear from loud noises

Question 2

Bell’s palsy

Answer 2

Common, acute, isolated unilateral facial nerve palsy, that is probably the result of a viral infection (often herpes simplex) that causes swelling of the nerve within the petrous temporal bone.

Peak incidence is between the ages of 65 and 74 years.

Is more common in pregnancy

Question 3

Upper motor neuron lesion causes

Answer 3

An UMN lesion causes weakness of the lower part of the face on the side opposite the lesion.

Most common cause is a stroke

Question 4

Lower motor neuron lesions causes

Answer 4

A unilateral LMN lesion causes weakness of all the muscles of facial expression on the same side of the lesion.

Question 5

Clinical presentation

Answer 5

Weakness of facial muscles

Decreased saliva (dry mouth)

Decrease ability to cry

Sometimes loss of taste in anterior two thirds of the tongue

And hypersensitivity to loud noises