Facial Nerve Palsies

Question 1

what are the intracranial branches of the facial nerve?

Answer 1

1. greater superficial petrosal (lacrimation)
2. Branch to stapedius (lesions above this cause hyperacusis),
3. the chorda tympani (supplies taste to anterior 2/3 of the tongue

Question 2

what are the extracranial branches of the facial nerve?

Answer 2

(all motor fibres that branch after emerging from the stylomastoid foramen), posterior auricle nerve, branch to posterior belly digastric muscle and stylohyoid muscle. Parotid contains: temporal zygomatic, buccal, marginal mandibular, cervical

Question 3

what are the different types of causes of facial nerve palsy?

Answer 3

Intracranial
Infratemporal
Intertemporal
Others

Question 4

what are the intracranial causes of facial nerve palsy?

Answer 4

brainstem, tumours, stroke, polio, MS, cerebellopontine angle lesions (acoustic neuroma, meningitis)

Question 5

what are the infratemporal causes of facial nerve palsy?

Answer 5

otits media, ramsay hunt syndrome, cholesteatoma

Question 6

what are the intertemporal causes of facial nerve palsy?

Answer 6

parotid tumours, trauma

Question 7

what are the other causes of facial nerve palsy?

Answer 7

lymes disease, sarcoid, diabetes, Bell’s Palsy

Question 8

what is the differentiating feature between UMN and LMN facial nerve palsy?

Answer 8

UMN spares the forehead

LMN affects all facial muscles

Question 9

what investigations should be done for facial nerve palsy?

Answer 9

• ESR, glucose, lyme disease serology
• Parotid for lumps, ears for cholesatoma and ramsay hunt syndrome
• MRI – space occupying lesions, CVA, MS, temporal bone fracture