Facial nerve palsy Flashcards
What is facial nerve palsy?
Refers to isolated dysfunction of the facial nerve and presents with unilateral facial weakness.
What is the pathway of the facial nerve?
The facial nerve exits the brainstem at the cerebellopontine angle. On its journey to the face, it passes through the temporal bone and parotid gland.
The facial nerve splits into 5 branches, what are these 5 branches?
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
Can be remembered by mnemonic:
- TO ZANZIBAR BY MOTOR CAR
3 main motor functions for facial nerve?
Facial expression
Stapedius in the inner ear
Posterior digastric, stylohyoid and platysma muscles
Sensory function for facial nerve?
Provides taste to anterior 2/3rd of the tongue.
What is the parasympathetic supply of the facial nerve?
Submandibular and sublingual salivary glands
Lacrimal gland (stimulating tear production)
Patients with a lower motor neurone lesion require less urgent treatment compared to those with an upper motor neurone lesion. True/false?
True
Patients with new-onset upper motor neurone facial nerve palsy need immediate management as it can indicate a possible stroke.
In contrast, patients with lower motor neurone facial nerve palsy can be managed less urgently.
The forehead is spared in a lower motor neurone palsy. True/false?
False
The forehead will be spared in an upper motor neurone lesion so the patient can move their forehead on the affected side.
In a lower motor neurone lesion, the forehead is not spared, and the patient cannot move their forehead on the affected side.
What can cause unilateral upper motor neurone lesions?
Cerebrovascular accidents (strokes)
Tumours
What can cause bilateral upper motor neurone lesions?
Pseudobulbar palsies
Motor neurone disease
What does bell’s palsy present with?
Presents with a unilateral lower motor neurone facial nerve palsy.
Most patients fully recover over several weeks, but recovery may take up to 12 months.
What is the cause of bell’s palsy?
Idiopathic (unknown cause)
Treatment of bell’s palsy?
Prednisolone (since it is an isolated facial nerve palsy with no vestibular involvement).
Lubricating eye drops may be required to stop eye from drying out and being damaged.
What is the cause of Ramsey hunt syndrome?
Varicella zoster virus (VZV).
What is the typical clinical presentation for Ramsey hunt syndrome?
Presents as a unilateral lower motor neurone facial nerve palsy.
Patients stereotypically have a painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side.
Rash can also extend to the anterior 2/3rds of the hard palate and tongue.
