Neurology - facial nerve palsy Flashcards
What is the pathway of the facial nerve?
The facial nerve exits the brainstem at the cerebellopontine angle.
It passes through the temporal bone and parotid gland to innervate the face
Facial nerve function
Motor - supplies muscles of facial expression
Sensory - taste in the anterior 2/3 tongue
UMN vs LMN facial nerve palsy
Each side of the forehead has upper motor neuron innervation by both sides of the brain but only has lower motor neurone innervation from one side (the same side)
In UMN lesion - forehead sparing (able to raise eyebrows)
In LMN lesion - forehead not spared, patient cannot move their forehead on the affected side
What may cause upper motor neurone lesion?
Unilateral - strokes, tumours
Bilateral (rare) - e.g. pseudobulbar palsies and MND
Causes of LMN facial nerve palsy?
Bell’s Palsy
Ramsay Hunt syndrome
Also:
- Infection e.g. OM, malignant OE, HIV, Lyme’s
- Systemic disease e.g. DM, sarcoidosis, MS, leukaemia, GBS
- Tumours - e.g. Acoustic neuroma, cholesteatoma, parotid tumours
- Trauma e.g. damage to nerve in surgery, basal skull fractures
What is Bell’s Palsy?
Idiopathic - no clear cause
Unilateral LMN facial nerve palsy
How long till Bell’s palsy recovery? Prognosis?
Most patients fully recover over several weeks but may take up to a year
A third are left with some residual weakness
Treatment of Bell’s palsy
If patients present within 72h- give prednisolone either:
- 50mg for 10 days
- 60mg for 5 days followed by a 5-day reducing regime of 10mg a day
Lubricating eye drops
Instruction that if they develop pain in the eye they need an ophthalmology review for exposure keratopathy
Can tape eye closed at night
What is Ramsay Hunt syndrome?
Caused by varicella zoster virus (VZV)
Presents as a unilateral lower motor neurone facial nerve palsy with painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side
Treatment of Ramsay Hunt syndrome?
Ideally start treatment within 72h
Prednisolone AND aciclovir
