- This seems to be a lower motor neuron paralysis of the facial nerve.
- The exact cause is unknown, but there is evidence to suggest a viral infection (commonly preceding the palsy) may be responsible.
- The patient presents with unilateral weakness of the face (including the forehead)
- may have problems with lubrication of the eye and dribbling
- Hyperacusis is also seen in around a third of patients.
- Post auricular pain
- Altered taste
- Bell’s palsy is a diagnosis of exclusion.
- The treatment is steroids (prednisolone 25mg for 10 days if started within 72 hours) and most patients will recover in 6 months
- However, particularly if untreated, a significant number will have long-term impairment
Ramsay Hunt Syndrome
- Defined as varicella zoster virus infection of the head and neck involving the facial nerve. It is usually reactivated herpes zoster disease from latent VZV that has resided in CN VII’s geniculate ganglion.
- Deep otalgia often precedes a vesicular rash of the external ear canal and surrounding area
- Often the rash will precede involvement of CNVII and other nerves
- CNVII- unilateral facial weakness (including the forehead) and loss of taste to the anterior 2/3rds of the tongue
- CN VIII- hearing loss/tinnitus / vertigo
- CN IX, X, V and VI may also be affected (rarer)
- There may also be fever, headache and other symptoms (but never without the above features)
- Treatment should be with corticosteroids (prednisolone) and antivirals (aciclovir) and should be started ASAP to avoid permanent damage. There is a worse prognosis than that of Bell’s palsy. Most patients will recover to a degree, but less than half will recover fully.
Other causes of facial weakness may include stroke or brain tumour (in both causes, because they are causing damage at the cortical level, usually the forehead is spared because the facial nerve receives bilateral innervation at this level).