Protection of the eye is the most important issue to address in patients with facial nerve paralysis because corneal damage can result from increased surface exposure and disruption of the tear film. Management of facial nerve palsy depends on an individual's prognosis for recovery. Most patients will have spontaneous, complete recovery.
Facial nerve paralysis is estimated to affect 30 to 40 persons per 100,000 per year. The most common cause is Bell's palsy or idiopathic facial nerve palsy. Other causes include infection, as in Ramsay Hunt syndrome, neoplastic, as in parotid tumors and facial nerve schwannomas, and traumatic.
Protection of the eye is the most important issue to address in these patients because damage to the facial nerve can cause loss of innervation to the frontalis muscle. This results in brow ptosis and loss of innervation to the orbicularis oculi muscle, resulting in decreased voluntary and involuntary blink reflexes, lagophthalmos, as well as ectropion. Corneal damage can result from increased surface exposure and disruption of the tear film.
In the treatment of idiopathic facial nerve palsy, the use of steroids and acyclovir is controversial, and there is no consensus with regards to treatment dose, duration, or timing. Studies suggest that a cell-mediated immune response forms in response to the initial viral insult to the facial nerve. The virus thought to be most commonly involved is herpes simplex virus. A double-blind, placebo-controlled study by Adour et al. in 1996 comparing acyclovir/prednisolone with placebo and prednisolone treatment alone showed a significant improvement in facial paresis with acyclovir/prednisolone. However, in a more recent double-blind, placebo-controlled study by Sullivan et al. in 2007, 496 patients were randomly assigned to receive prednisolone, acyclovir, both agents, or placebo. The authors concluded that early treatment (within 72 hours) with prednisolone alone significantly improved the chances of recovery at 6 and 9 months. There was no benefit of acyclovir alone or in addition to prednisolone.