• Bell Palsy is the most common cause of unilateral facial weakness.

• It is caused by edema and ischemia causing compression of the facial nerve (cranial nerve seven).

• While Bell Palsy is by definition an idiopathic facial palsy, the etiology is often infact discovered and attributed to conditions such as Lyme Disease, Herpes Simplex Virus, and HIV.

• Classic symptoms of Bell Palsy include:

          -- acute onset of unilateral upper and lower facial paralysis (over 48 hr. period)

          -- posterior auricular pain

          -- decreased tearing

          -- hyperacusis (due to stapedius muscle weakness)

          -- taste disturbances

• Bell Palsy is a diagnosis of exclusion.  If the facial paralysis is isolated to the lower face, if there is associated contralateral weakness, and/or if there is diplopia, a central cause for the symptoms, rather than Bell Palsy, must be strongly considered.