cranial nerve VII palsy

Last reviewed 12/2022

  • a facial nerve palsy is paralysis of the facial nerve.
  • the facial nerve is the motor supply to the scalp, facial muscles and stapedius. It also supplies taste in the anterior 2/3 of the tongue via the chorda tympani branch.
  • the course of the facial nerve through the posterior fossa, temporal bone, and parotid gland makes it vulnerable to many neoplastic, traumatic, and infectious events (1)
  • a peripheral facial paralysis requires a complete head and neck examination including the following:
    • otoscopy
    • cranial nerve evaluation. (1)
  • the function of the facial nerve is tested as follows in the neurological examination:
    • brow:
      • the patient is asked to raise the eyebrows
      • the brow is spared in a unilateral upper motor neurone lesion - for example a stroke affecting one half of the face will spare the brow
      • if there is an upper motor neurone lesion affecting the facial nerve then the ability to wrinkle the brow is preserved; in Bell's palsy this ability is lost
    • eyes:
      • the patient is asked to screw up the eyes and resist attempts by the examiner to open the eyes
    • facial movement:
      • smiling, blowing out the cheeks, etc.

Reference: