Clinical Features

• Sensory disturbances

  • Painful sensation around or behind the ear [6]

  • Impairment of taste in the anterior tongue

  • Hyperacusis

• Dry mouth (as a result of decreased saliva production)

• Ocular features

  • Bell's phenomenon: a physiologic, reflexive movement of the eye (upward and outward) that occurs when the eyelid is actively closed

  • Lagophthalmos: The patient cannot fully close the eyes (due to paralysis of the orbicular oculi muscle). [7]

  • Decreased lacrimation

  • Corneal ulceration and keratitis

  • Ectropion

• Facial synkinesis: involuntary movements of the facial muscles (e.g., facial spasms while closing the eyes)

In central facial palsy, paralysis is contralateral to the lesion, and eyelid and forehead muscles are not affected!

Peripheral right facial nerve palsy

Mouth of a 53-year-old female showing drooping of the right corner of the mouth. The skin folds surrounding the mouth on the right side are no longer visible as a result of the absent muscle tone. When the patient is requested to grimace/show teeth, only the left side of the mouth reacts accordingly. Given her other clinical symptoms (taste disorder, impaired eyelid closure, inability to frown), peripheral facial nerve palsy (following mastoiditis) can be established as the diagnosis.

Impaired eyelid closure with visible eyelashes and Bell's phenomenon in left facial paralysis

Visible eyelashes (left image): Upon tight closure of the eyes, eyelashes remain visible on the affected side. This finding may indicate discrete facial palsy.

Bell's phenomenon (right image): The patient cannot properly and fully close the affected eye, i.e., lagophthalmos. This reveals the reflexive upward and outward movement of the eye when closing the eyes, showing the white sclera. This phenomenon is more evident in severe facial palsy.