Clinical features

• characteristics of a peripheral facial paralysis ( seen on the affected side) include: (1)
  • unable to wrinkle forehead
  • unable to raise eyebrow
  • unable to wrinkle nasolabial fold
  • unable to purse lips or show teeth
  • inability to completely close eye
  • lacrimation, salivation and taste is likely to be impaired when the lesion is proximal or involving the geniculate ganglion (2)
  • when the lesion is distal to the internal auditory canal and geniculate ganglion lacrimation is intact but, salivation and taste is likely to be impaired (2)
  • decreased taste - indicates a lesion above origin of the chorda tympani
  • hyperacusis -indicates the lesion is above nerve to stapedius
  • reduction of lacrimation - indicates the lesion is above the geniculate ganglion
  • Bell phenomenon
    • on closing the affected eye there is visible vertical rotation of the globe
• characteristics of a central facial paralysis include: (1)
  • movements of the frontal and upper orbicularis oculi muscles tend to be spared since there are uncrossed contributions from ipsilateral supranuclear areas
  • during emotional expression facial movement may be present on affected side
  • lacrimation, taste, and salivation is intact (2)

Reference:

• (1) Facial Paralysis, Medical Content of Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery,Baylor College of Medicine, ©2006
• (2) Gilden DH, Bell's Palsy,Table 2, Clinical and Anatomical Features of Facial-Nerve Damage, N Engl J Med, September 23, 2004  351:1323