Bell's palsy

Revision as of 16:30, 18 October 2014 by Ostermayer (talk | contribs) (Antivirals)


  • Dysfunction of peripheral CN VII of unknown cause due to Inflammation at geniculate ganglion [1]
  • Maximal clinical weakness around 3wks; at least partial recovery by 6 months
  • Always test CN VI function (should be normal) to rule-out CVA

Differential Diagnosis

  1. Amyloidosis
  2. Anesthesia nerve blocks
    1. Cerebral Aneurysms (vertebral, basilar, or carotid)
  3. Botulism
  4. CVA
  5. Guillain-Barré Syndrome
  6. HIV
  7. Intracranial Hemorrhage
  8. Lyme Disease
  9. Malignant Otitis Externa
  10. Meningitis
  11. Neurosyphilis
  12. Otitis Media (acute or chronic)
  13. Parotitis
  14. Ramsay Hunt syndrome
  15. Sarcoidosis
  16. Tumor
    1. Acoustic neuroma or other cerebellopontine angle lesions
    2. Meningioma
    3. Cerebellar pontine angle
    4. Facial nerve schwannomaa
    5. Parotid
    6. Sarcoma

Work Up

  • Clinicians should NOT obtain routine laboratory testing or diagnostic imaging in patients with new-onset Bell's palsy (Level C)[2]

Clinical Features

  • Acute onset (over hours) of unilateral facial paralysis
    • No forehead sparing
  • Inability to raise eyebrows
    • Drooping of angle of the mout
  • Incomplete closure of the eyelids on the affected side
    • Can lead to corneal exposure keratitis

Associated Symptoms

  1. Alterations in Taste
  2. Hyperacusis
  3. Inability to produce tears
  4. Subjective feeling of facial numbness although no demonstrable numbness


  1. Cornea eye protection (Level X)[2]
    1. Artificial tears qhr while pt is awake AND
    2. Ophthalmic ointment at night
    3. Protective glasses or goggles


  1. Prednisone 60-80mg qday x1wk[3] (Level B Evidence)[4]
    • Steroids should be started within 72hrs of symptoms[5]


  • Most likely no added benefit when combined with steroids. However also little harm associated with antivirals especially in patients with normal renal function
  1. Valacyclovir 1000mg TID x1wk[3] OR
  2. Acyclovir 400mg 5x per day x 1wk


  • Discharge with ophtho f/u for monitoring of the affected cornea
  • Refer to a facial nerve specialist for:[2]
    • New or worsening neurologic findings at any point
    • Ocular symptoms developing at any point
    • Incomplete facial recovery 3 months after initial symptom onset.

See Also


  • Tintinalli


  1. Greco A. et al. Bell's palsy and autoimmunity. Autoimmun Rev. 2012;12 622-627
  2. 2.0 2.1 2.2 2.3 Baugh RF, et al. Clinical practice guideline: Bell's palsy. Otolaryngol Head Neck Surg. 2013 Nov;149(3 Suppl):S1-S27.
  3. 3.0 3.1 UpToDate. Bell's Palsy Prognosis and Treatment. March, 2014
  4. Gronseth GS, Paduga R. Evidence-based guideline update: Steroids and antivirals for Bell palsy: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology. 2012Full Text
  5. Vargish L. For Bell’s palsy, start steroids early; no need for an antiviral. J Fam Pract. Jan 2008; 57(1): 22–25