Bell's palsy

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Background

  • Dysfunction of peripheral cranial nerve 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

Clinical Features

Right-sided peripheral facial nerve palsy with inability to wrinkle the forehead and nose, unequal lid fissures, and inability to lift the corner of the mouth.
  • Acute onset (over hours) of unilateral facial paralysis
    • No forehead sparing
  • Inability to raise eyebrows
  • Drooping of angle of the mouth
  • Incomplete closure of the eyelids on the affected side
    • Can lead to corneal exposure keratitis

Associated Symptoms

  • Alterations in taste
  • Hyperacusis
  • Inability to produce tears
  • Subjective feeling of facial numbness without objective findings

Differential Diagnosis

Facial paralysis

Others

Evaluation

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

Management

  • Cornea eye protection (Level X)[2]
    • Artificial tears qhr while patient is awake
    • Ophthalmic ointment at night
    • Eye should be taped shut at night
    • Protective glasses or goggles

Steroids

Should be started within 72hrs of symptom onset[3]

Antivirals

Most likely no added benefit when combined with steroids.[6] However also little harm associated with antivirals especially in patients with normal renal function[5]

Disposition

  • Discharge with ophtho follow up 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.

Prognosis

  • Most patients recover completely, although some have permament disfiguring facial weakness[7]
    • 71% of untreated patients recover completely
    • An additional 13% of untreated patients achieve near-normal function (a total of 84% achieve normal or near-normal function even without treatment)

Poor Prognostic Indicators

Any one of the following[8]

  • Older age
  • Hypertension
  • Impairment of taste
  • Pain other than in the ear
  • Complete facial weakness

See Also

References

  1. Greco A. et al. Bell's palsy and autoimmunity. Autoimmun Rev. 2012;12 622-627
  2. 2.0 2.1 2.2 Baugh RF, et al. Clinical practice guideline: Bell's palsy. Otolaryngol Head Neck Surg. 2013 Nov;149(3 Suppl):S1-S27.
  3. Vargish L. For Bell’s palsy, start steroids early; no need for an antiviral. J Fam Pract. Jan 2008; 57(1): 22–25http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3183838/pdf/JFP-57-22.pdf
  4. 4.0 4.1 UpToDate. Bell's Palsy Prognosis and Treatment. March, 2014
  5. 5.0 5.1 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
  6. Lockhart et al. Cochrane Database Syst Rev. 2009 Oct 7;(4):CD001869.
  7. Peitersen E. The natrual history of Bell's palsy. Am J Otol 1982;4:107-111.
  8. Gilden. Bell's Palsy. N Engl J Med 2004; 351:1323-1331