Bell’s Palsy


  • The most common cause of peripheral (the forehead is involved) facial paralysis
  • The cause is thought to be secondary to a viral infection usually herpes simplex virus or Lyme disease
  • Often treated with steroids. All cases show some recovery and if none is seen by 6 months another cause should be pursued
  • 80% recovery fully

Symptoms and Signs

  • Normally a viral illness precedes the onset of partial facial paralysis
  • Partial paralysis often progresses to complete paralysis within 1 week
  • Loss of taste and salivation (due to an affected chorda tympani)
  • Increased volume of sound (due to an affected stapedial branch of the facial nerve)
  • Decreased tearing of the eyes (due to an affected geniculate ganglion)


  • Incidence 200/1million people per year


  • Patients should seek prompt medical attention because of available treatment options
  • Based mostly on clinical exam demonstrating a facial paralysis with involvement of the forehead
  • Facial paralysis is graded using the House & Brackman grading scale
  • EMG and nerve conduction may be used


  • Steroids: Prednisone- reduce both the pain associated with Bell’s palsy and the number of patients with complete denervation.
  • Should be instituted promptly
  • Eye protection with artificial tears/ointment and avoiding bright light
  • Surgical decompression- very controversial and rarely used


  • Most cases demonstrate some improvement
  • 80% fully recover
  • 10% have partial recovery
  • 10% have a poor recovery

Differential Diagnosis

  • Other types of infection
  • Tumor
  • Trauma
  • Side effects of diabetes, fevers, or hypertension


  • Handbook of Neurosurgery: Greenberg
  • eMedicine