Bell’s Palsy

Table of Contents

  1. Disorder
  2. Epidemiology
  3. Pathophysiology
  4. Risk Factors & Associations
  5. Signs & Symptoms
  6. Diagnostic Criteria
  7. Diagnostic Workup
  8. Disease Modifying Therapy (DMT)
  9. Non-DMT Treatment
  10. Followup
  11. Scales
  12. Prognosis
  13. References

- 40-60mg/g of prednisone (or equivalent glucocorticoid) for 7 to 10 days (thought to decrease swelling of the nerve in the small facial canal to reduce the possibility of permanent paralysis

- Unclear, however postulated to be due to a viral infection of the nerve, most notably herpes simplex virus

Pathophysiology

Risk factors & Associations

- Possibly more common in diabetic or hypertensive patients and women in their 3rd trimester of pregnancy

Signs & Symptoms

Diagnostic Criteria

Diagnostic Workup

- Incidence: 23/100000
- F:M Ratio: 1:1

Management

- Acute (not hyperacute), with maximal facial paralysis around 2-4 days
- Pain behind the ear may precede the paralysis by 1-2 days
- Fullness or numbness in the face with a small subset having hypesthesia in one or more branches of the trigeminal nerve (pathophysiology of this is unclear but postulated to be cross fibers of the sensory fibers with the fibers of the facial nerve during development)
- Impaired taste sensation in the anterior 2/3 of the tongue on the ipsilateral side of paralysis
- Hyperacusis due to paralysis of the stapedius muscle

Disorder

Acute unilateral facial nerve dysfunction of unknown etiology

Epidemiology

Differential Diagnosis

- Lyme

- HIV

- Sarcoidosis

Followup

Prognosis

References

  1. Hauser WA, Karnes WE, Annis J, Kurland LT: Incidence and prognosis of Bell’s Palsy in the population of Rochester, Minnesota. Mayo Clin Proc 46:258, 1971

  2. Baringer JH: Herpes simplex virus and Bell’s Palsy. Ann Intern Med 124:63, 1996

- 70% recover within a month, 85% recover completely
- Bad prognostic signs: Pronounced contrast enhancement in the nerve on MRI
- Good prognostic signs:  Return of taste sensation within the first week. Motor recovery within 5-7 days is the best sign of a good prognosis
- Recurrence: Up to 8% of patients, presumably from reactivation of latent herpes simplex virus
- Followup for re-examination in 4-6 months with PCP and or neurology
  • If persistent facial palsy present or involvement of additional cranial nerves/new focal neurologic deficits, MRI Brain w/wo contrast should be pursued, +/- LP depending on new differential diagnosis