Basics
- 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)
Demographics
- Incidence 200/1million people per year
Diagnosis
- 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
- EMG and nerve conduction may be used
Treatment
- 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
Prognosis
- 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
References
- Handbook of Neurosurgery: Greenberg
- eMedicine
