Which nerve conductions findings have prognostic significance in Bell palsy (idiopathic facial paralysis) (IFP)?

Updated: Jun 14, 2019
  • Author: Danette C Taylor, DO, MS, FACN; Chief Editor: Selim R Benbadis, MD  more...
  • Print
Answer

Comparison to the contralateral side helps to demonstrate the extent of nerve injury and has prognostic implications. Nerve conduction responses are abnormal if a difference of 50% in amplitude between the paralyzed and normal side is detected; a difference of 90% between the 2 sides suggests a poorer prognosis.

May et al demonstrated that prognosis may be favorable if the motor amplitude of the affected side is greater than 25% of that of the normal side. An incomplete recovery was observed in patients whose results demonstrated less than 25% amplitude on the paralyzed side. [41] Blink reflexes can be used to measure conduction across the involved segment, but they are commonly absent in Bell palsy.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!