Facial Palsy: A Retrospective Study of 416 Cases Based on Electrodiagnostic Consultation

Abstract

<jats:sec> <jats:title>Background:</jats:title> <jats:p>Facial nerve palsy (FP) is a frequent neurological condition caused mostly by Bell´s Palsy (BP).</jats:p> </jats:sec> <jats:sec> <jats:title>Objectives:</jats:title> <jats:p>The main objective of this study is to describe electrophysiological parameters in a retrospective 28-year review of 416 cases of FP based on electrodiagnostic consultation.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>In total, 520 exams from 416 patients over a 28-year period were reviewed. Sex, age, etiology, comorbidities, and variables from electroneurography and needle electromyography were analyzed. Cases were grouped as BP (70.7%), injury (16.4%), iatrogenic (10.3%) and Ramsay Hunt syndrome (RHS) (2.6%).</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>The mean age was 41 years (3-82), 53.4% female. Diabetes was the most frequent comorbidity. Estimated Axon Loss (EAL), &gt;90%, was found in 50% of the cases, mainly in the iatrogenic group. The amplitude drop of the Compound Muscle Action Potentials (CMAPs) was proportional in the <jats:italic>Orbicularis Oculi</jats:italic>, <jats:italic>Orbicularis Oris</jats:italic> and <jats:italic>Nasalis</jats:italic> muscles. The absence of CMAPs was more frequent in the iatrogenic group and less frequent in the BP one. Bell´s palsy associated with diabetes was more severe. The R1 latency (blink reflex) was significantly longer in the BP group (P&gt;0.001). Synkinesis due to the misdirection of regenerating axons was much more frequent in the BP and RHS groups.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion:</jats:title> <jats:p>Bell´s palsy was the most common cause. The EAL was equal in all facial branches. Facial nerve inexcitability was more frequent in the iatrogenic/injury groups. The R1 latency was found to be prolonged in the BP group and the only good prognosis indicator in a few cases. Misdirection reinnervation was more frequent in BP and RHS groups. There was no sex or side predominance.</jats:p> </jats:sec>