Electroneurographic facial muscle pattern in Bell's palsy

To study the electroneurographic facial muscle pattern in Bell's palsy over time, electroneurographic recordings in the frontalis, orbicularis oculi, nasalis, and mentalis muscle regions were performed early (mean, day 11) an d 1 and 3 months after the onset of the condition in 30 consecutive patient s. The correlation between facial muscle electroneurographic recordings ove r time was also calculated. An additional aim was to assess whether further prognostic information could be obtained by electroneurographic recordings in more than one facial region. The recovery pattern was similar in all 4 facial regions. Initially, the correlation between the facial recordings wa s weak (r = 0.20-0.27), but it was improved at follow-up examinations (r = 0.33-0.65). Favorable outcome in 23 of 24 patients (96%) could have been pr edicted by the initial nasalis and/or mentalis recordings. The gap between patients with favorable outcome and patients with unfavorable outcome incre ased when the average electroneurography values were calculated from 1, 2, and 4 muscle recordings (4%, 8%, and 15%, respectively). Our results indica te that in Bell's palsy, electroneurographic examination of more than one f acial muscle region may add prognostic information and that the degree of d egeneration is initially different in the nerve branches.