Electrodiagnostic testing in acute facial palsy: Outcomes and comparison of methods

Nicholas S. Andresen, Vivian Zhu, Andrew Lee, Wendy Sebetka, Jun Kimura, Marlan R. Hansen, Bruce J. Gantz, Daniel Q. Sun

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Objective: To study the relationship between various electrodiagnostic modalities in acute facial palsy. Setting: Academic tertiary care center. Patients: One-hundred and six patients who presented with traumatic or non-traumatic acute facial paralysis (House-Brackmann, HB, grade 6/6) between 2008 and 2017 and underwent acute electrodiagnostic testing. Intervention: Electroneurography (ENoG) using nasolabial fold (NLF) or nasalis muscle (NM) methods, and volitional electromyography (EMG) in all patients. Main outcome measures: Percent degeneration of ipsilateral facial nerve compound muscle action potentials (CMAP) on NLF- and NM-ENoG, presence or absence of muscle unit potentials (MUPs) on EMG. Results: Extent of facial nerve degeneration measured by NLF- and NM-ENoG were highly correlated (r = 0.85, P <.01) on each test and on serial testing. NLF- and NM-ENoG concordantly diagnosed ≥90% degeneration in 44 patients (80%), of whom 32 patients were diagnosed to have 100% degeneration by both methodologies. Absence of MUPs on EMG was 63% sensitive and 92% specific for ≥90% degeneration on ENoG, with a positive predictive value of 90%. For patients with Bell's palsy, percent degeneration on ENoG was also correlated to HB score at 1 year. Surgical decompression resulted in mean HB scores of 2.2 and 3.0 for patients with Bell's palsy and trauma, respectively. Conclusions: NM-ENoG may be a valid and comparable method to NLF-ENoG for predicting the recovery of facial nerve function in acute paralysis. Absence of MUPs on EMG is a specific measure of severe degeneration and highly predictive of candidacy for surgical decompression. Level of evidence: Level 3.

Original languageEnglish (US)
Pages (from-to)928-935
Number of pages8
JournalLaryngoscope investigative otolaryngology
Issue number5
StatePublished - Oct 1 2020
Externally publishedYes


  • Bell's palsy
  • electrodiagnostic testing
  • electroneurography
  • facial nerve decompression
  • facial paralysis
  • herpes zoster
  • temporal bone fracture

ASJC Scopus subject areas

  • Surgery
  • Otorhinolaryngology


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