title: Reinnervation by the contralateral facial nerve in patients with peripheral facial palsy.
abstract: BACKGROUND
  Reinnervation activity is triggered after complete unilateral peripheral facial palsy (PFP).
  
  
  METHODS
  In 27 patients with PFP we recorded electromyographic activity with a concentric needle electrode inserted 1 cm lateral to the oral commissure of the affected side. We applied electrical stimuli to the unaffected (contralateral) facial nerve from the tragus to the mid-lower lip and measured the response latency variability and segmental conduction velocity.
  
  
  RESULTS
  Responses to electrical stimulation of the unaffected facial nerve were found in all patients. Mean conduction velocity was 49.6 ± 6.2 m/s between tragus and oral commissure, and 6.0 ± 1.9 m/s between oral commissure and mid-lower lip. Latency variability was 0.27 ms to facial nerve stimulation and 0.08 ms to oral commissure stimulation.
  
  
  CONCLUSIONS
  Short distance sprouting of axons that innervate muscle fibers, which originate from the unaffected facial nerve, results in propagation of impulses to muscle fibers in the midline.
authors.affiliation: Unitat d'EMG, Servei de Neurologia, Hospital Clínic, Barcelona 08036, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Casanova-Molla
authors.forename: Luci
authors.initials: L
authors.lastname: León
authors.forename: Carlos David
authors.initials: CD
authors.lastname: Castillo
authors.forename: Josep
authors.initials: J
authors.lastname: Valls-Solé
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D000368:Aged; D004558:Electric Stimulation / Q000379:methods; D005154:Facial Nerve / Q000502:physiology*; D005158:Facial Paralysis / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009416:Nerve Regeneration / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology