title: Identifying the trigeminal nerve branches for transovale radiofrequency thermolesion:  "no pain, no stress".
abstract: BACKGROUND
  Radiofrequency thermorhizotomy of the trigeminal nerve is a known treatment of trigeminal neuralgia. Analysis of verbal responses to electric stimulation of the trigeminal rootlets has been the only method available to localize the affected branch, but patient discomfort may lead to unreliable verbal responses, resulting in increased morbidity or even therapeutic failure. Orthodromically elicited evoked potentials of the trigeminal nerve have also been used, but their application is tedious and results may vary.
  
  
  OBJECTIVE
  To develop an electrophysiological method for intraoperative localization of the trigeminal nerve branches.
  
  
  METHODS
  A series of 55 patients under general anesthesia during radiofrequency thermorhizotomy were studied. The trigeminal nerve root was stimulated through the foramen ovale with the RF electrode. Antidromic responses were recorded from the 3 divisions of the trigeminal nerve in the face. Effectiveness rate, pain relief, recurrence, complications, and patient comfort after the procedure were analyzed.
  
  
  RESULTS
  Reproducible and easily obtained antidromic responses were clearly recorded in every subdivision of the trigeminal nerve in all patients. Ninety-four percent of patients experienced immediate pain relief after the procedure. The recurrence rate was 12.72%, and the surgical morbidity was 20%.
  
  
  CONCLUSIONS
  This method proved to be useful to determine the exact localization of individual subdivisions of the trigeminal nerve in anesthetized patients, making this procedure safer and more comfortable for them.
authors.affiliation: Intraoperative Neurophysiology Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. mariana.bendersky@hospitalitaliano.org.ar
authors.forename: Mariana
authors.initials: M
authors.lastname: Bendersky
authors.forename: Santiago
authors.initials: S
authors.lastname: Hem
authors.forename: Federico
authors.initials: F
authors.lastname: Landriel
authors.forename: Javier
authors.initials: J
authors.lastname: Muntadas
authors.forename: Martín
authors.initials: M
authors.lastname: Kitroser
authors.forename: Carlos
authors.initials: C
authors.lastname: Ciralo
authors.forename: Guillermo
authors.initials: G
authors.lastname: Agosta
mesh_terms: D000368:Aged; D017115:Catheter Ablation / Q000379:methods* / Q000523:psychology; D004558:Electric Stimulation / Q000379:methods; D004568:Electrodiagnosis / Q000379:methods / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods* / Q000523:psychology; D019051:Rhizotomy / Q000379:methods; D013315:Stress, Psychological / Q000517:prevention & control; D014277:Trigeminal Neuralgia / Q000517:prevention & control / Q000523:psychology* / Q000601:surgery*