title: Trigeminal neuralgia related to megadolichobasilar artery compression: a prospective series of twenty-nine patients treated with gamma knife surgery, with more than one year of follow-up.
abstract: BACKGROUND
  Trigeminal neuralgia (TN) secondary to megadolichobasilar artery (MBA) compression is considerably difficult to manage surgically.
  
  
  OBJECTIVE
  This study aims to evaluate the safety/efficacy of Gamma Knife surgery (GKS) in this special group of patients.
  
  
  METHODS
  Between July 1992 and November 2010, 29 patients with >1 year of follow-up presenting with MBA compression were treated with GKS at Timone University Hospital. Radiosurgery was performed using a Gamma Knife (model B, C or Perfexion). A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 9.1 mm (range: 6-18.2 mm) from the emergence.
  
  
  RESULTS
  The median follow-up period was 46.1 months (range: 12.9-157.9 months). Initially, all patients (100%) were pain free; the average time to complete pain relief was 13.5 days (range: 0-240 days). Their actuarial probability of remaining pain free without medication at 0.5, 1 and 2 years was 93.1, 79.3 and 75.7%, respectively, and remained stable until 13 years after treatment. The actuarial probability of hypoesthesia onset at 6 months was 4.3%; at 1 year it reached 13% and remained stable until 13 years after treatment.
  
  
  CONCLUSIONS
  GKS proved to be reasonably safe and effective on a long-term basis as a first- and/or second-line surgical treatment for TN due to MBA compression.
authors.affiliation: Functional and Stereotactic Neurosurgery Unit, INSERM U751, Centre Hospitalier Universitaire La Timone Assistance Publique-Hôpitaux de Marseille, Marseille, France.
authors.forename: Constantin
authors.initials: C
authors.lastname: Tuleasca
authors.forename: Romain
authors.initials: R
authors.lastname: Carron
authors.forename: Noémie
authors.initials: N
authors.lastname: Resseguier
authors.forename: Anne
authors.initials: A
authors.lastname: Donnet
authors.forename: Philippe
authors.initials: P
authors.lastname: Roussel
authors.forename: Jean
authors.initials: J
authors.lastname: Gaudart
authors.forename: Marc
authors.initials: M
authors.lastname: Levivier
authors.forename: Jean
authors.initials: J
authors.lastname: Régis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001488:Basilar Artery / Q000473:pathology* / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods / Q000639:trends*; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery*