title: Stereotactic gamma knife surgery for trigeminal neuralgia: detailed analysis of treatment response.
abstract: OBJECTIVE
  The purpose of this study was to assess the durability and completeness of pain relief in patients treated using stereotactic gamma knife surgery (GKS) for trigeminal neuralgia (TN).
  
  
  METHODS
  Thirty-eight patients with refractory TN were treated with stereotactic GKS. All patients received a prescription radiation dose of 35, 40, or 45 Gy to the 50% isodose surface through a 4-mm collimator helmet. The group was assessed regularly based on physician-directed interviews for a median follow up of 24 months (range 6-27 months). Pain relief was classified as excellent (no pain without medication), good (well-controlled pain with continued medication), fair (decreased but residual pain with continued medication), or poor (unimproved or increased pain with the same or increased medication). Three months after treatment, pain relief was good or excellent in 71% of patients. By 24 months post-GKS, 50% of the original cohort had poor pain relief, 21% continued to have either excellent or good relief, 3% had fair relief, and 26% had not reached the 24-month follow up. Based on their status at the last follow up, 29% of patients had excellent and 16% had good pain relief. Thirty-seven percent experienced facial numbness, which was dose related. In addition, there was a significantly higher rate of complete pain relief in patients who had facial numbness following treatment (p = 0.003).
  
  
  CONCLUSIONS
  Stereotactic GKS is an effective treatment in patients with TN; however, the durability of pain relief and the time to treatment response are limiting factors. As with other types of ablative treatment, facial numbness is strongly associated with better treatment response.
authors.affiliation: Department of Neurosurgery, Roswell Park Cancer Institute and State University of New York School of Medicine and Biomedical Sciences, Buffalo, New York 14263, USA.
authors.forename: Rabih G
authors.initials: RG
authors.lastname: Tawk
authors.forename: Mary
authors.initials: M
authors.lastname: Duffy-Fronckowiak
authors.forename: Bryan E
authors.initials: BE
authors.lastname: Scott
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Alberico
authors.forename: Aidnag Z
authors.initials: AZ
authors.lastname: Diaz
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Podgorsak
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Plunkett
authors.forename: Robert A
authors.initials: RA
authors.lastname: Fenstermaker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology; D016634:Radiosurgery / Q000379:methods; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000503:physiopathology / Q000601:surgery*