title: Association between neurovascular contact on MRI and response to gamma knife radiosurgery in trigeminal neuralgia.
abstract: Treatment with gamma knife radiosurgery (GKRS) provides adequate short-term pain control in about 70% of the patients with intractable trigeminal neuralgia (TN). The purpose of our study was to evaluate whether the presence of neurovascular contact (NVC) at the root entry zone of the trigeminal nerve on pre-gamma knife MR imaging predicts an increased likelihood of an adequate response to GKRS. We studied 40 consecutive patients who underwent GKRS for treatment of intractable TN. Two neuroradiologists blinded to the side of symptoms analyzed pre-treatment constructive interference in steady state (CISS) images to determine the presence of NVC by consensus. An adequate response was defined as freedom from pain with or without reduced need for medical therapy. Adequate short-term response to GKRS was seen in 29 (72.5%) of 40 patients. NVC was seen in 30 of the 40 patients. Twenty-five (83.3%) of 30 patients with NVC had adequate short-term response to GKRS. Only four (40%) of the 10 patients without NVC had adequate response to GKRS (X2=7.06; P<0.01). Patients with NVC were seven times more likely to have an adequate response to GKRS than those without NVC (odds ratio =7.5).The presence of NVC on pre-treatment MR imaging predicts an increased likelihood of an adequate response to GKRS.
authors.affiliation: Department of Radiology, Tufts-New England Medical Center, 750 Washington St., Boston, MA 02111, USA. serbay@tufts-nemc.org
authors.forename: Sami H
authors.initials: SH
authors.lastname: Erbay
authors.forename: Rafeeque A
authors.initials: RA
authors.lastname: Bhadelia
authors.forename: Ron
authors.initials: R
authors.lastname: Riesenburger
authors.forename: Punita
authors.initials: P
authors.lastname: Gupta
authors.forename: Mark
authors.initials: M
authors.lastname: O'Callaghan
authors.forename: Eric
authors.initials: E
authors.lastname: Yun
authors.forename: Steven
authors.initials: S
authors.lastname: Oljeski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000295:instrumentation*; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000175:diagnosis* / Q000601:surgery*