title: Nerve atrophy in severe trigeminal neuralgia: noninvasive confirmation at MR imaging--initial experience.
abstract: OBJECTIVE
  To retrospectively evaluate the size of the trigeminal nerve on magnetic resonance (MR) images of patients with unilateral trigeminal neuralgia.
  
  
  METHODS
  Institutional review board approval was obtained and informed consent was waived for this HIPAA-compliant study. The sizes of the trigeminal nerves in 31 patients (18 men and 13 women; mean age, 68 years; age range, 44-84 years) with clinically confirmed intractable unilateral trigeminal neuralgia were measured before treatment with gamma knife radiosurgery. Images were analyzed separately by two neuroradiologists who were blinded to the side of the face with symptoms. Coronal projection images were used to determine the diameter and cross-sectional area of the trigeminal nerves at 5 mm from the entry point of the nerve into the pons. Comparisons were made by using a paired t test. Interobserver variability was assessed by using the Pearson correlation coefficient.
  
  
  RESULTS
  The mean diameter of the trigeminal nerve on the symptomatic side was significantly smaller than the mean diameter on the asymptomatic side in 30 of 31 patients (2.11 mm +/- 0.40 [standard deviation] and 2.62 mm +/- 0.56, P < .001, 95% confidence interval: -0.35, -0.67 mm). The mean cross-sectional area on the symptomatic side was significantly smaller than the area on the asymptomatic side in 27 of 31 patients (4.50 mm(2) +/- 1.75 and 6.28 mm(2) +/- 2.19, P < .001, 95% confidence interval: -2.41, -1.16 mm(2)).
  
  
  CONCLUSIONS
  The results indicate that trigeminal nerve atrophy can be depicted noninvasively in patients with trigeminal neuralgia.
authors.affiliation: Department of Radiology, Tufts-New England Medical Center, 750 Washington St, Boston, MA 02467, 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: Mark
authors.initials: M
authors.lastname: O'Callaghan
authors.forename: Punita
authors.initials: P
authors.lastname: Gupta
authors.forename: Ron
authors.initials: R
authors.lastname: Riesenburger
authors.forename: Warren
authors.initials: W
authors.lastname: Krackov
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Polak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014276:Trigeminal Nerve / Q000473:pathology*; D014277:Trigeminal Neuralgia / Q000473:pathology*