title: Trigeminal neuralgia: differences in magnetic resonance imaging characteristics of neurovascular compression between symptomatic and asymptomatic nerves.
abstract: OBJECTIVE
  Neurovascular compression (NVC) of the trigeminal nerve is the primary cause of trigeminal neuralgia (TN) but is known to occur in both symptomatic and asymptomatic nerves. The purposes of this study were to evaluate the relationship between the magnetic resonance imaging (MRI) findings regarding the site of NVC and the manifestation of TN symptoms.
  
  
  METHODS
  In 147 patients with unilateral TN, the presence or absence of NVC was evaluated on MRI in both symptomatic and asymptomatic nerves. In cases with NVC, the shortest distance from the trigeminal nerve root to the responsible vessel was measured.
  
  
  RESULTS
  The mean distance from the trigeminal nerve root to the site of NVC in asymptomatic nerves (3.85 ± 2.69 mm) was significantly greater than that in symptomatic nerves (0.94 ± 1.27 mm). When the distance was 3 mm or less, the rate of the manifestation of TN symptoms was 83.1% (103/124). On the other hand, it was only 19.6% (9/46) in cases with a distance of greater than 3 mm.
  
  
  CONCLUSIONS
  Whether or not NVC of the trigeminal nerve was symptomatic was closely related to the distance from the trigeminal nerve root to the responsible blood vessel.
authors.affiliation: Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Madoka
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University. Electronic address: norio.orad@tmd.ac.jp.
authors.forename: Norio
authors.initials: N
authors.lastname: Yoshino
authors.affiliation: Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Akemi
authors.initials: A
authors.lastname: Tetsumura
authors.affiliation: Department of Anesthesiology and Clinical Physiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Tomoka
authors.initials: T
authors.lastname: Matsumura
authors.affiliation: Department of Anesthesiology and Clinical Physiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Fukayama
authors.affiliation: Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University.
authors.forename: Tohru
authors.initials: T
authors.lastname: Kurabayashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000150:complications*; D012189:Retrospective Studies; D014277:Trigeminal Neuralgia / Q000209:etiology*