title: Duplex Ultrasonography-Detected Positional Vertebral Artery Occlusion in Upper Cervical Rheumatoid Arthritis.
abstract: METHODS
  Prospective imaging study.
  
  
  OBJECTIVE
  To clarify the frequency of positional vertebral artery (VA) occlusion using duplex ultrasonography in patients with rheumatoid arthritis (RA).
  
  
  BACKGROUND
  Some patients with upper cervical RA develop thromboembolic stroke related to positional and transient VA occlusions; however, whether RA patients have positional VA occlusion without neurological symptoms is unclear.
  
  
  METHODS
  Outpatients with RA were enrolled. Clinical data were collected, and radiograph examinations were performed to measure the anterior atlantodental interval (AADI), the posterior atlantodental interval (PADI), and the Ranawat method. Patients underwent duplex ultrasonography during rotation to the contralateral side of the examination side, flexion, and extension of their neck. If positional VA occlusion was detected, CT angiography was conducted in the neutral position and in the same position that showed VA occlusion on duplex ultrasonography. Clinical and radiological data were compared between the VA occlusion (VAO) group and the non-VAO group. Sensitivity-specificity curve analyses were performed to clarify optimal threshold values of AADI, PADI, and the Ranawat method for predicting positional VA occlusion.
  
  
  RESULTS
  Of the 132 RA patients, dynamic duplex ultrasonography showed positional VA occlusion in eight (6%) patients. Patients in the VAO group had a greater AADI (median, 7.4 vs. 2.3 mm; P < 0.001), a shorter PADI (median, 13.7 vs. 19.6 mm; P = 0.002), and a lower Ranawat value (median, 13.7 vs. 16.8 mm; P = 0.006) than those in the non-VAO group. Cut-off values of AADI, PADI, and the Ranawat method for predicting positional VA occlusion were 6.5, 14.0, and 15.5 mm, respectively.
  
  
  CONCLUSIONS
  A subset of RA patients developed positional VA occlusion associated with cervical spine involvement.
authors.affiliation: *Cerebrovascular Center, Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki, Japan †Department of Orthopedic Surgery, Nagasaki University Hospital, Nagasaki, Japan ‡First Department of Internal Medicine, Nagasaki University Hospital, Nagasaki, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Tateishi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tagami
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.forename: Tsujino
authors.initials: T
authors.lastname: Akira
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000000981:diagnostic imaging*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014463:Ultrasonography; D014711:Vertebral Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology