title: Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography.
abstract: BACKGROUND
  We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies.
  
  
  METHODS
  The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale.
  
  
  RESULTS
  Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome.
  
  
  CONCLUSIONS
  In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance.
authors.affiliation: Spine Section, Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan. masashiy@faculty.chiba-u.jp
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okawa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Atsuomi
authors.initials: A
authors.lastname: Aiba
authors.forename: Yukio
authors.initials: Y
authors.lastname: Someya
authors.forename: Masao
authors.initials: M
authors.lastname: Koda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001268:Atlanto-Axial Joint; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004314:Down Syndrome / Q000150:complications* / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D015994:Incidence; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013123:Spinal Fusion; D014057:Tomography, X-Ray Computed; D014711:Vertebral Artery / Q000002:abnormalities*