title: A case-control study of cerebellar tonsillar ectopia (Chiari) and head/neck trauma (whiplash).
abstract: OBJECTIVE
  Chiari malformation is defined as herniation of the cerebellar tonsils through the foramen magnum, also known as cerebellar tonsillar ectopia (CTE). CTE may become symptomatic following whiplash trauma. The purpose of the present study was to assess the frequency of CTE in traumatic vs non-traumatic populations.
  
  
  METHODS
  Case-control.
  
  
  METHODS
  Cervical MRI scans for 1200 neck pain patients were reviewed; 600 trauma (cases) and 600 non-trauma (controls). Half of the groups were scanned in a recumbent position and half were scanned in an upright position. Two radiologists interpreted the scans for the level of the cerebellar tonsils.
  
  
  RESULTS
  A total of 1195 of 1200 scans were read. CTE was found in 5.7% and 5.3% in the recumbent and upright non-trauma groups vs 9.8% and 23.3% in the recumbent and upright trauma groups (p = 0.0001).
  
  
  CONCLUSIONS
  The results described in the present investigation are first to demonstrate a neuroradiographic difference between neck pain patients with and without a recent history of whiplash trauma. The results of prior research on psychosocial causes of chronic pain following whiplash are likely confounded because of a failure to account for a possible neuropathologic basis for the symptoms.
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health and Science University School of Medicine, Portland, OR 97205, USA. forensictrauma@gmail.com
authors.forename: Michael D
authors.initials: MD
authors.lastname: Freeman
authors.forename: Scott
authors.initials: S
authors.lastname: Rosa
authors.forename: David
authors.initials: D
authors.lastname: Harshfield
authors.forename: Francis
authors.initials: F
authors.lastname: Smith
authors.forename: Robert
authors.initials: R
authors.lastname: Bennett
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Centeno
authors.forename: Ezriel
authors.initials: E
authors.lastname: Kornel
authors.forename: Ake
authors.initials: A
authors.lastname: Nystrom
authors.forename: Dan
authors.initials: D
authors.lastname: Heffez
authors.forename: Sean S
authors.initials: SS
authors.lastname: Kohles
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000175:diagnosis*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis* / Q000209:etiology; D056888:Patient Positioning; D014911:Whiplash Injuries / Q000150:complications / Q000175:diagnosis*