title: Cervical muscle area measurements in acute whiplash patients and controls.
abstract: OBJECTIVE
  To quantitatively compare the muscle cross-sectional areas (CSAs) of the cervical muscles in symptomatic acute whiplash patients versus healthy controls. We hypothesized, that symptomatic whiplash patients have smaller cervical muscle CSAs than matched controls and that smaller cervical muscle CSAs in women might explain that women more frequently are symptomatic after whiplash injury than men.
  
  
  METHODS
  Prospective controlled study. Thirty-eight consecutive acute whiplash patients were examined within 48 h after a motor vehicle accident and 38 healthy age- and sex-matched controls, each half female, half male, were examined with the same protocol. MRI CSA measurements were performed of the deep and total cervical extensor muscles as well as the sternocleidomastoid muscles using transversal STIR (Short T1 Inversion Recovery) sequences on level C2, C4, and C5 by two blinded raters. Clinical symptoms were assessed with patient questionnaires (EuroQuol 5D, Specific Whiplash Questionnaire, head- and neck pain intensity [VAS]).
  
  
  RESULTS
  Agreement of measurements between the two raters was high (intraclass correlation 0.52 to 0.85 for the different levels). No significant difference in age and body mass index were seen between patients and controls and the distribution of genders across groups was identical. There were no significant differences between patients and controls for all CSAs. Women had consistently smaller CSAs than men. The CSAs showed no significant correlation with the pain intensity of neck pain and headache but a consistent tendency of less neck pain and more headache with greater CSAs.
  
  
  CONCLUSIONS
  This small study provides no evidence that subjects with smaller CSAs of cervical extensor muscles have a higher risk in developing symptoms after a whiplash injury and confirms smaller CSA in women.
authors.affiliation: Department of Radiology, Orthopedic University Hospital Balgrist, Zürich, Switzerland. erikajulbrich@googlemail.com
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Ulbrich
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Anderson
authors.forename: Andre
authors.initials: A
authors.lastname: Busato
authors.forename: Susanne
authors.initials: S
authors.lastname: Abderhalden
authors.forename: Chris
authors.initials: C
authors.lastname: Boesch
authors.forename: Heinz
authors.initials: H
authors.lastname: Zimmermann
authors.forename: Paul
authors.initials: P
authors.lastname: Heini
authors.forename: Juerg
authors.initials: J
authors.lastname: Hodler
authors.forename: Matthias
authors.initials: M
authors.lastname: Sturzenegger
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015233:Models, Statistical; D009132:Muscles / Q000473:pathology; D010146:Pain; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014911:Whiplash Injuries / Q000175:diagnosis*