title: Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious-onset neck pain.
abstract: OBJECTIVE
  To investigate the presence of fatty infiltrate in the cervical extensor musculature in patients with insidious-onset neck pain to better understand the possible pathophysiology underlying such changes in chronic whiplash-associated disorders (WAD).
  
  
  METHODS
  A sample of convenience of 23 women with persistent insidious-onset neck pain (mean age 29.2+/-6.9 years) was recruited for the study. Magnetic resonance imaging (MRI) was used to quantify fatty infiltration in the cervical extensor musculature. Quantitative Sensory Testing (QST; pressure and thermal pain thresholds) was performed as sensory features are present in chronic whiplash. Self-reported pain and disability, as well as psychological distress, were measured using the Neck Disability Index (NDI) and the General Health Questionnaire-28 (GHQ-28), respectively.
  
  
  RESULTS
  Measures were compared with those of a previous dataset of chronic whiplash patients (n=79, mean age 29.7+/-7.8 years). Using a classification tree, insidious-onset neck pain was clearly identified from whiplash (p<0.001), based on the presence of MRI fatty infiltrate in the cervical extensor musculature (0/102 individuals) and altered temperature thresholds (cold; 3/102 individuals).
  
  
  CONCLUSIONS
  Fatty infiltrates in the cervical extensor musculature and widespread hyperalgesia were not features of the insidious-onset neck pain group in this study; whereas these features have been identified in patients with chronic WAD. This novel finding may enable a better understanding of the underlying pathophysiological processes in patients with chronic whiplash.
authors.affiliation: Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia. jelltt@regis.edu
authors.forename: J
authors.initials: J
authors.lastname: Elliott
authors.forename: M
authors.initials: M
authors.lastname: Sterling
authors.forename: J T
authors.initials: JT
authors.lastname: Noteboom
authors.forename: R
authors.initials: R
authors.lastname: Darnell
authors.forename: G
authors.initials: G
authors.lastname: Galloway
authors.forename: G
authors.initials: G
authors.lastname: Jull
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D002574:Cervical Vertebrae / Q000473:pathology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009334:Neck Muscles / Q000473:pathology*; D019547:Neck Pain / Q000150:complications / Q000473:pathology*; D017288:Pain Threshold; D013315:Stress, Psychological / Q000209:etiology; D014911:Whiplash Injuries / Q000150:complications / Q000473:pathology*