title: Thoracic discography in healthy individuals. A controlled prospective study of magnetic resonance imaging and discography in asymptomatic and symptomatic individuals.
abstract: METHODS
  A prospective case-control investigation.
  
  
  OBJECTIVE
  To determine the responses to thoracic discography of asymptomatic individuals.
  
  
  BACKGROUND
  Literature regarding lumbar and cervical discography reveals that even morphologically abnormal discs often are not painful, whereas painful discs typically exhibit anular or endplate disruption.
  
  
  METHODS
  Ten adult lifelong asymptomatic volunteers, ages 23 to 45 years, underwent magnetic resonance imaging of the thoracic spine, followed by four-level discography. Provocative responses were graded on a scale of 0 (no sensation) to 10 (extreme pain or pressure), and filmed discs were graded using a modified Dallas scheme. Concomitantly, 10 nonlitigious adults (6 men and 4 women, ages 31 to 55 years) experiencing chronic thoracic pain were similarly studied as a control group.
  
  
  RESULTS
  The mean pain response in the asymptomatic volunteers was 2.4/10. Three discs were intensely painful (scores of 7/10, 8/10, 10/10), with all three exhibiting prominent endplate irregularities and anular tears typical of thoracolumbar Scheuermann's disease. On discography, 27 of 40 discs were abnormal, with endplate irregularities, anular tears, and/or herniations. Ten discs read as normal on magnetic resonance imaging showed anular pathology on discography. In the group with chronic thoracic pain, the average pain response was 6.3/10 (P < 0.05). Of the 48 discs studied, 24 were concordantly painful, with a pain response of 8.5/10 (P < 0.05); 17 had nonconcordant pain/pressure, with an average pain of 4.8/10 (P < 0.05); and 5 had no response. On magnetic resonance imaging 21 of the 48 discs appeared normal. However, on discography, only 10 were judged as normal.
  
  
  CONCLUSIONS
  On discography, thoracic discs with prominent Schmorl's nodes may be intensely painful, even in lifelong asymptomatic individuals, but the pain is unfamiliar or nonconcordant. Thoracic discography may-demonstrate disc pathology not seen on magnetic resonance imaging.
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, USA.
authors.forename: K B
authors.initials: KB
authors.lastname: Wood
authors.forename: K P
authors.initials: KP
authors.lastname: Schellhas
authors.forename: T A
authors.initials: TA
authors.lastname: Garvey
authors.forename: D
authors.initials: D
authors.lastname: Aeppli
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D007405:Intervertebral Disc Displacement / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013904:Thoracic Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging