title: [Natural history and prognosis of discogenic low back pain].
abstract: OBJECTIVE
  To understand the natural history and prognosis of patients with discogenic low back pain so as to offer a better guide on its clinical treatment.
  
  
  METHODS
  From December 2003 to November 2004, we consecutively hospitalized 72 patients with discogenic low back pain diagnosed by lumbar discography. These patients were randomized into two groups. One group (n = 36) received an intradiscal methylene blue (MB) injection immediately after discography while another group (n = 36) received a placebo. Both Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were used to assess the back pain symptoms and the lumbar function respectively during a 4-year follow-up period.
  
  
  RESULTS
  In total, 32 of 36 patients who received a placebo injection underwent a 4-year follow-up. Of these patients, 4 cases (12.5%) had their low back pain symptoms alleviated, 1 case (3.1%) slightly improved, 3 cases (9.4%) aggravated and 22 cases (68.8%) had no change in symptoms. According to VAS and ODI scores taken at different time points, these two scores gradually decreased over time; however, no statistical significances were found (VAS: F = 3.049, P > 0.05; ODI: F = 2. 272, P > 0.05).
  
  
  CONCLUSIONS
  The disease course of discogenic low back pain is chronic and persistent so that its symptoms show no improvement over time.
authors.affiliation: Department of Spine Surgery, General Hospital of Armed Police Force, Beijing 100039, China. pengbaogan@163.com
authors.forename: Bao-gan
authors.initials: BG
authors.lastname: Peng
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Pang
authors.forename: Duan-Ming
authors.initials: DM
authors.lastname: Li
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Zhang
authors.forename: Zheng-Da
authors.initials: ZD
authors.lastname: Kuang
authors.forename: Ming-Kui
authors.initials: MK
authors.lastname: Du
authors.forename: Chun-Hun
authors.initials: CH
authors.lastname: Gao
mesh_terms: D000328:Adult; D001175:Arthrography; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000175:diagnosis; D017116:Low Back Pain / Q000175:diagnosis* / Q000209:etiology; D008159:Lumbar Vertebrae; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D055815:Young Adult