title: Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis.
abstract: To evaluate the association of redundant nerve roots of cauda equina (RNRCE) with the degree of lumbar spinal stenosis (LSS) and with spondylolisthesis.
  
  
  METHODS
  After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA) was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra- and inter-observer reproducibility was assessed.
  
  
  RESULTS
  RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis<55 mm2. Substantial intra- observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE.
  
  
  CONCLUSIONS
  LSS is a risk factor for RNRCE, especially for dural sac CSA<55 mm2. LSS and spondylolisthesis are independent risk factors for RNRCE.
authors.affiliation: Radiology Division, School of Medicine of Ribeirao Preto,, University of Sao Paulo (USP), Ribeirao Preto, SP, Brazil.
authors.forename: Leonor Garbin
authors.initials: LG
authors.lastname: Savarese
authors.affiliation: Centro de Recursos Diagnósticos, Goiânia, GO, Brazil.
authors.forename: Geraldo Dias
authors.initials: GD
authors.lastname: Ferreira-Neto
authors.affiliation: Department of Biomechanics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Carlos Fernando Pereira da Silva
authors.initials: CF
authors.lastname: Herrero
authors.affiliation: Department of Biomechanics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Helton Luiz Aparecido
authors.initials: HL
authors.lastname: Defino
authors.affiliation: Radiology Division, School of Medicine of Ribeirao Preto,, University of Sao Paulo (USP), Ribeirao Preto, SP, Brazil.
authors.forename: Marcello H
authors.initials: MH
authors.lastname: Nogueira-Barbosa
mesh_terms: D016022:Case-Control Studies; D002420:Cauda Equina / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015588:Observer Variation; D012307:Risk Factors; D012720:Severity of Illness Index; D013126:Spinal Nerve Roots / Q000473:pathology*; D013130:Spinal Stenosis / Q000473:pathology*; D013168:Spondylolisthesis / Q000473:pathology*