• Media type: E-Article
  • Title: The prevalence of redundant nerve roots in patients with lumbar spinal stenosis is body position dependent: a retrospective observational study with repeated measures design in an upright MRI scanner
  • Contributor: Papavero, Luca; Ebert, Stella; Marques, Carlos J.
  • imprint: Springer Science and Business Media LLC, 2020
  • Published in: Neuroradiology
  • Language: English
  • DOI: 10.1007/s00234-020-02423-x
  • ISSN: 0028-3940; 1432-1920
  • Keywords: Cardiology and Cardiovascular Medicine ; Neurology (clinical) ; Radiology, Nuclear Medicine and imaging
  • Origination:
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  • Description: <jats:title>Abstract</jats:title><jats:sec> <jats:title>Purpose</jats:title> <jats:p>Redundant nerve roots (RNRs) are a negative prognostic factor in patients with central lumbar spinal stenosis (LSS). Forty percent of candidates for surgical decompression show RNRs (RNR+) on preoperative conventional magnetic resonance imaging (MRI). We investigated the prevalence of RNRs in three functional postures (standing, neutral sitting and flexed sitting) with an upright MRI (upMRI).</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>A retrospective observational study with a repeated measures design. Thirty surgical candidates underwent upMRI. Sagittal and axial T2-weighted images of the three functional postures were evaluated. The segmental length of the lumbar spine (sLLS), the lordotic angle (LA) and the dural cross-sectional area (DCSA) were measured in each body position. Generalized linear mixed models were carried out. The 0.05 level of probability was set as the criterion for statistical significance.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>The prevalence of RNRs decreased from 80% during standing to 16.7% during flexed sitting (<jats:italic>p</jats:italic> &lt; 0.001). The sLLS increased significantly from standing to neutral sitting in both RNR groups (<jats:italic>p</jats:italic> &lt; 0.001). The increase from neutral sitting to flexed sitting was only significant (<jats:italic>p</jats:italic> &lt; 0.001) for the group without RNRs (RNR−). The LA decreased significantly for both RNR groups from standing to flexed sitting (<jats:italic>p</jats:italic> &lt; 0.001). The DSCA increased significantly in the RNR− group (<jats:italic>p</jats:italic> &lt; 0.001) but not in the RNR+ group (<jats:italic>p</jats:italic> = 0.9).</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>The prevalence of RNRs is body position dependent. Increases in DCSA play a determinant role in resolving RNRs.</jats:p> </jats:sec>