title: Some epidurographic explanations for incomplete epidural analgesia coverage in the absence of a catheter.
abstract: OBJECTIVE
  To determine the impact of the plica mediana dorsalis (PMD) on injected contrast media spread in the epidural space.
  
  
  METHODS
  Prospective interventional study.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  30 chronic pain patients ranging in age from 37 to 71 years, undergoing epidural steroid injection.
  
  
  METHODS
  Epidurograms were evaluated for the 1) presence or absence of a PMD and 2) bilateral differential density and the extent of contrast spread on either side of the midline, horizontally and vertically.
  
  
  RESULTS
  The PMD (defined as midline radiolucency in epidurograms) was observed in (80%) 24/30 patients based on the epidurograms that were evaluated. Denser contrast spread on one side was found in (79%) 19/24 patients who had the PMD and in (33%) 2/6 patients who did not have the PMD (P = 0.03). Horizontal and vertical asymmetrical spread of the contrast was observed in (67%) 16 of 24 patients with the PMD and in (50%) 3 of 6 of patients without the PMD in each direction independently.
  
  
  CONCLUSIONS
  The difference in density of contrast spread on either side of the midline carries important clinical implications in understanding the pathogenesis of inadequate epidural analgesia and/or unilateral excessive motor weakness or numbness.
authors.affiliation: Department of Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Assistant Consultant, Department of Anaesthesia and Pain Management, King AbdulAziz Medical City Saudi Arabia, Riyadh, Saudi Arabia; Lecturer, Department of Anesthesia, Alexandria University, Alexandria, Egypt. Electronic address: EmNada@uams.edu.
authors.forename: Eman M S
authors.initials: EM
authors.lastname: Nada
authors.forename: Mehmet Alparslan
authors.initials: MA
authors.lastname: Turan
authors.forename: Mona N
authors.initials: MN
authors.lastname: Mohamed
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D015360:Analgesia, Epidural / Q000379:methods*; D059350:Chronic Pain / Q000188:drug therapy*; D003287:Contrast Media / Q000008:administration & dosage* / Q000378:metabolism; D004824:Epidural Space / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D003287:Contrast Media
keywords: Analgesia: labor; Contrast spread; Epidurography; Obstetrical anesthesia; Plica mediana dorsalis