title: Does Electrodiagnostic Confirmation of Radiculopathy Predict Pain Reduction after Transforaminal Epidural Steroid Injection? A Multicenter Study.
abstract: OBJECTIVE
  Minimal definitive literature identifies patients with radicular pain who would benefit most from epidural steroid injection (ESI). This study investigated if electromyographic (EMG) confirmation of radiculopathy with active or chronic denervation predicts a positive treatment outcome following ESI.
  
  
  METHODS
  Longitudinal cohort study of adults who underwent EMG and subsequent transforaminal ESI within 6 months. The proportion of individuals who experienced >50% pain relief and mean change in daily morphine equivalents (DME) were calculated.
  
  
  RESULTS
  170 individuals with respective mean (Standard Deviation) age and duration of symptoms of 55 (15) years and 36 (56) months were included. Mean time to <30 day and >30 day follow-up post-injection were 18 (6) and 99 (130) days, respectively. At >30 day follow-up, a larger proportion of EMG-confirmed individuals (37.7%) reported >50% pain reduction compared to EMG-negative individuals (17.8%) (p=0.03). This was significant for lumbosacral (40% vs. 15%, p=0.01) but not cervical symptoms (p>0.05). Mean decrease in DME at long-term follow-up in EMG-confirmed compared to EMG-negative individuals trended toward significance (-4 vs. -1, p=0.11). There was no significant relationship between myotomal spontaneous activity and pain or opioid use.
  
  
  CONCLUSIONS
  Needle EMG predicts long-term pain reduction from transforaminal ESI in patients with lumbosacral radiculopathy, regardless of the presence of active denervation.
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: McCormick
authors.affiliation: Department of PM&R, University of Utah, Salt Lake City, UT, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cushman
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Caldwell
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Marshall
authors.affiliation: Department of Pediatrics, Northwestern University Lurie Children's Hospital, Chicago, IL, USA.
authors.forename: Leda
authors.initials: L
authors.lastname: Ghannad
authors.affiliation: Department of PM&R, Harvard Medical School/Spaulding, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Eng
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Jaymin
authors.initials: J
authors.lastname: Patel
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Makovitch
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Chu
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Ashwin N
authors.initials: AN
authors.lastname: Babu
authors.affiliation: Department of PM&R, Harvard Medical School/Spaulding, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Walega
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Marciniak
authors.affiliation: Department of PM&R, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Press
authors.affiliation: Department of Orthopaedics, Stanford University. Palo Alto, CA, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kennedy
authors.affiliation: Department of PM&R, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Plastaras
keywords: Electromyography; Prediction tool; cervical; epidural; lumbar; lumbosacral; pain; radiculopathy