title: Spinal cord stimulation for axial low back pain: a prospective, controlled trial comparing dual with single percutaneous electrodes.
abstract: METHODS
  A prospective, controlled, clinical trial comparing single and dual percutaneous electrodes in the treatment of axial low back pain from failed back surgery syndrome.
  
  
  OBJECTIVE
  To clarify technical requirements and test the hypothesis that placing two linear arrays in parallel, thereby doubling the number of contacts, improves outcome.
  
  
  BACKGROUND
  Technical improvements have enhanced outcomes of spinal cord stimulation for chronic axial low back pain. Dual, parallel electrodes reportedly improve these outcomes.
  
  
  METHODS
  Acting as their own controls, 20 patients who passed screening with single, 4-contact electrodes received permanent dual, 4-contact electrodes with 7- or 10-mm intercontact distances at the same vertebral level(s). We quantified and compared the technical and clinical results of the single and dual electrodes, adjusting stimulation parameters to specific psychophysical thresholds.
  
  
  RESULTS
  Single electrodes provided significant (P < 0.01) advantages in patient- and computer-calculated ratings of pain coverage by paresthesias and in the scaled amplitude necessary to cover the low back, compared with dual 7-mm electrodes. Slight advantages without statistical significance were observed for the single over the dual 10-mm electrodes. Amplitude requirements were significantly lower for the single electrode than for either dual electrode. At long-term follow-up, 53% of patients met the criteria for clinical success.
  
  
  CONCLUSIONS
  While we observed disadvantages for dual electrodes in treating axial low back pain, we achieved technical success with single or dual electrodes in most patients and maintained this success clinically with dual electrodes in 53%.
authors.affiliation: Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287-7881, USA. RNorth@jhmi.edu
authors.forename: Richard B
authors.initials: RB
authors.lastname: North
authors.forename: David H
authors.initials: DH
authors.lastname: Kidd
authors.forename: John
authors.initials: J
authors.lastname: Olin
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Sieracki
authors.forename: Farrokh
authors.initials: F
authors.lastname: Farrokhi
authors.forename: Loredana
authors.initials: L
authors.lastname: Petrucci
authors.forename: Protagoras N
authors.initials: PN
authors.lastname: Cutchis
mesh_terms: D000328:Adult; D000368:Aged; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010148:Intractable Pain / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D013116:Spinal Cord / Q000503:physiopathology*; D004561:Transcutaneous Electric Nerve Stimulation / Q000295:instrumentation* / Q000379:methods*; D016896:Treatment Outcome