title: Effect of spinal cord stimulation on sensory characteristics: a randomized, blinded crossover study.
abstract: OBJECTIVE
  Spinal cord stimulation (SCS) is increasingly used to treat various chronic pain conditions. One undetermined issue is to what extent SCS alters the processing of sensory information from the periphery, including those stimuli that are mediated by small-fiber populations. We aimed to investigate these possible changes using quantitative sensory testing (QST).
  
  
  METHODS
  Fourteen patients in long-term SCS treatment for complex regional pain syndrome (n=5) or pain following peripheral nerve injury (n=9) were examined with QST. All patients answered questions about their pain and underwent QST while the SCS treatment was activated and deactivated (12 h interval between the sessions) in a randomized, double-blinded crossover setting. Both the painful side and the corresponding contralateral side were examined.
  
  
  RESULTS
  Thermal and mechanical thresholds were similar during SCS activation and deactivation. The same result was found for intensity of pain and areas with painful symptoms even though all patients had documented long-term benefit of the treatment.
  
  
  CONCLUSIONS
  The results support existing evidence suggesting that SCS does not change sensory characteristics, which is important information for both patients and clinicians. Changes in pain intensity after deactivation of SCS may be different in short-term and long-term SCS treatment.
authors.affiliation: *Danish Pain Research Center Departments of †Neurosurgery ‡Anesthesiology §Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kaare
authors.initials: K
authors.lastname: Meier
authors.forename: Lone
authors.initials: L
authors.lastname: Nikolajsen
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Sørensen
authors.forename: Troels S
authors.initials: TS
authors.lastname: Jensen
mesh_terms: D059350:Chronic Pain / Q000209:etiology / Q000628:therapy*; D020918:Complex Regional Pain Syndromes / Q000628:therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology; D059348:Peripheral Nerve Injuries / Q000150:complications; D062187:Spinal Cord Stimulation / Q000379:methods*