title: Comparison of tonic spinal cord stimulation, high-frequency and burst stimulation in patients with complex regional pain syndrome: a double-blind, randomised placebo controlled trial.
abstract: BACKGROUND
  Complex Regional Pain Syndrome (CRPS) is a disabling disease that is sometimes difficult to treat. Although spinal cord stimulation (SCS) can reduce pain in most patients with CRPS, some do not achieve the desired reduction in pain. Moreover, the pain reduction can diminish over time even after an initially successful period of SCS. Pain reduction can be regained by increasing the SCS frequency, but this has not been investigated in a prospective trial. This study compares pain reduction using five SCS frequencies (standard 40 Hz, 500 Hz, 1200 Hz, burst and placebo stimulation) in patients with CRPS to determine which of the modalities is most effective.
  
  
  METHODS
  All patients with a confirmed CRPS diagnosis that have unsuccessfully tried all other therapies and are eligible for SCS, can enroll in this trial (primary implantation group). CRPS patients that already receive SCS therapy, or those previously treated with SCS but with loss of therapeutic effect over time, can also participate (re-implantation group). Once all inclusion criteria are met and written informed consent obtained, patients will undergo a baseline assessment (T0). A 2-week trial with SCS is performed and, if successful, a rechargeable internal pulse generator (IPG) is implanted. For the following 3 months the patient will have standard 40 Hz stimulation therapy before a follow-up assessment (T1) is performed. Those who have completed the T1 assessment will enroll in a 10-week crossover period in which the five SCS frequencies are tested in five periods, each frequency lasting for 2 weeks. At the end of the crossover period, the patient will choose which frequency is to be used for stimulation for an additional 3 months, until the T2 assessment.
  
  
  CONCLUSIONS
  Currently no trials are available that systematically investigate the importance of variation in frequency during SCS in patients with CRPS. Data from this trial will provide better insight as to whether SCS with a higher frequency, or with burst stimulation, results in more effective pain relief.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN36655259.
authors: Center for Pain Medicine, Erasmus University Medical Center, Postbox 2040, 3000 CA, Rotterdam, The Netherlands. n.kriek@erasmusmc.nl.
authors: N
authors: N
authors: Kriek
authors: Center for Pain Medicine, Erasmus University Medical Center, Postbox 2040, 3000 CA, Rotterdam, The Netherlands. j.groeneweg@erasmusmc.nl.
authors: J G
authors: JG
authors: Groeneweg
authors: Center for Pain Medicine, Erasmus University Medical Center, Postbox 2040, 3000 CA, Rotterdam, The Netherlands. d.stronks@erasmusmc.nl.
authors: D L
authors: DL
authors: Stronks
authors: Center for Pain Medicine, Erasmus University Medical Center, Postbox 2040, 3000 CA, Rotterdam, The Netherlands. f.huygen@erasmusmc.nl.
authors: F J P M
authors: FJ
authors: Huygen
mesh_terms: D000041:Absenteeism; D000700:Analgesics / Q000191:economics / Q000627:therapeutic use; D003131:Combined Modality Therapy; D020918:Complex Regional Pain Syndromes / Q000188:drug therapy / Q000191:economics / Q000503:physiopathology / Q000628:therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005102:Health Expenditures; D006801:Humans; D053581:Muscle Strength Dynamometer; D010147:Pain Measurement; D058748:Pain Perception; D017288:Pain Threshold; D010292:Paresthesia / Q000503:physiopathology / Q000628:therapy; D011446:Prospective Studies; D012881:Skin Temperature; D062187:Spinal Cord Stimulation / Q000191:economics / Q000379:methods*; D013817:Thermography; D016896:Treatment Outcome
chemical_list: D000700:Analgesics