title: Peripheral nerve field stimulation for the management of localized chronic intractable back pain: results from a randomized controlled study.
abstract: OBJECTIVE
  Improved device technology has caused a renewed interest in peripheral nerve field stimulation (PNfS). This study sought to obtain preliminary estimates of the safety and efficacy of PNfS in patients with localized chronic intractable pain of the back.
  
  
  METHODS
  This Institutional Review Board-approved, prospective, randomized, controlled, crossover study consisted of two phases. During phase I, patients rotated through four stimulation groups (minimal, subthreshold, low frequency, and standard stimulation). If a 50% reduction in pain was achieved during any of the three active stimulation groups (responder), the patient proceeded to phase II, which began with implant of the permanent system and lasted 52 weeks. The primary endpoint was a reduction in pain, assessed by the visual analog scale (VAS). Analysis of variance, including the effects of patient, treatment, and study period, was used for phase I results. Phase II results were analyzed by paired t-tests.
  
  
  RESULTS
  A total of 44 patients were enrolled at five sites. Of these patients, 32 were implanted with a trial system and 30 completed phase I. During phase I, there were significant differences in mean VAS scores between minimal stimulation and subthreshold stimulation (p = 0.003), low frequency stimulation (p < 0.001), and standard stimulation (p < 0.001). Twenty-four patients were classified as responders to the therapy, and 23 patients received permanent system placement. Significant differences in VAS scores were observed between baseline and all follow-up visits during phase II (p < 0.001) CONCLUSIONS: The results provide evidence to support safety and effectiveness of PNfS as an aid in the management of chronic, localized back pain.
authors.affiliation: Holy Cross Orthopedic Institute, Fort Lauderdale, FL, USA.
authors.forename: W Porter
authors.initials: WP
authors.lastname: McRoberts
authors.forename: Richard
authors.initials: R
authors.lastname: Wolkowitz
authors.forename: D Joseph
authors.initials: DJ
authors.lastname: Meyer
authors.forename: Eugene
authors.initials: E
authors.lastname: Lipov
authors.forename: Jay
authors.initials: J
authors.lastname: Joshi
authors.forename: Bennet
authors.initials: B
authors.lastname: Davis
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Cairns
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Barolat
mesh_terms: D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000704:Analysis of Variance; D001416:Back Pain / Q000188:drug therapy / Q000628:therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D058542:Implantable Neurostimulators / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010148:Intractable Pain / Q000188:drug therapy / Q000628:therapy*; D010525:Peripheral Nerves; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid
keywords: chronic back pain; neuromodulation; peripheral nerve field; subcutaneous stimulation