title: A New Method for Sham-Controlled Acupuncture in Experimental Visceral Pain - a Randomized, Single-Blinded Study.
abstract: Acupuncture is increasingly used as an alternative to medical therapy for various pain conditions. To study the effect of acupuncture in experimental and clinical studies, a control condition with sham acupuncture is needed. However, as such models have not been established in assessment of acupunctures effect against visceral pain, this study aimed to validate a new method for blinded sham acupuncture in experimental rectal pain.
  
  
  
  Fifteen subjects underwent a sequence of either sham or real acupuncture in randomized order. In the sham arm, a hollow inner tube with a sharp tip was fitted into an outer tube and subjects were blinded to the stimulations. Before and after the intervention, pain was induced by rectal stimulation with an inflatable balloon distended until the subjects' pain threshold was reached. The resting electroencephalogram (EEG) was quantified by spectral power analysis to explore the central nervous system effects objectively. Additionally, after the second study day, the subject was asked to indicate the sequence of interventions.
  
  
  
  A significant increase in rectal balloon volume was observed after sham 12 ± 21 mL (P = 0.049) and acupuncture 17 ± 30 mL (P = 0.046). However, the change in volume was not different between groups (P = 0.6). No differences in EEG spectral power distributions between sham and acupuncture were seen (all P > 0.6). The correct sequence of sham and acupuncture was indicated by 36% of the subjects (P = 0.4).
  
  
  
  The presented sham procedure provides a valid method for blinding of "sham acupuncture" and may be used in future blinded controlled trials of acupuncture for visceral pain.
authors.affiliation: Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Juel
authors.affiliation: Istituto Paracelso, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Liguori
authors.affiliation: Istituto Paracelso, Rome, Italy.|Department of Anatomic, Histologic, Forensic Medicine and Locomotor System Sciences, Faculty of Pharmacy and Medicine, Sapienza University, Rome, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Liguori
authors.affiliation: Department of Neurology, Paediatric Hospital Bambino Gesù, Rome, Italy.|Center for Sensory-Motor Interaction, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Valeriani
authors.affiliation: Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Carina
authors.initials: C
authors.lastname: Graversen
authors.affiliation: Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Søren S
authors.initials: SS
authors.lastname: Olesen
authors.affiliation: Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.|Center for Sensory-Motor Interaction, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark.
authors.forename: Asbjørn M
authors.initials: AM
authors.lastname: Drewes
mesh_terms: D015670:Acupuncture Therapy / Q000379:methods*; D000328:Adult; D035061:Control Groups; D018592:Cross-Over Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold; D010812:Physical Stimulation; D010865:Pilot Projects; D012002:Rectal Diseases / Q000628:therapy; D012107:Research Design; D016037:Single-Blind Method; D059265:Visceral Pain / Q000628:therapy*; D055815:Young Adult
keywords: EEG; abdominal pain; acupuncture; experimental visceral pain; sham acupuncture; sham-controlled; spectral power analysis