title: The analgesic effect of electroacupuncture on acute thermal pain perception--a central neural correlate study with fMRI.
abstract: BACKGROUND
  Electrical acupuncture (EA) has been utilized in acute pain management. However, the neuronal mechanisms that lead to the analgesic effect are still not well defined. The current study assessed the intensity [optimal EA (OI-EA) vs. minimal EA (MI-EA)] effect of non-noxious EA on supraspinal regions related to noxious heat pain (HP) stimulation utilizing an EA treatment protocol for acute pain and functional magnetic resonance imaging (fMRI) with correlation in behavioral changes. Subjects underwent five fMRI scanning paradigms: one with heat pain (HP), two with OI-EA and MI-EA, and two with OI-EA and HP, and MI-EA and HP.
  
  
  RESULTS
  While HP resulted in activations (excitatory effect) in supraspinal areas known for pain processing and perception, EA paradigms primarily resulted in deactivations (suppressive effect) in most of these corresponding areas. In addition, OI-EA resulted in a more robust supraspinal sedative effect in comparison to MI-EA. As a result, OI-EA is more effective than MI-EA in suppressing the excitatory effect of HP in supraspinal areas related to both pain processing and perception.
  
  
  CONCLUSIONS
  Intensities of EA plays an important role in modulating central pain perception.
authors.affiliation: Anesthesia Service, Veteran Administrations San Diego Healthcare System, 3350 La Jolla Village Drive, MC 125, San Diego, CA 92161, USA.
authors.forename: Shivshil
authors.initials: S
authors.lastname: Shukla
authors.forename: Artour
authors.initials: A
authors.lastname: Torossian
authors.forename: Jeng-Ren
authors.initials: JR
authors.lastname: Duann
authors.forename: Albert
authors.initials: A
authors.lastname: Leung
mesh_terms: D015667:Acupuncture Analgesia / Q000379:methods*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D015671:Electroacupuncture / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D058748:Pain Perception / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology; D013696:Temperature; D055815:Young Adult