title: Hyperexcitability in pain matrices in patients with fibromyalgia.
abstract: OBJECTIVE
  Emerging evidence associates fibromyalgia (FM) with pain system dysfunction. In this study, using laser evoked potentials (LEPs) and paired laser stimuli, we tested excitability in the pain matrices and sought possible changes in patients with FM.
  
  
  METHODS
  In 20 patients with FM and 15 healthy subjects, after recording control nociceptive system-mediated Aδ- and C-fibre-related LEPs, we measured excitability in the pain matrices by testing the Aδ-LEP conditioned by a preceding C-LEP.
  
  
  RESULTS
  No difference was found in control LEP amplitudes for Aδ- or C-fibres between patients and healthy subjects. Conversely, the Aδ-LEP amplitude, conditioned by a preceding C-LEP, was significantly higher in patients than in healthy subjects (p<0.001).
  
  
  CONCLUSIONS
  Objective evidence from increased conditioned Aδ-LEP amplitudes reflecting hyperexcitability in the pain matrices in FM, provides diagnostically useful information and might help in developing new therapeutic approaches.
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Truini
authors.affiliation: Rheumatology Unit, Department of Internal Medicine and Medical Specialities, Sapienza University of Rome, Rome, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Gerardi
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Di Stefano
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: La Cesa
authors.affiliation: Rheumatology Unit, Department of Internal Medicine and Medical Specialities, Sapienza University of Rome, Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Iannuccelli
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Pepe
authors.affiliation: Rheumatology Unit, Department of Internal Medicine, Luigi Sacco University Hospital, Milan, Italy.
authors.forename: Piercarlo
authors.initials: P
authors.lastname: Sarzi-Puttini
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Cruccu
authors.affiliation: Rheumatology Unit, Department of Internal Medicine and Medical Specialities, Sapienza University of Rome, Rome, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Di Franco
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004569:Electroencephalography; D005260:Female; D005356:Fibromyalgia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D066331:Laser-Evoked Potentials; D053844:Lasers, Solid-State; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated; D036421:Nerve Fibers, Unmyelinated; D010146:Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D010147:Pain Measurement; D058748:Pain Perception; D017288:Pain Threshold; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011930:Reaction Time; D013997:Time Factors