title: The influence of the 5-HT3 receptor antagonist tropisetron on pain in fibromyalgia: a functional magnetic resonance imaging pilot study.
abstract: OBJECTIVE
  Central pain processing is altered in patients with fibromyalgia syndrome (FMS). The serotonin metabolism, especially the 5-HT3 receptor, seems to play an important role.
  
  
  METHODS
  We investigated the effect of the local injection of the 5-HT3 receptor antagonist tropisetron on the perception and central processing of pain in FMS patients using painful mechanical stimulation and functional magnetic resonance imaging (fMRI) within the framework of a pre-/posttreatment double-blind design.
  
  
  RESULTS
  In the contralateral primary somatosensory cortex, contralateral posterior insula, and anterior cingulate cortex, we found that the activation was significantly reduced after treatment. On average, patients rated the stimulation-induced pain intensity as stronger in the session after treatment compared to before treatment, although the individual data revealed a heterogeneous pattern. All patients showed sensitisation during the painful stimulation, which was not influenced by the treatment.
  
  
  CONCLUSIONS
  Both the sensory-discriminative and motivational-affective components of pain as measured by fMRI were altered by tropisetron.
authors.affiliation: Department of Neuropsychology, University of Heidelberg, Central Institute of Mental Health, Mannheim, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Koeppe
authors.forename: C
authors.initials: C
authors.lastname: Schneider
authors.forename: K
authors.initials: K
authors.lastname: Thieme
authors.forename: S
authors.initials: S
authors.lastname: Mense
authors.forename: T
authors.initials: T
authors.lastname: Stratz
authors.forename: W
authors.initials: W
authors.lastname: Müller
authors.forename: H
authors.initials: H
authors.lastname: Flor
mesh_terms: D001921:Brain / Q000503:physiopathology; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D010865:Pilot Projects; D011985:Receptors, Serotonin / Q000627:therapeutic use*; D000077526:Tropisetron
chemical_list: D007211:Indoles; D011985:Receptors, Serotonin; D000077526:Tropisetron