title: Dipolar source modelling of brain potentials evoked by painful electrical stimulation of the human sigmoid colon.
abstract: The aim of the study was to compare the cerebral generators following painful stimulation of the sigmoid colon and the abdominal skin in 11 healthy subjects. The evoked potentials (EPs) were recorded from 31 surface electrodes following painful electrical stimuli of the sigmoid colon, and of the referred pain area on the abdomen. Current dipole models estimating the EPs amplitude and topography were calculated. For colon stimulation, the earliest cortical activities were described by dipoles in the bilateral insula and in the anterior cingulate cortex, while both secondary somatosensory areas were activated later. When the skin was stimulated, early bilateral dipoles in the primary and secondary somatosensory areas were estimated, followed by a dipole in the frontal region. This suggests that painful cutaneous and visceral stimuli are processed differently in the brain.
authors.affiliation: Center for Visceral Biomechanics and Pain, Department of Medical Gastroenterology, Aalborg Hospital, Aalborg, Denmark. drewes@smi.auc.dk
authors.forename: Asbjørn Mohr
authors.initials: AM
authors.lastname: Drewes
authors.forename: Petra
authors.initials: P
authors.lastname: Rössel
authors.forename: Domenica
authors.initials: D
authors.lastname: Le Pera
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Valeriani
mesh_terms: D000005:Abdomen / Q000502:physiology; D000328:Adult; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000502:physiology*; D012809:Colon, Sigmoid / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology*