title: Neurophysiological responses to unpleasant stimuli (acute electrical stimulations and emotional pictures) are increased in patients with schizophrenia.
abstract: Patients with schizophrenia have often been described as insensitive to nociceptive signals, but objective evidence is sparse. We address this question by combining subjective behavioral and objective neurochemical and neurophysiological measures. The present study involved 21 stabilized and mildly symptomatic patients with schizophrenia and 21 control subjects. We applied electrical stimulations below the pain threshold and assessed sensations of pain and unpleasantness with rating scales, and Somatosensory Evoked Potentials (SEPs/EEG). We also measured attention, two neurochemical stress indices (ACTH/cortisol), and subjective VEPs/EEG responses to visual emotional stimuli. Our results revealed that, subjectively, patients' evaluations do not differ from controls. However, the amplitude of EEG evoked potentials was greater in patients than controls as early as 50 ms after electrical stimulations and beyond one second after visual processing of emotional pictures. Such responses could not be linked to the stress induced by the stimulations, since stress hormone levels were stable. Nor was there a difference between patients and controls in respect of attention performance and tactile sensitivity. Taken together, all indices measured in patients in our study were either heightened or equivalent relative to healthy volunteers.
authors.affiliation: INSERM U-1114, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Département de Psychiatrie, Hôpitaux Universitaires de Strasbourg; 1, place de l'Hôpital, 67000 Strasbourg, France.|Fondation FondaMental, Créteil, France.|Fondation APICIL, 21, place Bellecour, 69002 Lyon, France.
authors.forename: Céline Z
authors.initials: CZ
authors.lastname: Duval
authors.affiliation: Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, 5, rue Blaise Pascal, 67084 Strasbourg, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Goumon
authors.affiliation: INSERM U-1119 Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000 Strasbourg, France.|Laboratoire de Biochimie et Biologie Moléculaire, Hôpitaux Universitaire de Strasbourg, 67098 Strasbourg, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Kemmel
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, 79098 Freiburg, Germany.|University Eye-Hospital, Killianstraße 5, 79106 Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kornmeier
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Université de Strasbourg, CNRS, Strasbourg, France.
authors.forename: André
authors.initials: A
authors.lastname: Dufour
authors.affiliation: EA 481 Laboratoire de Neurosciences, Université de Franche-Comte, 1 place du maréchal Leclerc, 25030 Besançon Cedex, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Andlauer
authors.affiliation: INSERM U-1114, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Département de Psychiatrie, Hôpitaux Universitaires de Strasbourg; 1, place de l'Hôpital, 67000 Strasbourg, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Vidailhet
authors.affiliation: Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, 5, rue Blaise Pascal, 67084 Strasbourg, France.
authors.forename: Pierrick
authors.initials: P
authors.lastname: Poisbeau
authors.affiliation: Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, 5, rue Blaise Pascal, 67084 Strasbourg, France.|Centre 'Evaluation et de Traitement de la Douleur (CETD) du CHRU, Hôpital de Hautepierre, 1 av Moliere, 67078 Strasbourg, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Salvat
authors.affiliation: Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, 5, rue Blaise Pascal, 67084 Strasbourg, France.|Centre 'Evaluation et de Traitement de la Douleur (CETD) du CHRU, Hôpital de Hautepierre, 1 av Moliere, 67078 Strasbourg, France.
authors.forename: André
authors.initials: A
authors.lastname: Muller
authors.affiliation: INSERM U-1119 Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000 Strasbourg, France.
authors.forename: Ayikoé G
authors.initials: AG
authors.lastname: Mensah-Nyagan
authors.affiliation: Fondation FondaMental, Créteil, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Schmidt-Mutter
authors.affiliation: INSERM U-1114, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Département de Psychiatrie, Hôpitaux Universitaires de Strasbourg; 1, place de l'Hôpital, 67000 Strasbourg, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Giersch
mesh_terms: D000328:Adult; D004558:Electric Stimulation; D004569:Electroencephalography; D004644:Emotions; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D013315:Stress, Psychological / Q000503:physiopathology*