Secondary somatosensory cortex is important for the sensory-discriminative dimension of pain: a functional MRI study

Authors

  • Christian Maihöfner,

    1. Institute of Physiology and Experimental Pathophysiology, Universitätsstrasse 17, 91054 Erlangen, University of Erlangen-Nuremberg, Germany
    2. Department of Neurology, Schwabachanlage 6, 91054 Erlangen, University of Erlangen-Nuremberg, Germany D-91054 Erlangen,
      Tel. 49-9131-852 2498, Fax: 49-9131-852 2497, E-mail: maihoefner@physiologie1.uni-erlangen.de
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    • *

      C.M. and B.H. contributed equally to this work.

  • Barbara Herzner,

    1. Institute of Physiology and Experimental Pathophysiology, Universitätsstrasse 17, 91054 Erlangen, University of Erlangen-Nuremberg, Germany
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    • *

      C.M. and B.H. contributed equally to this work.

  • Hermann Otto Handwerker

    1. Institute of Physiology and Experimental Pathophysiology, Universitätsstrasse 17, 91054 Erlangen, University of Erlangen-Nuremberg, Germany
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Dr C. Maihöfner, 1Institute of Physiology and Experimental Pathophysiology, as above.
E-mail: maihoefner@physiologie1.uni-erlangen.de

Abstract

A complex cortical network is believed to encode the multidimensionality of the human pain experience. In the present study, we used functional magnetic resonance imaging (fMRI) to examine whether the brain's processing of noxious stimuli differs with different psychophysical properties. Painful mechanical impact and heat stimulations of equal stimulus intensity were applied to the forearm of 14 subjects in a randomized order. Concomitantly, subjects had to evaluate the corresponding sensory-discriminative and affective-motivational pain dimensions. fMRI revealed an increased activation of bilateral secondary somatosensory cortices (S2) during mechanical impact pain compared with heat pain. Activations in S2 were significantly correlated with scores for the sensory-discriminative component during mechanical impact pain. By contrast, corresponding scores for the affective-motivational pain dimension did not differ between both conditions. In summary, we conclude that S2 plays an important role in the sensory-discriminative dimension of pain.

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