Article thumbnail

Cortical representation of pain in primary sensory-motor areas (S1/M1)-a study using intracortical recordings in humans

By Maud Frot, Michel Magnin, François Mauguiere and Luis Garcia-Larrea


International audienceIntracortical evoked potentials to nonnoxious Aβ (electrical) and noxious Aδ (laser) stimuli within the human primary somatosensory (S1) and motor (M1) areas were recorded from 71 electrode sites in 9 epileptic patients. All cortical sites responding to specific noxious inputs also responded to nonnoxious stimuli, while the reverse was not always true. Evoked responses in S1 area 3b were systematic for nonnoxious inputs, but seen in only half of cases after nociceptive stimulation. Nociceptive responses were systematically recorded when electrode tracks reached the crown of the postcentral gyrus, consistent with an origin in somatosensory areas 1-2. Sites in the precentral cortex also exhibited noxious and nonnoxious responses with phase reversals indicating a local origin in area 4 (M1). We conclude that a representation of thermal nociceptive information does exist in human S1, although to a much lesser extent than the nonnociceptive one. Notably, area 3b, which responds massively to nonnoxious Aβ activation was less involved in the processing of noxious heat. S1 and M1 responses to noxious heat occurred at latencies comparable to those observed in the supra-sylvian opercular region of the same patients, suggesting a parallel, rather than hierarchical, processing of noxious inputs in S1, M1 and opercular cortex. This study provides the first direct evidence for a spinothalamic related input to the motor cortex in humans

Topics: evoked potentials, human, motor cortex, pain, somatosensory cortex, MESH: Adult, MESH: Brain Mapping, MESH: Humans, MESH: Lasers, MESH: Magnetic Resonance Imaging, MESH: Male, MESH: Median Nerve, MESH: Motor Cortex, MESH: Multimodal Imaging, MESH: Nociception, MESH: Nociceptive Pain, MESH: Pain Measurement, MESH: Cerebral Angiography, MESH: Reaction Time, MESH: Somatosensory Cortex, MESH: Stereotaxic Techniques, MESH: Young Adult, MESH: Cerebral Cortex, MESH: Electrodes, Implanted, MESH: Electroshock, MESH: Epilepsies, Partial, MESH: Evoked Potentials, Somatosensory, MESH: Female, MESH: Hot Temperature, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
Publisher: 'Wiley'
Year: 2013
DOI identifier: 10.1002/hbm.22097
OAI identifier: oai:HAL:hal-02472440v1
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://hal.archives-ouvertes.... (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.