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  • Valyear_2019_NI_acceptedManuscript

    Accepted author manuscript, 47 MB, PDF document

    Embargo ends: 19/10/20

    Licence: CC BY-NC-ND Show licence

DOI

  • Kenneth F Valyear
    University of Missouri, USA
  • Benjamin A Philip
    University of Missouri, USA
  • Carmen M Cirstea
    University of Missouri, USA
  • Pin-Wei Chen
    University of Missouri, USA
  • Nathan Baune
    University of Missouri, USA
  • Noah Marchal
    University of Missouri, USA
  • Scott H Frey
    University of Missouri, USA

Animal models reveal that deafferenting forelimb injuries precipitate reorganization in both contralateral and ipsilateral somatosensory cortices. The functional significance and duration of these effects are unknown, and it is unclear whether they also occur in injured humans. We delivered cutaneous stimulation during functional magnetic resonance imaging (fMRI) to map the sensory cortical representation of the intact hand and lower face in a group of chronic, unilateral, upper extremity amputees (N = 19) and healthy matched controls (N = 29). Amputees exhibited greater activity than controls within the deafferented former sensory hand territory (S1f) during stimulation of the intact hand, but not of the lower face. Despite this cortical reorganization, amputees did not differ from controls in tactile acuity on their intact hands. S1f responses during hand stimulation were unrelated to tactile acuity, pain, prosthesis usage, or time since amputation. These effects appeared specific to the deafferented somatosensory modality, as fMRI visual mapping paradigm failed to detect any differences between groups. We conclude that S1f becomes responsive to cutaneous stimulation of the intact hand of amputees, and that this modality-specific reorganizational change persists for many years, if not indefinitely. The functional relevance of these changes, if any, remains unknown.

Original languageEnglish
Article number116291
JournalNeuroimage
Early online date19 Oct 2019
DOIs
Publication statusE-pub ahead of print - 19 Oct 2019
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