Short-interval intracortical inhibition and manual dexterity in healthy aging

Michelle Marneweck, Andrea Loftus, Geoff Hammond

Research output: Contribution to journalArticleResearchpeer-review

50 Citations (Scopus)

Abstract

Short-interval intracortical inhibition (SICI) acting on the first dorsal interosseus was measured using paired-pulse transcranial magnetic stimulation (interstimulus interval = 2. ms) in samples of young and healthy older subjects and correlated with manual dexterity measured with the Purdue Pegboard test and two isometric force-matching tasks. There was an age-related decrease in SICI and an age-related decline in all dexterity measures. The level of SICI was not correlated with any of the dexterity measures, but the appearance of atypical facilitation (rather than inhibition) in some subjects was associated with impaired pegboard performance but not force-matching performance. We conclude that SICI at rest is reduced with healthy aging but this loss of SICI does not directly contribute to the loss of dexterity; a shift in the balance of facilitatory and inhibitory processes in motor cortex to facilitation might interfere with sequenced hand movements.

Original languageEnglish
Pages (from-to)408-414
Number of pages7
JournalNeuroscience Research
Volume70
Issue number4
DOIs
Publication statusPublished - 1 Aug 2011
Externally publishedYes

Keywords

  • Aging
  • Manual dexterity
  • Motor control
  • SICI
  • TMS

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