Sural sensory nerve action potential, epidermal nerve fiber density, and quantitative sudomotor axon reflex in the healthy elderly

Jinny O. Tavee, David Polston, Lan Zhou, Robert W. Shields, Robert S. Butler, Kerry H. Levin

Research output: Contribution to journalArticle

19 Scopus citations


Introduction: Polyneuropathy evaluation in older patients is often challenging due to conflicting data regarding normative values for peripheral nerve testing. Methods: We characterized the results of sural nerve conduction studies, intraepidermal nerve fiber density (IENFD), and quantitative sudomotor axon reflex testing (QSART) in a prospective study of 50 healthy subjects aged ≥60 years. Results: Of the 50 subjects, 48 (96%) had an obtainable sural sensory nerve action potential (SNAP). Using quantile regression, we estimated the lower limit of normal (LLN) for sural amplitudes to be 3 μV for patients 60-70 years, 1 μV for those 70-74 years, and <1 μV (absent) for those ≥75 years of age. IENFD and QSART volume were reduced with advancing age, although IENFD was lower in men and QSART volume was lower in women. Conclusions: We propose that an absent sural SNAP in patients up to 75 years of age should be considered abnormal. Our findings also support age- and gender-stratified normative data for IENFD and QSART.

Original languageEnglish (US)
Pages (from-to)564-569
Number of pages6
JournalMuscle and Nerve
Issue number4
StatePublished - Apr 2014



  • Healthy elderly
  • Normative values
  • SNAP
  • Sural nerve

ASJC Scopus subject areas

  • Physiology
  • Clinical Neurology
  • Cellular and Molecular Neuroscience
  • Physiology (medical)

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