Tibial motor and sural electrophysiological relationship in subjects without and patients with mild axonal peripheral neuropathy

  • Thomas Henry Julian
  • Ptolemaios Georgios Sarrigiannis
  • Ayesha Girach
  • Panagiotis ZisEmail author
Original article


The distal motor fibers of the tibial and sural nerves are predominantly derived from the S1 root. We aimed to describe the electrophysiological relationship of these two nerves. Clinical, radiological and neurophysiological data of patients with mild, length-dependent, peripheral neuropathy (PN) and subjects without PN were retrospectively collected and analyzed. Eighty-eight individuals without PN and 24 patients with mild axonal PN who had no evidence of lumbosacral radiculopathy were included for analysis. Significant positive correlations were observed for the tibial CMAP and the sural SNAP for both controls and patients. Multivariate linear regression analyses showed that the predicted tibial CMAP can be calculated using the following equations: for male subjects without PN, tibial CMAP = 20.7 − 0.21 × age; for female subjects without PN, tibial CMAP = 23.3 − 0.21 × age and for patients with mild PN, tibial CMAP = 2.7 + sural SNAP. This study demonstrates the high correlation between the tibial CMAP and the sural SNAP in subjects without PN and patients with mild axonal peripheral neuropathy, and provides mathematical equations for the calculation of the predicted tibial CMAP for such individuals.


Polyneuropathy Tibial nerve Sural nerve Electrodiagnostic Radiculopathy Screening 





Peripheral neuropathy


Sensory nerve action potential


Compound muscle action potential



This is a summary of an independent research supported by BRC and carried out at the National Institute for Health Research (NIHR) Sheffield Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the BRC, NHS, the NIHR or the Department of Health. Dr. Zis is sincerely thankful to the Ryder Briggs Fund. We are sincerely thankful to Dr. Dasappaiah Ganesh Rao for his contribution in the collection of the data.

Compliance with ethical standards

Conflict of interest

None of the authors have any conflict of interest to disclose.

Ethical approval

We confirm that we have read the journal’s position on issues involved in the ethical publication and affirm that this report is consistent with those guidelines.


  1. 1.
    Wilbourn AJ, Aminoff MJ (1988) AAEE minimonograph #32: the electrophysiologic examination in patients with radiculopathies. Muscle Nerve 11(11):1099–1114CrossRefGoogle Scholar
  2. 2.
    Esper GJ, Nardin RA, Benatar M, Sax TW, Acosta JA, Raynor EM (2005) Sural and radial sensory responses in healthy adults: diagnostic implications for polyneuropathy. Muscle Nerve 31(5):628–632CrossRefGoogle Scholar
  3. 3.
    Zis P, Hadjivassiliou M, Rao DG, Sarrigiannis PG (2019) Electrophysiological determinants of the clinical severity of axonal peripheral neuropathy. Muscle Nerve 59(4):491–493CrossRefGoogle Scholar

Copyright information

© Belgian Neurological Society 2019

Authors and Affiliations

  1. 1.Academic Department of NeurosciencesSheffield Teaching Hospitals NHS Foundation TrustSheffieldUK

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