MeRef: Multivariable extrapolated reference values in motor nerve conduction studies
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Updated: Nov 17, 2025

In Vivo Electrophysiological Measurement of the Rat Ulnar Nerve with Axonal Excitability Testing
Published on: February 6, 2018
Sanjeev D Nandedkar1,2, Erik V Stålberg3, Paul E Barkhaus2
1Natus Medical, Inc, Hopewell Junction, New York, USA.
Introduction:
In this study we describe a method called "multivariable extrapolated reference values" (MeRef) that derives reference values (RVs) using patient data and includes the dependence of these variables on multiple patient demographic variables, such as age and height.
Methods:
Computer simulations were used to generate "normal" and "patient" nerve conduction data. Median, ulnar, and tibial motor nerve conduction data from 500 patients studied were tabulated. Data were analyzed using the MeRef method.
Results:
The simulations showed great similarity between RVs obtained from MeRef of "patient" data and traditional analysis of "normal" data. In the real patient data, MeRef gave RVs as regression equations based on patient age and/or height.
Discussion:
MeRef can provide RVs by including patient demographic data and does not require subject grouping. It provides parameters of multivariable linear regression and standard deviation, and requires a few hundred patient studies to define reference values.

