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Characterizing repeater F waves using the compound muscle action potential scan and machine learning techniques. Neurophysiol Clin 2025 Sep;55(5):103076

Date

05/10/2025

Pubmed ID

40345081

Pubmed Central ID

PMC13048848

DOI

10.1016/j.neucli.2025.103076

Scopus ID

2-s2.0-105004640987 (requires institutional sign-in at Scopus site)

Abstract

OBJECTIVES: The purpose of this study is to introduce a new analytical technique on repeater F waves (RFws) using compound muscle action potential (CMAP) scan and new features to differentiate the nerves innervating hand muscles.

METHODS: Twenty-four healthy subjects participated in the CMAP scan study. Tests were performed on the abductor pollicis brevis (APB) and abductor digit minimi (ADM) muscles. RFws were extracted using unsupervised machine learning and analyzed through conventional characteristics such as amplitude, latency, indices of F repeaters and total F repeaters, as well by new variables, including relative stimulus intensity (ReSI), relative F/M ratio (RF/MR), and range of stimulation intensity (RaSI).

RESULTS: Significantly higher indices of F repeaters (APB: 18.42±4.92 %, ADM: 13.58±4.68 %, p < 0.005) and total F repeaters (APB: 34.75±7.8 %, ADM: 26.67±8.56 %, p < 0.005) were observed in the APB compared with the ADM muscles. The ReSI (Z = 13.81, p < 0.001) and RaSI (Z=-2.46, p < 0.05) showed significant differences between the two muscles.

DISCUSSION AND CONCLUSION: This study provides normative data for RFws based on the CMAP scan recording and identifies different characteristics of repeaters between APB and ADM muscles. Findings of the study improve understanding of motoneuron physiological properties in hand muscles. The CMAP scan-based F wave analysis can be combined with motor unit number estimation technique to provide insights into surviving motoneuron function in neurological disorders.

Author List

Li X, Chen M, Barkhaus PE, Nandedkar SD, Cierny M, Moore C, Zhou P

Authors

Paul E. Barkhaus MD Adjunct Professor in the Neurology department at Medical College of Wisconsin
Marek Cierny MD Assistant Professor in the Neurology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Action Potentials
Adult
Electromyography
Female
Hand
Humans
Machine Learning
Male
Muscle, Skeletal
Young Adult