Evaluation of electrical activity at the carpal tunnel area in response to median nerve elbow stimulation using magnetoneurography

Shinji Sato; Miho Akaza; Toru Sasaki; Yuta Tanaka; Jun Hashimoto; Taishi Watanabe; Yuki Miyano; Sukchan Kim; Saeri Kaminaka; Yuki Sumi; Kensuke Sekihara; Yoshiaki Adachi; Shigenori Kawabata

doi:10.1016/j.clinph.2023.09.016

Evaluation of electrical activity at the carpal tunnel area in response to median nerve elbow stimulation using magnetoneurography

Clin Neurophysiol. 2023 Oct 13:156:89-97. doi: 10.1016/j.clinph.2023.09.016. Online ahead of print.

Authors

Shinji Sato¹, Miho Akaza², Toru Sasaki³, Yuta Tanaka⁴, Jun Hashimoto⁵, Taishi Watanabe⁶, Yuki Miyano⁷, Sukchan Kim⁸, Saeri Kaminaka⁹, Yuki Sumi¹⁰, Kensuke Sekihara¹¹, Yoshiaki Adachi¹², Shigenori Kawabata¹³

Affiliations

¹ RICOH Futures BU, RICOH Company. Ltd, 2-3-10 Kandasurugadai Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: shinji.s1.satoh@jp.ricoh.com.
² Department of Clinical Information Applied Science, Biomedical Laboratory Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: m-akaza.nuro@tmd.ac.jp.
³ Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: t-sasaki.orth@tmd.ac.jp.
⁴ Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: tanaka@atmtmd.onmicrosoft.com.
⁵ Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: hash.orth@tmd.ac.jp.
⁶ RICOH Futures BU, RICOH Company. Ltd, 2-3-10 Kandasurugadai Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: taishi.watanabe@jp.ricoh.com.
⁷ RICOH Futures BU, RICOH Company. Ltd, 2-3-10 Kandasurugadai Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: yuki.yh.hasegawa@jp.ricoh.com.
⁸ RICOH Futures BU, RICOH Company. Ltd, 2-3-10 Kandasurugadai Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: sukchan.kim@jp.ricoh.com.
⁹ RICOH Futures BU, RICOH Company. Ltd, 2-3-10 Kandasurugadai Chiyoda-ku, Tokyo 101-0062, Japan. Electronic address: Saeri.Kaminaka@jp.ricoh.com.
¹⁰ Department of Clinical Information Applied Science, Biomedical Laboratory Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: sumi-alg@umin.ac.jp.
¹¹ Department of Advanced Technology in Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: sekihara@nifty.com.
¹² Applied Electronics Laboratory, Kanazawa Institute of Technology, 7-1 Ogigaoka, Nonoichi, Ishikawa 921-8501, Japan. Electronic address: adachi@ael.kanazawa-it.ac.jp.
¹³ Department of Advanced Technology in Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: kawabata.orth@tmd.ac.jp.

PMID: 39492404
DOI: 10.1016/j.clinph.2023.09.016

Abstract

Objective: To develop a magnetic field measurement method in the carpal tunnel area in response to electrical median nerve stimulation at the elbow and evaluate its usefulness.

Methods: Five healthy subjects participated. The magnetic field recording evoked by median nerve electrical stimulation at the elbow with electrical intensity that minimized the pronator quadratus and flexor carpi radialis muscle response was measured with 132-channel superconducting quantum interference device magnetoneurography. The current distributions were reconstructed from magnetic fields with the spatial filter method. The magnetic fields evoked by electrical stimulation at the index distal interphalangeal joint were also measured.

Results: After median nerve elbow stimulation, intra-axonal current and inward currents flowing perpendicularly to the nerve pathway were visualized. The mean ± SD inward current intensity at the center of the carpal tunnel area was significantly larger with elbow stimulation than with index distal interphalangeal joint stimulation: 1.11 ± 0.65 nAm versus 0.51 ± 0.15 nAm (p = 0.047).

Conclusions: Magnetic field measurement in the carpal tunnel area with adjusted submaximal stimulation at the elbow can detect larger signals compared with digit stimulation.

Significance: This method has the potential to be more useful for the examination of carpal tunnel syndrome patients.

Keywords: Carpal tunnel; Elbow stimulation; Magnetoneurography; Median nerve.