Novel functional imaging technique for the brachial plexus based on magnetoneurography

• Published in: Clinical neurophysiology Vol. 130; no. 11; pp. 2114 - 2123
• Main Authors: Watanabe, Taishi, Kawabata, Shigenori, Hoshino, Yuko, Ushio, Shuta, Sasaki, Toru, Miyano, Yuki, Ozaki, Isamu, Adachi, Yoshiaki, Sekihara, Kensuke, Okawa, Atsushi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2019
• Subjects: Brachial plexus; Conduction velocity; Evoked magnetic field; Magnetoneurography; Median nerve; Ulnar nerve; Evoked magnetic field; Brachial plexus; CNAP; SQUID; CMAP; MNG; Conduction velocity; SNAP; UGRENS; Ulnar nerve; Magnetoneurography; Median nerve; SEP
• ISSN: 1388-2457; 1872-8952; 1872-8952
• DOI: 10.1016/j.clinph.2019.08.006

•Neural activity in the brachial plexus can be visualized by magnetoneurography.•Conductions in response to median and ulnar nerve stimulations can be differentiated.•Currents flowing into the depolarization site can be computationally reconstructed. To visualize neural activity in the brachial plexus using magnetoneurography (MNG). Using a 124- or 132-channel biomagnetometer system with a superconducting quantum interference device, neuromagnetic fields above the clavicle and neck region were recorded in response to electrical stimulation of the median and ulnar nerves in five asymptomatic volunteers (four men and one woman; age, 27–45 years old). Equivalent currents were computationally reconstructed from neuromagnetic fields and visualized as pseudocolor maps. Reconstructed currents at the depolarization site and compound nerve action potentials (CNAPs) at Erb’s point were compared. Neuromagnetic fields were recorded in all subjects. The reconstructed equivalent currents propagated into the vertebral foramina, and the main inflow levels differed between the median nerve (C5/C6–C7/T1 vertebral foramen) and the ulnar nerve (C7/T1–T1/T2). The inward current peaks at the depolarization site and CNAPs showed high linear correlation. MNG visualizes neural activity in the brachial plexus and can differentiate the conduction pathways after median and ulnar nerve stimulations. In addition, it can visualize not only the leading and trailing components of intra-axonal currents, but also inward currents at the depolarization site. MNG is a novel and promising functional imaging modality for the brachial plexus.