P3-6-03. Visualization of nerve impulse traveling along the brachial plexus after ulnar nerve stimulation using 132ch SQUID magnetoneurography system

Abstract

Using 132ch superconducting quantum interference device (SQUID) magnetoneurography sensor system, we succeeded in visualizing nerve impulse traveling along the brachial plexus (BP) after median nerve stimulation and propagating into the C5–C8 intervertebral foramen with participant’s X-ray imaging. Here we analyzed the nerve impulse traveling along BP following ulnar nerve stimulation at the wrist. Magnetoneurogram following wrist stimulation were measured over BP from 5 healthy volunteers. Somatosensory evoked potential (SEP) was simultaneously measured at Erb’s point for making sure to deliver supramaximal stimulation. Evoked action currents were estimated offline and superimposed on participant’s X-ray images. Similar to median nerve stimulation, the estimated currents distribution for the ulnar nerve stimulation comprised leading and trailing dipoles which traveled along the BP. Then, the estimated currents propagated into the C7 - Th1 intervertebral foramen. Together with our previous study on magnetoneurogram after median nerve stimulation, we consider magnetoneurogram testing as superior to conventional SEP for analyzing the conductive function of BP because the former enables us to evaluate the conductive function of the nerve from the lateral or medial cord of BP to C5 – Th1 intervertebral foramen after median or ulnar nerve stimulation.