The use of real-time ultrasound in microneurography

Abstract

The use of microneurography to measure muscle sympathetic nerve activity has provided important insights in human physiology. However, placing microelectrodes into nerves can be challenging, particularly in certain patient populations. In this paper, we describe the use of real-time ultrasound guidance to assist with microneurography, including advantages, disadvantages, and proper training.

Copyright © 2011 Elsevier B.V. All rights reserved.

Figures

Figure 1

Photo showing the placement of probe at the lateral aspect of the lower leg to image the peroneal nerve in cross-section at the fibular head (black dot on skin represents caudal border of the fibular head). It is important that attention be paid to ergonomics, including placement of the ultrasound screen, and that an assistant be available to help with adjustments of the ultrasound machine.

Figure 2

Ultrasound image and drawing of structures of interest of a microelectrode being introduced into the peroneal nerve at the lateral aspect of the leg at the fibular head. The image is rotated 90° counterclockwise so that the lateral aspect of the leg is represented by the top of the screen. A high-frequency (12 MHz) linear probe was used to image the nerve in cross-section and the microelectrode inserted in an in-plane approach. The dots at the center of the image are 0.5 cm marks and the maximum depth is 3.1 cm. The peroneal nerve is a round, echogenic object posterolateral to the fibular head. The microelectrode can be seen entering the nerve from the right side of the image. The insertion point of the microelectrode across the skin cannot be seen in the image.

Figure 3

Ultrasound image and drawing of structures of interest of the peroneal nerve at the posterior aspect of the leg at the popliteal fossa. The image is rotated 180° so that the posterior of the popliteal fossa is represented by the top of the screen. The maximum depth is 2.6 cm. A high-frequency (12 MHz) linear probe was used to image the nerve in cross-section. The peroneal nerve is a round, echogenic object lateral to the tibial nerve and popliteal artery and vein. As the nerve is imaged in a more cephalad location, it joins with the tibial nerve to become the sciatic nerve; caudally it is found more laterally.

Figure 4

Ultrasound image and drawing of structures of interest of the radial nerve at the posterior aspect of the distal humerus proximal to the radial head. The image is rotated approximately 180° so that the posterior aspect of the arm is represented by the top of the screen. The maximum depth is 2.2 cm. A high-frequency (12 MHz) linear probe was used to image the nerve in cross-section. The radial nerve is a small teardrop-shaped, echogenic object adjacent to a collateral artery.

Figure 5

Ultrasound image and drawing of structures of interest of the median nerve at anterior aspect of the arm at the antecubital fossa. The anterior aspect of the arm is represented by the top of the screen. The maximum depth is 2.2 cm. A high-frequency (12 MHz) linear probe was used to image the nerve in cross-section. The median nerve is a round, echogenic object medial to the brachial artery.