Peripheral nerve and muscle ultrasound in amyotrophic lateral sclerosis

Abstract

Introduction: High-resolution ultrasound has been used to evaluate several neuromuscular conditions, but it has only been used on a limited basis in amyotrophic lateral sclerosis (ALS) patients. It has not been used to assess their peripheral nerves. This study was designed to use neuromuscular ultrasound to investigate nerve cross-sectional area and muscle thickness in ALS.

Methods: Twenty individuals with ALS and 20 matched controls underwent neuromuscular ultrasound to measure the cross-sectional area of their median and sural nerves and the thickness of their biceps/brachialis muscle complex.

Results: The cross-sectional area of the median nerve in the mid-arm was smaller in the ALS group than in controls (10.5 mm(2) vs. 12.7 mm(2) , P = 0.0023), but no difference was seen in the sural nerve (4.5 mm(2) vs. 5.0 mm(2) , P = 0.1927). The ALS group also had thinner biceps/brachialis than controls (2.1 cm vs. 2.9 cm, P = 0.0007).

Conclusions: Neuromuscular ultrasound demonstrates nerve and muscle atrophy in ALS and should be further explored as a disease biomarker.

Copyright © 2011 Wiley Periodicals, Inc.

Figures

Figure 1

Image A demonstrates the transducer position used to visualize the median nerve in the mid-arm and obtain the ultrasound image shown in panel B. The arrow points to the median nerve, and the arrowhead points to the adjacent brachial artery. The “H” is placed over the humerus.

Figure 2

Image A demonstrates the transducer position used to visualize the sural nerve and obtain the ultrasound image shown in panel B. The arrow points to the sural nerve, which is located between two superficial veins.

Figure 3

Image A demonstrates the probe position used to visualize the biceps/brachialis muscle complex shown in panel B. The superficial extent of the muscle and the echogenic reflection from the humerus are marked with plus signs (+).