Peripheral nerve and muscle ultrasound in amyotrophic lateral sclerosis

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.