[Nerve ultrasound is useful for the diagnosis of neuromuscular diseases]

High-resolution ultrasound allowed for more detailed morphological assessment peripheral nerves and muscles. It is important to elucidate ultrasound features of peripheral nerves or muscles in various neuromuscular diseases because ultrasound is a widely used, non-invasive and easily accessible diagnostic tool. We attempted to demonstrate characteristic findings of nerve ultrasound in patients with Charcot-Marie-Tooth disease (CMT), Amyotrophic lateral sclerosis (ALS), and Cervical radiculopathy. In patients with CMT1A, cross sectional areas (CSAs) of all the nerves we examined were significantly larger than those in normal controls. Additionally, median nerve CSA had positive correlation with CMT neuropathy score, and negative correlation with nerve conduction velocity. In patients with ALS, increased CSA forearm/upper arm ratio of the median nerve was a characteristic finding to support the diagnosis. In patients with cervical radiculopathy, we could observe that decreased CSA and diameter of the nerve root corresponding to the findings of MRI and electromyography. These results demonstrate that the combination of electrophysiological study, diagnostic imaging, and nerve ultrasound could lead to accurate diagnosis of various neuromuscular diseases.