Charcot–Marie–Tooth (CMT) disease is the most common inherited peripheral neuropathy. Limited information on imaging in neuromuscular conditions is available and further less in Hispanic patients. Sonographic examination has been used to describe the pathology of the nerves in patients with CMT. The purpose of this study is to describe imaging of the nerves and muscles that affect ambulation using sonographic and evaluate their association with walking speed.

Twenty-one patients previously diagnosed with a demyelinating form of CMT via genetic testing and/or electrodiagnostic study with family history of CMT were evaluated. Ultrasound (US) measurements of the common peroneal nerve (CPN), cross-sectional area (CSA) and anterior tibialis muscle (ATM) depth were performed. CPN compound motor action potential (CMAP) amplitude recording at the ATM was recorded. Later a 10-meter walk test and a Stair Climb test were performed.

US evaluation showed significant increase in median and CPN CSA average when compared to reference data. Although not statistically significance there was a positive association between CMAP amplitude recording at the ATM and ATM depth in axial plane or size and ambulation velocity w/o AFO. This could be related to the fact that CPN with less pathology nerve conduction should be able to adequately supply the ATM, therefore better amplitude is obtained and less muscle atrophy is found. The negative association was found between CPN CSA and ambulation velocity w/o AFO not statistically significant. As the CPN increases in size, ambulation dysfunction is further observed in this population.

To our knowledge no prior study has described the CPN and ATM with US, which are important components for ambulation in CMT. US is a sensitive and relatively accessible tools for evaluating this population. Future correlation of US findings and functional test is a potential field of research for future projects.