Ultrasound differentiation of axonal and demyelinating neuropathies.

INTRODUCTION: Ultrasound can be used to visualize peripheral nerve abnormality. Our objective in this study was to prove whether nerve ultrasound can differentiate between axonal and demyelinating polyneuropathies (PNPs).

METHODS: Systematic ultrasound measurements of peripheral nerves were performed in 53 patients (25 with demyelinating, 20 with axonal, 8 with mixed neuropathy) and 8 healthy controls. Nerve conduction studies of corresponding nerves were undertaken.

RESULTS: Analysis of variance revealed significant differences between the groups with regard to motor conduction velocity, compound muscle action potential amplitude, and cross-sectional area (CSA) of different nerves at different locations. Receiver operating characteristic curve analysis revealed CSA measurements to be well suited for detection of demyelinating neuropathies, and boundary values of peripheral nerve CSA could be defined.

CONCLUSIONS: Systematic ultrasound CSA measurement in different nerves helped detect demyelination, which is an additional cue in the etiological diagnosis of PNP, along with nerve conduction studies and nerve biopsy.