Peripheral nerve ultrasound scoring systems: benchmarking and comparative analysis

Ultrasound of the nerves is an additive diagnostic tool to evaluate polyneuropathy. Recently, the need for standardized scoring systems has widely been discussed; different scores are described so far. Therefore, 327 patients with polyneuropathy were analyzed by ultrasound in our laboratory. Consequently, several ultrasound scoring tools were applied, i.e., the nerve pattern classification according to Padua et al. in all patients with CIDP and variants, the Bochum ultrasound score (BUS) and the neuritis ultrasound protocol in immune-mediated neuritis, the ultrasound pattern sum score, the homogeneity score, and the nerve enlargement distribution score in all neuropathies if possible. For all scores good accuracy was found. Most patients with CIDP revealed hypoechoic enlarged nerves (Class 1), the BUS/NUP was useful to identify GBS (sensitivity >85%), MMN (100%) and CIDP (>70%), while the UPSS showed high sensitivity and positive/negative predictive values (N/PPV) in the diagnosis of GBS (>70%), CIDP (>85%) and axonal non-inflammatory neuropathies (>90%). Homogeneous nerves were found in most CMT1 patients (66.7%), while immune-mediated neuropathies mostly show regional nerve enlargement. The HS was suitable to identify CMT patients with an HS ≥5 points. All scores were easily applicable with high accuracy. The former-reported results could be similarly confirmed. However, all sores have some incompleteness concerning unselected polyneuropathy population, particularly rare and focal types. Scoring systems are useful and easily applicable. They show high accuracy in certain neuropathies, but also offer some gaps and can, therefore, only be used in addition to standard diagnostic routines such as electrophysiology.