Sonographic Characterization of Immune‐Mediated Peripheral Neuropathy

Background and Purpose Whether neuromuscular ultrasound (NMUS) can help differentiate between different types of immune‐mediated neuropathy remains unclear. This study aims to investigate the sonographic features of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) and other immune‐mediated neuropathies. Methods This exploratory study was performed in our center between August 2022 and June 2025. Thirty‐one patients were enrolled after providing written consent. Twelve patients met the criteria for CIDP, and 19 were diagnosed with immune‐mediated demyelinating neuropathy, which is not CIDP; 12 multifocal motor neuropathy (MMN), 4 anti‐MAG (DADS) neuropathy, and others. CIDP diagnosis was established according to the EAN/PNS 2021 guidelines. Results CIDP group had higher cross‐sectional area (CSA) values, compared to the non‐CIDP immune neuropathy group. This was demonstrated in two nerve segments reaching statistical significance (median nerve in the forearm and ulnar nerve in the groove, p < 0.05) and in the overall average of the value ‘measured CSA divided by expected normal CSA’; 131% versus 102%, p = 0.004. Similar results were found between CIDP versus MMN (with no other non‐CIDP disorders). Honeycomb architecture was more distorted in the non‐CIDP immune neuropathy group, whereas echogenicity was similar. Conclusions We provided a sonographic characterization for CIDP and non‐CIDP cases, highlighting neuroimaging parameters that differentiate between the two groups, such as CSA. This study enriches the existing information about the utility of NMUS and improves our ability to differentiate between CIDP and other immune‐mediated neuropathies.