RESUMO
Objective: We aimed to evaluate differences in ultrasonographic nerve enlargement sites among typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), distal CIDP, multifocal CIDP and multifocal motor neuropathy (MMN) in a Japanese population. Methods: We retrospectively reviewed medical records and selected 39 patients (14 with typical CIDP, 7 with multifocal CIDP, 4 with distal CIDP, and 14 with MMN) who underwent ultrasonography. Median and ulnar nerve cross-sectional areas (CSAs) were measured at the wrist, forearm, elbow, and upper arm. CSA ratios for each nerve were calculated as: wrist-to-forearm index (WFI)â¯=â¯wrist CSA/forearm CSA; elbow-to-upper arm index (EUI)â¯=â¯elbow CSA/upper arm CSA; and intranerve CSA variability (INCV)â¯=â¯maximal CSA/minimal CSA. Results: Significant differences were observed among typical CIDP, multifocal CIDP, distal CIDP, and MMN in CSA at the forearm and upper arm in the median nerves (pâ¯<â¯0.05). Patients with multifocal CIDP had lower WFI and EUI and higher INCV than the other groups (pâ¯<â¯0.05). Conclusions: Regardless of the untreated period, compared with other CIDP subtypes and MMN, multifocal CIDP showed a focal and marked nerve enlargement in the Japanese population. Significance: Differences in nerve enlargement site may be an underlying feature of multifocal CIDP.