Nerve enlargement differs among chronic inflammatory demyelinating polyradiculoneuropathy subtypes and multifocal motor neuropathy

Masaaki Yoshikawa; Kenji Sekiguchi; Hirotomo Suehiro; Shunsuke Watanabe; Yoshikatsu Noda; Hideo Hara; Riki Matsumoto

doi:10.1016/j.cnp.2023.10.002

Nerve enlargement differs among chronic inflammatory demyelinating polyradiculoneuropathy subtypes and multifocal motor neuropathy

Clin Neurophysiol Pract. 2023 Nov 22:8:228-234. doi: 10.1016/j.cnp.2023.10.002. eCollection 2023.

Authors

Masaaki Yoshikawa^{1

2}, Kenji Sekiguchi¹, Hirotomo Suehiro¹, Shunsuke Watanabe¹, Yoshikatsu Noda¹, Hideo Hara^{2

3}, Riki Matsumoto¹

Affiliations

¹ Division of Neurology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
² Division of Neurology, Department of Internal Medicine, Saga University Faculty of Medicine, 5-1-1 Nabeshima-cho, Saga 849-8501, Japan.
³ Fukuoka International University of Health and Welfare, 3-6-40 Momochihama, Sawara-ku, Fukuoka 814-0001, Japan.

Abstract

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) = wrist CSA/forearm CSA; elbow-to-upper arm index (EUI) = elbow CSA/upper arm CSA; and intranerve CSA variability (INCV) = 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 (p < 0.05). Patients with multifocal CIDP had lower WFI and EUI and higher INCV than the other groups (p < 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.

Keywords: Chronic inflammatory demyelinating polyradiculoneuropathy; Intranerve cross-sectional area variability; Multifocal motor neuropathy; Nerve cross-sectional area; Nerve ultrasound.