The diagnosis of peripheral polyneuropathy in children and the differential diagnosis among its various forms often present a challenge, also because electrodiagnostic studies can be painful and sometimes yield inconclusive results. This systematic review examines the role of nerve ultrasound (n-US) in the diagnosis and follow-up of pediatric polyneuropathies. We searched PubMed and Embase from 1975 to April 1, 2025. Included studies assessed patients aged ≤ 18 years with clinically and neurophysiologically confirmed polyneuropathy, providing pediatric-specific qualitative or quantitative n-US findings. Eighteen studies met the inclusion criteria. Six focused on acquired inflammatory polyneuropathies (three on Guillain–Barré Syndrome [GBS], three on Chronic Inflammatory Demyelinating Polyneuropathy [CIDP]), eight on Charcot–Marie–Tooth disease (CMT), two on lysosomal storage disorders, one on Autosomal Recessive Spastic Ataxia of Charlevoix–Saguenay (ARSACS), and one on mixed etiologies. Most (n = 7) were case reports. Cross-sectional area and nerve enlargement (NE) distribution were the main parameters evaluated. Marked, diffuse NE was found in demyelinating CMT and lysosomal disorders; CIDP showed diffuse and multifocal NE; GBS presented mild and proximal NE. No NE was reported in axonal CMT or ARSACS. Few studies assessed echogenicity or fascicular structure; none evaluated vascularization. n-US shows promise in differentiating demyelinating conditions such as CMT, CIDP, GBS, and certain metabolic syndromes in children. However, further age-matched control studies are needed, given that nerve growth and myelination peak between 15 and 17 years. Future research should explore n-US as an early diagnostic, screening, and follow-up tool.

All authors contributed to the study's conception and design, commented on previous versions of the manuscript, and read and approved the final version. Material preparation, data collection, and analysis were performed by S.M. and A.P., who also wrote the first draft of the manuscript.

Not applicable.

Received: 28 July 2025

Accepted: 21 October 2025

Accepted Manuscript online:
27 October 2025

Article published online:
03 November 2025

© 2025. Thieme. All rights reserved.

Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany