Aim: To analyze age dependencies in the cross-sectional area (CSA) of the median nerve during early childhood.
Method: A total of 43 participants (32 of whom were children younger than 2 years) were included in this cross-sectional study to analyze the age dependency of the CSA of the median nerve at three locations (wrist, forearm and upper arm) using high-resolution ultrasound images.
Results: A strong and highly significant correlation was found between age and CSA (p < 0.001). When plotted, the relationship followed a logarithmic curve (p < 0.001) with a growth rate that decreases with age. Based on the regression analysis, a temporally similar increase in CSA for all three locations was found. The nerve reaches 70% of its final CSA by 2 years of age at all three locations.
Interpretation: Similar to the nerve conduction speed, the increase in CSA is greatest during the first 2 years of life. Then, the rate gradually and synchronously slows at the proximal and distal locations. Measurement of the CSA in the clinical setting might offer a new method to assess the maturation of the nervous system in infants with minimal interference.
Keywords: Children; Cross-sectional area; High-resolution nerve ultrasound imaging; Median nerve; Nerve conduction velocity; Peripheral nerve system development.
Copyright © 2020 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.