Assessment of functional development of the otolithic system in growing children: a review

Abstract

Objectives: Although the caloric test, rotational test, and posturography have been used to investigate balance function conventionally, and they are older than tests of otolithic organs, yet it seems that most clinicians are less familiar with the development of otolithic (saccular and utricular) function in children. This study reviewed the electrophysiological testing used to assess the functional development of the otolithic system in growing children.

Methods: Based on the literature, studies of cervical vestibular-evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) tests in children ranging from newborns, small children to adolescents were reviewed. Papers concerning foam posturography in children were also included.

Results: The cVEMPs can be elicited in newborns at day 5, whereas the oVEMPs are absent in neonatal period. When children grow to 2 years old, the oVEMPs can be induced with eyes closed condition, while the oVEMPs with eyes up condition can be elicited in children aged >3 years old, with the characteristic parameters similar to adult levels. In contrast with cVEMPs, it is until the neck length >15.3cm (aldolesence), one need not account for neck length in evaluating cVEMP latency. Additionally, foam posturography indicated by the Romberg quotient of the sway velocity/area on foam pad is considered to reflect the otolithic function, which reached adult levels when the children at 12 years old.

Conclusions: For the functional development of the otolithic system in growing children to approach adult levels, the earliest occurrence is the oVEMP test, followed by the foam posturography, and cVEMP test.

Keywords: Cervical vestibular-evoked myogenic potential; Foam posturography; Functional development; Ocular vestibular-evoked myogenic potential; Saccule; Utricle.