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Objective To evaluate the lateral semicircular canal high frequency vestibulo-oculomotor reflex (LSC HF VOR) in children with cochlear implant. Methods 16 children (10 females and 6 males, age range = 5–17 years) receiving a unilateral (n = 12) or a bilateral (n = 4) cochlear implant were included and compared to a control group of 20 age-matched normal-hearing (NH) children. Both implanted and NH children received a vestibular function test battery, including a Vestibulo-Ocular Reflex (VOR) gain assessment by means of a video-Head Impulse Test (vHIT), which represented the main outcome measure. In implanted subjects, vHIT was measured on both sides in the “CI-ON” and “CI-OFF” conditions. Results Overall, no significant LSC HF VOR gain difference was found between CI users and NH peers. In the unilaterally implanted group, the LSC HF VOR gain measured in the “CI-ON” condition was significantly higher than in the “CI-OFF” condition, both in the implanted and in the non-implanted ear. In the bilaterally implanted group there was no such a difference between the two conditions, on either side. Conclusion This is the first study investigating the LSC HF VOR gain in children with unilateral and bilateral CI. The study demonstrates that the LSC HF VOR of bilaterally implanted children is comparable to normal hearing children. [ABSTRACT FROM AUTHOR]

The video head impulse test (vHIT) is a diagnostic tool to examine patients experiencing dizziness by assessing the function of the semicircular canals. vHIT has been widely studied in adults but relatively less so in children. The aim of this study was to evaluate the causes of dizziness and the results of vHIT in children. We also identified factors that affect the vHIT results such as artifacts and technical errors. Retrospective review; Tertiary care center. A total of 39 patients who visited our clinic for dizziness from 2014 to 2017. The gain of vestibulo-ocular reflex, refixation saccades, and artifacts were analyzed using vHIT. We analyzed 691 individual vHIT traces and categorized the artifacts into 8 categories. Twenty-three males and 16 females were included. The mean age was 13.84 ± 2.60 years (range, 7–18). Common causes of dizziness were benign paroxysmal vertigo of childhood (25.6%), vestibular neuritis (20.5%), and vestibular migraine (17.9%). The sensitivity and specificity of vHIT based on the bithermal caloric test results were 40% and 94%, respectively. The analysis of vHIT traces revealed that the children had higher artifact ratios of vHIT than the adults. The main artifacts were high gain and blinking eyes. The vHIT results showed a higher percentage of artifacts in children than in the adults. More careful efforts are required to obtain more accurate results during the test, and it is necessary to check for technical errors while interpreting the results. [ABSTRACT FROM AUTHOR]