Supplementary Material for: Effect of Vestibular Dysfunction on the Development of Gross Motor Function in Children with Profound Hearing Loss

<b><i>Objective:</i></b> To evaluate the function of the superior and inferior vestibular nerve systems in children with profound sensorineural hearing loss, and to assess the influence of dysfunction of each vestibular nerve system on the development of gross motor function. <b><i>Study Design:</i></b> Retrospective study. <b><i>Setting:</i></b> A tertiary referral center. <b><i>Methods:</i></b> Eighty-nine children (age range: 20–97 months) with profound sensorineural hearing loss who were due to undergo cochlear implant surgery were recruited. Function of the superior vestibular nerve system was evaluated by the damped rotation test and the caloric test, whereas functions of the inferior vestibular nerve systems were evaluated by the vestibular evoked myogenic potential (VEMP) test. Gross motor development was assessed using the age of acquisition of head control and independent walking. <b><i>Results:</i></b> Among the children able to complete the vestibular function tests, abnormalities were found in 20% (16 of 84 children) in the damped rotation test, 41% (31 of 75 children) in the caloric test and 42% (26 of 62 children) in the VEMP test. Children who showed abnormal responses in the vestibular function tests showed significantly delayed acquisition of head control (p < 0.05) and independent walking (p < 0.05) in comparison with children with normal responses. The children who showed abnormal responses in all 3 vestibular tests showed the greatest delay in acquisition of gross motor function in comparison with the other groups. <b><i>Conclusions:</i></b> Children with profound hearing loss tend to have dysfunction in the superior as well as the inferior vestibular nerve systems. Both the superior and inferior vestibular nerve systems are important for the development of gross motor function in children.