Postural Control and Gait Performance in Pre-lingual Cochlear Implant Users Related with Vestibular Function and Auditory Input

Background: The role of auditory information and vestibular input in the control of gait and balance is currently not clear.

Objective: This study assesses the relationship between postural control and gait performance with auditory input and remaining vestibular function in a sample of pre-lingual cochlear implanted children.

Methods: Postural control. Posturography was performed in a sample of 14 pre-lingual cochlear implant users (CIU), 8 to 16 years old, classified into two groups, 1) with normal vestibular function (IVN), and 2) with vestibular hypofunction (IVH). Both conditions were analyzed with the cochlear implant (CI) turned on and off and each group was divided into younger (<12) and older than 12 years old (>12). The body center of pressure was recorded and analyzed computing the total energy consumption of this signal (ECCOP). Gait velocity (GV), using a 10-meter test, was measured by means of three inertial sensors in two sensory conditions, (A) cochlear implant turned on with environmental noise (EN), and (B) cochlear implant turned off (CI-OFF). The two tests were compared with a control group of normal hearing children (CG) of the same age range. Wilcoxon Ranked and Kruskal Wallis tests were used for the statistical analysis.

Results: Postural Control. CIU with IVH <12, showed higher ECCOP than the others groups p=12 acquired normal values in all the sensory conditions. No differences were found with the implant turned on or off. Gait Performance. The CIU implanted after three years of age have slower GV than the CG and than the CIU implanted before this age, p=0.02. They improve gait with the CI-OFF, p=0.02.

Conclusions: These data suggest that vestibular hypofunction has different impact according with age in postural strategies, while auditory input is more relevant in gait performance. Consideration about neurodevelopment and adaptation is discussed.