Influence of Cochlear Implantation on Balance Function in Pediatrics

Patients with profound Sensorineural Hearing Loss (SNHL) are susceptible to vestibular disturbances following Cochlear Implant (CI) surgery. This study aimed to evaluate vestibular dysfunctions following unilateral CI in the congenitally deaf children.

This was a cross-sectional study conducted on 24 children (mean age: 10.56 ± 5.49 years old) who underwent unilateral CI and 24 age-matched controls (mean age: 11.13 ± 6.21 years old). Vestibular functions were assessed by Vestibular Evoked Myogenic Potential (VEMP) and Computerized Dynamic Posturography (CDP). The VEMP test was performed for otolith's function (especially saccule) evaluation. Sensory Organization Test (SOT) protocol of CDP was also utilized to differentiate the role of various sensory systems contributing to postural stability. In addition, total equilibrium score was calculated. The variables were comparatively assessed between the two groups.

The mean p13-n23 amplitude in the CI users was significantly lower than the controls (p<0.05). However, the two groups showed no significant difference in cVEMP latency values (p>0.05). The SOT analysis revealed that 45.83% (11/24) of the CI subjects had some kind of sensory abnormalities: 7 cases (29.17%) vestibular, 2 cases (8.33%) visual, 2 cases (8.33%) vestibular and somatosensory involvements. Furthermore, total equilibrium score was significantly reduced in implanted group than the controls (p<0.001). At least, 70.59% (12/24) CI patients showed abnormal values in the CDP or cVEMP examinations.

This study shows functional vestibular impairments in children who underwent CI. These patients showed significantly increased postural instability which was more evident in dynamic conditions. These findings provide the basis for better pre-operative counseling and postoperative vestibular rehabilitation to CI recipients.