Subjective and objective vestibular changes that occur following paediatric cochlear implantation: systematic review and meta-analysis

Abstract

Objective Cochlear implantation can result in post-operative vestibular dysfunction of unknown clinical significance. The objective of this study was to characterize the presence, magnitude, and clinical significance of vestibular dysfunction that occurs after pediatric cochlear implantation. Data sources The databases Embase, Medline (OvidSP), and PubMed were used. Only articles published in English were included. Grey literature and unpublished sources were also reviewed. Study selection Articles published from 1980 until the present which documented pre-operative and post-operative vestibular testing on children under the age of 18 were used. Data extraction Parameters that were assessed included number of patients, pre- and post-operative vestibular-evoked myogenic potentials (VEMPs), head impulse testing (HIT), calorics, and posturography, timing of pre- and post-operative testing, symptomatology, and other demographic data such as etiology of the hearing loss. Data synthesis Ten articles were included. Relative risk values evaluating the effect of cochlear implantation on vestibular function were calculated for VEMPs and caloric testing due to the availability of published data. I 2 values were calculated and 95% confidence intervals were reported. Separate analyses were conducted for each individual study and a pooled analysis was conducted to yield an overall relative risk. Assessment on risk of bias in individual studies and overall was performed. Conclusion Pediatric cochlear implantation is associated with a statistically significant decrease in VEMP responses post-operatively (RR 1.8, p < 0.001, I 2 91.86, 95%CI 1.57–2.02). Similar results are not seen in caloric testing. Insufficient data is available for analysis of HIT and posturography. Further studies are necessary to determine the effect of cochlear implantation on objective vestibular measures post-operatively and whether any changes seen are clinically relevant in this population.

Vestibular Infant Screening (VIS)–Flanders: results after 1.5 years of vestibular screening in hearing-impaired children

“…The rationale for vestibular screening at the age of 6 months is the following: (1) the hearing loss is confirmed in the majority of the children by that age 39 , (2) gross motor milestones can already give an idea of the child's vestibular function 3 , and (3) most children have already developed sufficient head stabilisation due to sufficient development and control of neck musculature, which is fundamental for reliable cVEMP assessment 40 . In addition, possible cochlear implant surgery which entails a potential risk for vestibular (mainly otolith) deficits 31,[41][42][43] , has not been performed yet 44 . As a result, the vestibular (mainly saccular) status is known before some of these children will undergo cochlear implant surgery.…”

Vestibular dysfunction after cochlear and auditory brainstem implantation: Madras ENT Research Foundation experience

“…3 Cochlear implantation may affect vestibular function through direct current spread from the cochlea to the vestibular system. 4 Ito reported dizziness in 2.5% of patients when the CI was activated. 5 After CI surgery, otolithic organs and canal function can be compromised, leading to potential clinical manifestations such as postoperative imbalance, vertigo, and falls.…”

“…In children undergoing bilateral implantation, bilateral vestibular dysfunction after CI may be a concern. 4 CI can potentially result in disruption of saccular function in pediatric patients. The estimated prevalence of peripheral vestibular dysfunction after CI is around 20% for adults and 10% for children.…”

“…Regardless of objective results, no evidence for subjective symptoms of dizziness occurring in the pediatric population after cochlear implantation was reported. 4 The true incidence of injury after unilateral CI surgery may be masked by central compensation of vestibular hypofunction. The worse balancing ear should be implanted.…”

“…9 The saccule and the lateral semi-circular canal have been considered the vestibular organs that are more likely to be affected by Handzel et al 1 Mechanisms for vestibular dysfunction include direct trauma related to insertion of the electrode, intra-operative perilymphatic fluid leakage, electrical stimulation of the otolithic organs, and foreign body labyrinthitis. 4 Approximately 10-20% of patients were reported to have developed BPPV post cochlear implantation. 10 Meniere's after CI may occur due to cochlear hydrops accompanied by saccular collapse which may cause attacks of vertigo of delayed onset, similar to Meniere's syndrome.…”