Compensated Vestibular Dysfunction Post Cochlear Implantation in Children with Sensorineural Hearing Loss: A Prospective Study

Children with sensorineural hearing loss have risk of surgically induced vestibular dysfunction post cochlear implantation due to instrumentation. It is clinically important to estimate the risk of vestibular loss post cochlear implant so the patient can be made fully aware of these risks when considering cochlear implantation. The aim of the study was to identify compensated vestibular dysfunction post cochlear implantation. Vestibular function was evaluated both pre and post CI using monothermal warm air caloric testing. Recordings were made using head band camera on SYNAPSYS Ulmer VNG software. ‘Monothermal caloric asymmetry’ (MCA) was depicted as ‘unilateral weakness’ based on the slow phase velocity of nystagmus. MCA of >15% was taken as evidence of canal paresis. The incidence of compensated vestibular dysfunction post CI surgery was found to be 16.66%. The results were statistically significant (p value 0.02) and indicated worsening of canal paresis indicative of vestibular dysfunction. Children for cochlear implantation should undergo evaluation of their vestibular system pre and post surgery. Caution should be exercised before planning bilateral cochlear implantation in the same sitting.