Objective Assessment of Otolith and SCCs Functions in Individuals with Severe to Profound Hearing Loss

Abstract

This study was designed to objectively assess the functioning of otolith (saccule and utricle) and three semicircular canals in individual with severe to profound sensorineural hearing loss using cVEMP, oVEMP and vHIT respectively. Twenty adult participants (40 ears) having severe to profound hearing loss ranging in age from 15-40 years in group I. Group-II consisted of 20 adult participants (40 ears) in the age range from 15-40 years with normal hearing sensitivity. All the participants underwent a detailed case history, pure tone audiometry, immitance and reflexometry, cVEMP, oVEMP and vHIT tests. cVEMP was present in 90% and 75% in right and left ear of individual with severe to profound hearing loss respectively. No significant difference between the latencies of both the groups whereas significant difference was found between the p1-n1 amplitude complexes of both the group in which smaller amplitude was found for individual with severe to profound hearing loss. oVEMP was present in 55% and 60% in right and left ear of individual with severe to profound hearing loss respectively. No significant difference between the latencies of n1, p1 and n2 of both the groups whereas significant difference was found for the amplitude complex of p1-n1 and p1-n2 of both the groups. Mean VOR gain values for right and left horizontal canals, right anterior and left posterior canal for individual with hearing impaired is lesser than the individual with normal hearing. There were significant differences between group 1 and group 2 for VOR gain for right horizontal canal and left horizontal canal whereas significant difference was showed in right posterior canal, left anterior canal, right anterior canal and left posterior canal. No association found between cVEMP, oVEMP and different planes of vHIT of right ear. To conclude, vestibular abnormality was seen for both otolith organs (saccule and utricle) and semi circular canals in individual with severe to profound hearing loss. Therefore, vestibular tests should be included along with various audiological tests in the diagnostic protocol for the assessment of individual with severe to profound sensorineural hearing loss.