Correlation between the etiology of severe hearing loss and endolymphatic hydrops

Purpose This study aimed to investigate correlation between the presence of endolymphatic hydrops(EH) and factors such as causes of hearing loss, patient age, duration of deafness, and results of vestibular function tests. Methods We retrospectively reviewed medical charts of 128 ears of cochlear implantees who were not considered relevant to Meniere's disease. Results When comparing group with genetic variants of GJB2, SLC26A4, LMX1A and other genetic mutation group, the proportion of vestibular EH and cochlear EH found in group with genetic variants of GJB2, SLC26A4, LMX1A was significantly higher than group with other genetic etiology (p < 0.01) or the group with all the other causes of hearing loss (p < 0.01). The rate of vestibular and cochlear EH detection was higher in younger patients (41.5% and 35.4%) than in older patients (25.4% and 20.6%). A higher ratio of vestibular and cochlear EH was observed in patients with a longer duration of deafness (37.5% and 31.3%) than those with a shorter duration of deafness (29.7% and 25.0%). The group with vestibular EH showed a higher incidence of abnormal findings in the caloric test (42.9%) than the group without vestibular EH (28.2%). Conclusion Patients with genetic variants of GJB2, SLC26A4, LMX1A, younger patients, those with longer deaf durations showed a higher prevalence of vestibular and cochlear EH, implying EH appears to be formed as a developmental disorder in association with a certain set of genetic variants, rather than a phenotypic marker as a result of severe to profound hearing loss.