Assessment of Otolith Function with Subjective Visual Vertical Test in Sensorineural Hearing Loss: An Analytical Cross - Sectional Study

The inner ear is responsible for balance and auditory function. Sensorineural hearing loss (SNHL) affects auditory function across various age groups. Vestibular apparatus, particularly the otolith organ can also be affected in cases of SNHL because of the close proximity of the otolith organs with the cochlea inside the bony labyrinth. The otolith organs can be assessed with Subjective Visual vertical test (SVV), which is a simple, rapid, non-invasive test with high sensitivity and specificity. Present study was conducted with the objective to compare the SVV parameters between normal and SNHL patients and to correlate between the degree of tilt in SVV with severity of SNHL. A convenient sample size of 60 was taken of which 30 were control and 30 were SNHL patients. PTA and SVV were performed on both groups and results were analysed in IBM SPSS version 26. Age stratified analysis between the control group and SNHL group for the age group 20-40 years and for > 40 years revealed a significant statistical difference in the average static SVV (P = 0.019 and P = 0.009 for age group 20-40 years and > 40 years respectively) and dynamic anti clockwise SVV (P = 0.024 and P = 0.031 for age group 20-40 years, and > 40 years respectively) between the control group and the SNHL group. Correlational analysis also shows a moderate correlation between the bone conduction threshold and the various SVV parameters. Statistical difference of SVV parameters between the two groups suggests a possible early involvement of the otolith organ in SNHL. As such the utility of SVV as an early marker for otolith dysfunction needs to be further explored. It may be worthwhile to follow up the patients of SNHL longitudinally and assess the otolith function with SVV at periodic intervals to identify any progression.