Effects of Noise Exposure on Video Ocular Counter Roll Measurements.

PURPOSE: The purpose of this study was to evaluate the effect of noise exposure on otolith function measures of video ocular counter roll (vOCR), ocular vestibular evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and subjective visual vertical (SVV). Additionally, this study compared the vOCR results with other otolith function measures: cVEMP, oVEMP, and SVV.

METHOD: This was a cross-sectional, between-group prospective study that compared otolith function tests between noise exposure groups. Thirty-three adults between the ages of 40-60 years with no middle ear pathology, history of balance disorder, neurologic pathology, systemic diseases, or receiving ototoxic medications were included in the study. Group 1 included 17 adults (34 ears) with low-risk noise exposure, and Group 2 included 16 adults (32 ears) with high-risk noise exposure. Independent samples t tests were used to assess group mean differences for dependent variables. The independent variable was group with two levels (low risk and high risk). The dependent variables were Noise Exposure Structured Interview (NESI) score, vOCR torsion, cVEMP amplitude, oVEMP amplitude, and SVV angle. Additional analyses were completed using Pearson correlation to evaluate the relationship of vOCR to the other otolith function tests and NESI score to the otolith function tests.

RESULTS

The results indicated significantly decreased vOCR torsion, cVEMP amplitude, and oVEMP amplitude in individuals with high-risk noise exposure compared with those in the low-risk group. Significant correlations were found for NESI scores as well as vOCR and oVEMP measures.

CONCLUSIONS

This study describes the concomitant degeneration of the auditory and vestibular systems from noise exposure affecting otolith function, as measured by audiologic testing and otolith testing. vOCR appears to be sensitive to this degeneration, indicating that vOCR could be used as a vestibular screening measure for patients with noise exposure and/or suspected utricle dysfunction.