Ototoxicity from organic solvents assessed by an inner ear test battery.

Objective: This study adopted an inner ear test battery comprising audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP) and caloric tests to assess inner ear function in patients with long term exposure to organic solvents.

Methods: Eighteen patients exposed to organic solvents and another 18 non-exposed controls from the same environment were enrolled in this study. Each subject underwent an inner ear test battery.

Results: The percentages of abnormalities identified by the oVEMP test, cVEMP test, audiometry and caloric test for the exposed group were 85%, 54%, 50% and 33%, respectively, which showed significant differences when compared with the respective 8%, 8%, 6% and 0 for the non-exposed group. Additionally, a significantly declining trend of inner ear deficits from the utricle to the saccule, cochlea, and semicircular canals was noted in the exposed group, but not in the non-exposed group.

Conclusions: Ototoxicity was identified in those exposed to organic solvents, with the sequence of abnormal inner ear function from the utricle to the saccule, cochlea, and semicircular canals.