Olivocochlear efferent reflex strength in vestibular schwannoma patients

Olivocochlear efferent reflex strength in vestibular schwannoma patients. Problem/objective: The olivocochlear reflex strength can be measured using contralateral acoustic stimulation (CAS) of transient evoked otoacoustic emissions (TEAOEs). The efferent suppression (ES) thus reflects the functional intactness of the efferent auditory system. In patients with unilateral vestibular schwannoma (VS), the results of ES are unclear. Methods: This cross-sectional study evaluated click and noise intensity conditions for measuring ES using CAS of TEOAEs in nine patients with unilateral VS and in gender-, age- and ear side-matched control subjects. Results: Two optimal click and noise intensity level combinations were identified. This pilot study compared the amount of ES between tumour and non-tumour ears versus control ears in patients with unilateral VS,but there were no statistically significant differences. Conclusion: Future studies should include a larger population of unilateral VS patients with different grades of hearing loss