Does caloric vestibular stimulation modulate tinnitus?

Caloric vestibular stimulation (CVS) has been demonstrated to transiently modulate a variety of cognitive functions. These effects are associated with the brain activation induced by CVS, involving the temporal-parietal cortex, anterior cingulate cortex and insular cortex, which are thought to form a multimodal vestibular cortical network The present study investigated the effect of CVS upon tinnitus. Twenty patients undergoing vestibular function tests for symptoms of imbalance and who reported tinnitus were asked to rate their tinnitus using visual analogue measures of pitch and intensity immediately before and after CVS (H2O at 44 degrees C) in the ear ipsilateral to the tinnitus. One patient was excluded due to test findings indicative of a central vestibular abnormality. The mean VAS pitch (pre-post) changed from 5.65 to 5.28 (95% confidence interval (-0.87, 0.12), p-value 0.13) and the mean change in intensity changed from 5.21 to 4.43 (95% confidence interval (-1.60, 0.04). p-value 0.06). The findings indicate that there is no consistent influence of CVS upon tinnitus, and we propose that perceived pitch and intensity of tinnitus are independent of the multimodal vestibular network that is activated by CVS. Crown Copyright (C) 2011 Published by Elsevier Ireland Ltd. All rights reserved.