Synaptic transmission in brainstem auditory structures in patients with tinnitus treated with nimodipine: a randomized clinical trial.

Purpose: To evaluate the synaptic transmission in brainstem auditory structures in patients with subjective chronic bilateral tinnitus treated with nimodipine. Methods: A randomized triple-blind controlled clinical trial, which selected 40 patients allocated equally and randomly in intervention and control groups. At first, the Brainstem Evoked Response Audiometry (BERA) and the questionnaires Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS) for loudness and annoyance for each ear were applied with the participants. The participants were advised to take one pill per day during 30 days of nimodipine or placebo, which were previously manipulated in pills of identic appearance and delivered to the participants. After this period the participants were submitted to a new BERA and questionaries THI and VAS. Results: The study counted with 38 participants, from which 18 belonged to control group and 20 in the intervention, since two participants of the control group were excluded due to the discontinuity of taken pills. The comparative analysis between the two BERA exams showed significant difference for wave III and V latencies, as well for the interpeak intervals I-III and I-V, with higher values at the second exam, only for the intervention group. The comparative analysis of THI and VAS questionnaires did not show significant difference in both groups. Conclusion: Nimodipine in a dose of 30 milligrams per day during 30 days in individuals with tinnitus has evidence to alter synaptic transmission in brainstem structures. In contrast, there was no significant improvement of tinnitus complaints through THI and VAS questionnaires. [ABSTRACT FROM AUTHOR]