Functional differences between tinnitus and tinnitus/hyperacusis patients

In chronic tinnitus, there is both the hypothesis that it is associated with increased central neuronal gain and models that postulate reduced neuronal gain. In our opinion, this is a crucial question for future therapeutic approaches in the treatment of tinnitus and hyperacusis.

The present study included 91 normal hearing subjects with and without tinnitus and with and without hyperacusis. In addition to pure tone and speech audiometry, the audiological examination included ABR measurements, tinnitus and hyperacusis questionnaires.

In addition, fMRT imaging was performed with a 3 Tesla scanner. In addition to resting-state measurements for functional connectivity in auditory, attention and stress-specific brain regions, four different acoustic stimuli (music and chirps in different frequency ranges) were used to investigate activity differences between the groups.

In the tinnitus group without hyperacusis, a reduced and delayed response in brainstem audiometry (ABR wave V - Colliculus inferior/ Lemniscus lateralis) was observed compared to the control group, indicating a reduced neuronal response. The tinnitus+ hyperacusis group, however, showed an increased response in ABR waves III (Nucleus olivaris superior) and V (Colliculus inferior/ Lemniscus lateralis).

The evaluation of the tinnitus questionnaire showed a significantly higher load in the group tinnitus + hyperacusis, whereby especially the emotional and cognitive load as well as the penetrance of the tinnitus were significantly higher than in the tinnitus group without hyperacusis. The fMRI data are still being evaluated.

The results thus support both the hypothesis of increased and reduced central neuronal response in tinnitus; hyperacusis seems to be a decisive factor.

Poster-PDF A-1901.PDF

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Artikel online veröffentlicht:
10. Juni 2020