Multiple Modalities of Sensory Gating Are Affected in Decompensated Tinnitus.

Objectives: Sensory gating (SG) is the ability to differentiate novel or salient sensory input from known or irrelevant information. In tinnitus, SG is considered dysfunctional, as the brain fails to inhibit internal auditory neural activity before it reaches conscious perception. As a result, the brain continuously processes the tinnitus signal as if it was a new and relevant stimulus. SG can be assessed with a self-report tool, the Sensory Gating Inventory (SGI).

Design: A prospective questionnaire study was performed in persons with tinnitus (n = 358) and a control group without tinnitus (n = 436). Tinnitus severity was assessed with the tinnitus questionnaire (TQ) and used to split the tinnitus group into subgroups of persons with compensated and decompensated tinnitus. The decompensated tinnitus subgroup consisted of persons suffering from severe tinnitus, while the compensated subgroup consisted of persons with less severe tinnitus. Systematic covariation measures were applied to assess the association between the TQ and the SGI results.

Results: SG was impaired in the domains of Perceptual Modulation, Distractibility, and Vulnerability to Fatigue and Stress as well as in the auditory modality in persons with tinnitus when compared with persons without tinnitus. When the tinnitus group was divided into the subgroups, higher SGI scores on all subscales were prevalent in the decompensated tinnitus subgroup. The results in the compensated tinnitus subgroup were more similar to the control group, except for the auditory modality.

Conclusions: The decompensated tinnitus subgroup showed higher scores on all SGI subscales, which might indicate a more substantial SG impairment. The relation between TQ and the SGI results and the subgrouping of persons with tinnitus can consequently inform and improve future research about the transitional period and the processes that dysregulate when compensated tinnitus turns into decompensated tinnitus.