Tinnitus as a network problem – plasticity in anatomical and functional connectivity

• Applicant: Dr. Stephanie Rosemann
• Subject Area: Human Cognitive and Systems Neuroscience
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 432344335

Tinnitus is the phantom perception of sound when there is no external auditory input. This sound is mostly perceived as a whistling, buzzing or hissing in the ear. Chronic tinnitus – the permanent phantom perception – currently affects 10-20% of the population but no reliable treatment has been found so far. One of the peripheral causes for tinnitus is hearing loss due to loud noise exposure or age-related degeneration, leading to plastic changes in auditory and non-auditory brain regions. Rauschecker and colleagues suggested a frontostriatal gating model of tinnitus, which supposes that the breakdown of a so-called noise-cancelling system involving thalamic and limbic brain regions leads to chronic tinnitus. However, the exact underlying mechanisms are not fully understood yet, mainly because of the heterogeneity of previous studies that differ in sample size, appropriate selection of control group and analysis methods leading to inconsistent findings. Hence, in the proposed research project, I aim to test the frontostriatal gating model of tinnitus by investigating neuroplastic anatomical and functional changes in tinnitus patients compared to control participants matched for age and hearing loss. The focus lies on connectivity measures to determine not only neural alterations within brain regions but also (changes of) anatomical and functional connections between those brain areas. To that end, functional magnetic resonance imaging is used, complementing previous work with new measurement techniques as well as analysis methods (e.g., effective connectivity or track-weighted functional connectivity). In addition, these measures will be related to cognitive impairments and tinnitus distress (e.g., depression) that often come with the chronic tinnitus sensation. Thus, the project will not only extend my own methodological skills but also advance knowledge about neural mechanisms in tinnitus. I hereby specifically assess the interplay of tinnitus, tinnitus distress, hearing loss and cognitive impairment with respect to neural alterations. Within this research proposal, I expect to better understand both the mechanisms of the causal pathological reorganization leading to chronic tinnitus and the neural disruptions that may serve as a biomarker for tinnitus in the future.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Josef Rauschecker