Impact of short-term tinnitus treatment on cognitive function and neural synchronization

We aimed to evaluate the impact of short-term tinnitus treatment on cognitive function and identify the effects of various treatment combinations on cognitive and tinnitus outcomes. A non-randomized prospective study was conducted with 32 tinnitus patients at a tertiary university hospital between May 2022 and May 2024. Patients received treatments, including neuromodulation, diuretics, gabapentin, selective serotonin reuptake inhibitors (SSRI), anxiolytics, muscle relaxants, hearing aids, and counseling. Cognitive function and tinnitus distress were assessed using the Mini-Mental State Examination (MMSE) and Tinnitus Handicap Inventory (THI) at baseline and 1 month after treatment. Quantitative electroencephalogram (qEEG) recordings were analyzed to evaluate changes in neural synchronization using phase-locking value (PLV). Strong correlations were also observed between baseline MMSE and changes in MMSE post-treatment (r = -0.796, p < 0.01) and between tinnitus loudness perception and changes in MMSE (r = 0.458, p < 0.01). After Bonferroni correction, muscle relaxants (p = 0.017) and neuromodulation (p = 0.007) showed significant negative effects on cognitive function, while anxiolytics demonstrated a tendency for negative effects (p = 0.052). Additionally, neither baseline tinnitus loudness nor changes in loudness perception (ΔVAS for loudness) were significantly correlated with ΔTHI after Bonferroni correction (p > 0.05). qEEG analysis showed increased PLV in prefrontal-limbic and parietal-occipital connections in patients with improved THI as well as increased PLV in temporal-limbic connections in patients with improved MMSE scores, indicating enhanced neural synchronization and cognitive resource reorganization. These findings underscore the need for careful consideration of cognitive effects when selecting tinnitus treatments and highlight the importance of targeted multimodal interventions to address both tinnitus distress and cognitive function.