Clinical Features of Non-Lateralized Tinnitus

Tinnitus: Clinical Insights in Its Pathophysiology-A Perspective

Tinnitus, the perception of sound without a corresponding external sound source, and tinnitus disorder, which is tinnitus with associated suffering, present a multifaceted clinical challenge due to its heterogeneity and its incompletely understood pathophysiology and especially due to the limited therapeutic options. In this narrative review, we give an overview on various clinical aspects of tinnitus including its heterogeneity, contributing factors, comorbidities and therapeutic pathways with a specific emphasis on the implications for its pathophysiology and future research directions. Tinnitus exhibits high perceptual variability between affected individuals (heterogeneity) and within affected individuals (temporal variability). Hearing loss emerges as predominant risk factor and the perceived pitch corresponds to areas of hearing loss, supporting the compensatory response theory. Whereas most people who have tinnitus can live a normal life, in 10-20% tinnitus interferes severely with quality of life. These patients suffer frequently from comorbidities such as anxiety, depression or insomnia, acting as both risk factors and consequences. Accordingly, neuroimaging studies demonstrate shared brain networks between tinnitus and stress-related disorders shedding light on the intricate interplay of mental health and tinnitus. The challenge lies in deciphering causative relationships and shared pathophysiological mechanisms. Stress, external sounds, time of day, head movements, distraction, and sleep quality can impact tinnitus perception. Understanding these factors provides insights into the interplay with autonomic, sensory, motor, and cognitive processes. Counselling and cognitive-behavioural therapy demonstrate efficacy in reducing suffering, supporting the involvement of stress and anxiety-related networks. Hearing improvement, especially through cochlear implants, reduces tinnitus and thus indirectly validates the compensatory nature of tinnitus. Brain stimulation techniques can modulate the suffering of tinnitus, presumably by alteration of stress-related brain networks. Continued research is crucial for unravelling the complexities of tinnitus. Progress in management hinges on decoding diverse manifestations, identifying treatment-responsive subtypes, and advancing targeted therapeutic approaches.

A scoping review of the spatial perception of tinnitus and a guideline for the minimum reporting of tinnitus location

Tinnitus spatial localisation is an essential attribute of tinnitus perception and how it is separated from other ongoing neural activity. A scoping review was undertaken to determine how tinnitus localisation is reported, the role of the perceived spatial location of tinnitus on neurophysiology and if sound presented spatially can change tinnitus perception. Following reading of the full-text articles and including articles from reference lists, 46 articles were included for review. Six themes emerged from the results. 1. Where tinnitus was localised. 2. The effects of tinnitus on localisation. 3. The mechanisms underpinning tinnitus spatial location. 4. Masking. 5. Auditory training. 6. Multisensory training and virtual reality (VR). Tinnitus is much more complex than the often-used description of 'ringing in the ears'. Tinnitus can be heard anywhere in and around the head. Spatial sound presentation and perceptual training approaches may disrupt spatial selective attention to tinnitus and appear as changes in some of the neural networks involved in sound localisation. Where tinnitus is heard is a critical aspect of its perception, but its report, even in studies purporting to study localisation, is too general. A matrix for standardised minimum reporting of tinnitus location is recommended.