Abstract
Tinnitus is a problem that affects a diverse range of people. One common trait amongst tinnitus sufferers is the
presence of hearing loss, which is apparent in over 90% of the cohort. It is postulated that the remainder of tinnitus sufferers have hidden hearing loss in the form of cochlear synaptopathy. The loss of hearing sensation is thought to cause a reduction in the bottom-up excitatory signals of the auditory pathway leading to a change in the frequency of thalamocortical oscillations known as Thalamocortical Dysrhythmia (TCD). The downward shift in oscillatory behaviour, characteristic of TCD, has been recorded experimentally but the underlying mechanisms responsible for TCD in tinnitus subjects cannot be directly observed. This paper investigates these underlying mechanisms by creating a biologically faithful model of the auditory periphery and thalamocortical network, called the central auditory processing (CAP) model. The proposed model replicates tinnitus related activity in the presence of hearing loss and hidden hearing loss in the form of cochlear synaptopathy. The results of this work show that both bottom-up and top-down changes are required in the auditory system for tinnitus related hyperactivity to coexist with TCD, contrary to the theoretical model for TCD. The CAP model provides a novel modelling approach to account for tinnitus related activity with and without hearing loss. Moreover, the results provide additional clarity to the understanding of TCD and tinnitus and provide direction for future approaches to treating tinnitus.
presence of hearing loss, which is apparent in over 90% of the cohort. It is postulated that the remainder of tinnitus sufferers have hidden hearing loss in the form of cochlear synaptopathy. The loss of hearing sensation is thought to cause a reduction in the bottom-up excitatory signals of the auditory pathway leading to a change in the frequency of thalamocortical oscillations known as Thalamocortical Dysrhythmia (TCD). The downward shift in oscillatory behaviour, characteristic of TCD, has been recorded experimentally but the underlying mechanisms responsible for TCD in tinnitus subjects cannot be directly observed. This paper investigates these underlying mechanisms by creating a biologically faithful model of the auditory periphery and thalamocortical network, called the central auditory processing (CAP) model. The proposed model replicates tinnitus related activity in the presence of hearing loss and hidden hearing loss in the form of cochlear synaptopathy. The results of this work show that both bottom-up and top-down changes are required in the auditory system for tinnitus related hyperactivity to coexist with TCD, contrary to the theoretical model for TCD. The CAP model provides a novel modelling approach to account for tinnitus related activity with and without hearing loss. Moreover, the results provide additional clarity to the understanding of TCD and tinnitus and provide direction for future approaches to treating tinnitus.
| Original language | English |
|---|---|
| Article number | 18110464 |
| Pages (from-to) | 1845 - 1857 |
| Number of pages | 13 |
| Journal | IEEE Transactions on Neural Systems and Rehabilitation Engineering |
| Volume | 26 |
| Issue number | 9 |
| Early online date | 6 Aug 2018 |
| DOIs | |
| Publication status | Published (in print/issue) - 30 Sept 2018 |
Keywords
- Tinnitus
- Thalamocortical dysrhythmia
- cochlear synaptopathy
- top-down inhibition
