The Neural Mechanisms of Tinnitus: A Perspective From Functional Magnetic Resonance Imaging

Abstract

Tinnitus refers to sound perception in the absence of external sound stimulus. It has become a worldwide problem affecting all age groups especially the elderly. Tinnitus often accompanies hearing loss and some mood disorders like depression and anxiety. The comprehensive adverse effects of tinnitus on people determine the severity of tinnitus. Understanding the mechanisms of tinnitus and related discomfort may be beneficial to the prevention and treatment, and then getting patients out of tinnitus distress. Functional magnetic resonance imaging (fMRI) is a powerful technique for characterizing the intrinsic brain activity and making us better understand the tinnitus neural mechanism. In this article, we review fMRI studies published in recent years on the neuroimaging mechanisms of tinnitus. The results have revealed various neural network alterations in tinnitus patients, including the auditory system, limbic system, default mode network, attention system, and some other areas involved in memory, emotion, attention, and control. Moreover, changes in functional connectivity and neural activity in these networks are related to the perception, persistence, and severity of tinnitus. In summary, the neural mechanism of tinnitus is a complex regulatory mechanism involving multiple networks. Future research is needed to study these neural networks more accurately to refine the tinnitus models.

Pretreatment intranetwork connectivity can predict the outcomes in idiopathic tinnitus patients treated with sound therapy

“…In the present study, we found significantly changed (increased or decreased) intranetwork FC within the AUN, aDMN, LFPN, lVN, DAN, and SN in the EG and/or IG compared with the HC group. As an auditory phenomenon, tinnitus has been repeatedly reported to be associated with alterations in the AUN (or auditory regions; Cai, Li, Yang, & Zhang, 2019; Hu et al, 2021; Husain, 2016; Husain et al, 2011; Lan et al, 2021; Schmidt, Akrofi, Carpenter‐Thompson, & Husain, 2013), which indicates the important role of the AUN in tinnitus generation. As the center of the primary auditory cortex, the STG is also considered to be an important multisensory functional brain region that integrates visual, auditory, and language information (Mtui, Gruener, & Dockery, 2016).…”

Implications of Transcranial Magnetic Stimulation as a Treatment Modality for Tinnitus

“…the auditory cortex (AC), as well as other non-auditory areas of the brain, leading to thi perceived sound [15,16]. There are also ototoxic medications such as aspirin, cisplatin aminoglycosides, and loop diuretics that have been associated with tinnitus [17,18].…”

“…It can be caused by several different underlying conditions that affect a wide range of structures between the ear and the brain itself, leading to variability in clinical manifestations. It has been suggested that damage to structures such as the auditory nerve or hair cells within the cochlea can lead to changes in plasticity that enhance the activity in the auditory cortex (AC), as well as other non-auditory areas of the brain, leading to this 2 of 21 perceived sound [15,16]. There are also ototoxic medications such as aspirin, cisplatin, aminoglycosides, and loop diuretics that have been associated with tinnitus [17,18].…”

Transcranial Electric And Acoustic Stimulation For Tinnitus: Study Protocol For A Randomized Double-Blind Controlled Trial Assessing The Influence of Combined Transcranial Random Noise And Acoustic Stimulation On Tinnitus Loudness And Distress

“…Tinnitus originates in the auditory system, but changes in functional connectivity and neuronal activity of non-auditory systems in uence the perception, persistence and severity of tinnitus (8).…”