Alterations of brain activity and functional connectivity in transition from acute to chronic tinnitus

Abstract

The objective of this study was to investigate alterations to brain activity and functional connectivity in patients with tinnitus, exploring neural features in the transition from acute to chronic phantom perception. Twenty-four patients with acute tinnitus, 23 patients with chronic tinnitus, and 32 healthy controls were recruited. Highdensity electroencephalography (EEG) was used to explore changes in brain areas and functional connectivity in different groups. When compared with healthy subjects, acute tinnitus patients had a significant reduction in superior frontal cortex activity across all frequency bands, whereas chronic tinnitus patients had a significant reduction in the superior frontal cortex at beta 3 and gamma frequency bands as well as a significant increase in the inferior frontal cortex at delta-band and superior temporal cortex at alpha 1 frequency band. When compared to the chronic tinnitus group, the acute tinnitus group activity was significantly increased in the middle frontal and parietal gyrus at the gamma-band. Functional connectivity analysis showed that the chronic tinnitus group had increased connections between the parahippocampus gyrus, posterior cingulate cortex, and precuneus when compared with the healthy group. Alterations of local brain activity and connections between the parahippocampus gyrus and other nonauditory areas appeared in the transition from acute to chronic tinnitus. This indicates that the appearance and development † Liping Lan and Jiahong Li contributed equally to this work.

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).…”

The balance between Bayesian inference and default mode determines the generation of tinnitus from decreased auditory input: A volume entropy‐based study

“…a part of the central executive network (CEN) that is related to activity inhibition, emotion, and working memory (Lan et al, 2021), the modulatory role of the SN with regard to the function of the CEN may have resulted in better perception of the parahippocampal memory-based tinnitus. Salience is also related to the subjective value that the brain (sgACC) ascribes to missing information, irrespective of the stimulus type, as demonstrated by a meta-analysis (Clithero & Rangel, 2014).…”

“…Therefore, we speculate that, in our HL‐T group, decreased peripheral auditory input may have been regarded as a behaviorally salient stimulus by the insula, which may promote the generation of tinnitus by pulling auditory memories from the (para)hippocampus and aforementioned prefrontal areas. Also, as the IFG is a part of the central executive network (CEN) that is related to activity inhibition, emotion, and working memory (Lan et al, 2021 ), the modulatory role of the SN with regard to the function of the CEN may have resulted in better perception of the parahippocampal memory‐based tinnitus. Salience is also related to the subjective value that the brain (sgACC) ascribes to missing information, irrespective of the stimulus type, as demonstrated by a meta‐analysis (Clithero & Rangel, 2014 ).…”

“…Future studies controlled for the sex ratio should be performed to check the reproducibility of the current study. Third, future studies subdividing the HL‐T group into low‐ and high‐distressed tinnitus or acute‐ or chronic tinnitus may give us further information on other culprit brain areas of tinnitus generation such as the posterior cingulate cortex (PCC), based on previous qEEG studies showing connectivity changes in the PCC according to the chronicity of tinnitus (Lan et al, 2021 ) or the level of tinnitus‐related distress (Vanneste & De Ridder, 2015b ).…”

Cerebral Blood Flow Difference Between Acute and Chronic Tinnitus Perception: A Perfusion Functional Magnetic Resonance Imaging Study

“…A latest EEG study compared acute and chronic tinnitus, which found differences in neural activity and connectivity in many regions. It was found that a non-auditory brain region, especially parahippocampus gyrus, plays a key role in the transition from acute to chronic tinnitus ( Lan et al, 2021 ). Therefore, we suggest that chronization of tinnitus is a complex mechanism involving multiple networks.…”