Differences in Clinical Characteristics and Brain Activity between Patients with Low- and High-Frequency Tinnitus

Abstract

This study was aimed at delineating and comparing differences in clinical characteristics and brain activity between patients with low- and high-frequency tinnitus (LFT and HFT, respectively) using high-density electroencephalography (EEG). This study enrolled 3217 patients with subjective tinnitus who were divided into LFT (frequency<4000 Hz) and HFT (≥4000 Hz) groups. Data regarding medical history, Tinnitus Handicap Inventory, tinnitus matching, and hearing threshold were collected from all patients. Twenty tinnitus patients and 20 volunteers were subjected to 256-channel EEG, and neurophysiological differences were evaluated using standardized low-resolution brain electromagnetic tomography (sLORETA) source-localized EEG recordings. Significant differences in sex (p<0.001), age (p=0.022), laterality (p<0.001), intensity (p<0.001), tinnitus type (p<0.001), persistent tinnitus (p=0.04), average threshold (p<0.001), and hearing loss (p=0.028) were observed between LFT and HFT groups. The tinnitus pitch only appeared to be correlated with the threshold of the worst hearing loss in the HFT group. Compared with the controls, the LFT group exhibited increased gamma power (p<0.05), predominantly in the posterior cingulate cortex (PCC, BA31), whereas the HFT group had significantly decreased alpha1 power (p<0.05) in the angular gyrus (BA39) and auditory association cortex (BA22). Higher gamma linear connectivity between right BA39 and right BA41 was observed in the HFT group relative to controls (t=3.637, p=0.027). Significant changes associated with increased gamma in the LFT group and decreased alpha1 in the HFT group indicate that tinnitus pitch is crucial for matching between the tinnitus and control groups. Differences of band frequency energy in brain activity levels may contribute to the clinical characteristics and internal tinnitus “spectrum” differences.

Resting-State Electroencephalography and P300 Evidence: Age-Related Vestibular Loss as a Risk Factor Contributes to Cognitive Decline

“…The EEG data preprocessing analysis was performed as described in our previous study [ 38, 39 ]. The EEG data pre-processing analysis was conduct by EEGLAB toolbox and scripts written in MATLAB2014a (The Mathworks, Natick, MA) as described in our previous study.…”

Altered Neurovascular Coupling in Unilateral Pulsatile Tinnitus

“…A PET study also confirmed the increased angular gyrus activity in patients with chronic tinnitus (Song et al, 2012). This may be related to the function of the angular gyrus to participate in the integration of auditory stimuli, memory-related activities, self-awareness, and self-perception (Daselaar et al, 2006;De Ridder et al, 2014;Zhang et al, 2020). Moreover, the angular gyrus is involved in shifting the attention of chronic tinnitus patients from auditory phantom percept to visual cues in Heidelberg neuro-music therapy (Krick et al, 2017).…”

“…Moreover, in the present study, increased CBF and normal ReHo were found in the right angular gyrus, suggesting that the increase in the CBF/ReHo ratio was mainly caused by increases in CBF. Prior studies showed that in patients with unilateral tinnitus, synchronized activity and connectivity within the gamma band were increased in the right angular gyrus as assessed using electroencephalography (Vanneste et al, 2011;Zhang et al, 2020). Chen et al (2014) based on fMRI, found increased low-frequency fluctuations in chronic tinnitus patients, indicating increased neuronal activity in this region (Chen et al, 2014).…”

Objective Recognition of Tinnitus Location Using Electroencephalography Connectivity Features

“…It is known from the literature that low-frequency tinnitus (LFT) is perceived and processed differently from high-frequency tinnitus (HFT) ( Zhang et al, 2020 ). However, in the tinnitus participants recruited in this study, we did not deliberately distinguish between patients with LFT or HFT.…”