Altered Brain Activity and Functional Connectivity in Unilateral Sudden Sensorineural Hearing Loss

Abstract

Background. Sudden sensorineural hearing loss (SSNHL) is an otologic emergency and could lead to social difficulties and mental disorders in some patients. Although many studies have analyzed altered brain function in populations with hearing loss, little information is available about patients with idiopathic SSNHL. This study is aimed at investigating brain functional changes in SSNHL via functional magnetic resonance imaging (fMRI). Methods. Thirty-six patients with SSNHL and thirty well-matched normal hearing individuals underwent resting-state fMRI. Amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and functional connectivity (FC) values were calculated. Results. In the SSNHL patients, ALFF and fALFF were significantly increased in the bilateral putamen but decreased in the right calcarine cortex, right middle temporal gyrus (MTG), and right precentral gyrus. Widespread increases in FC were observed between brain regions, mainly including the bilateral auditory cortex, bilateral visual cortex, left striatum, left angular gyrus (AG), bilateral precuneus, and bilateral limbic lobes in patients with SSNHL. No decreased FC was observed. Conclusion. SSNHL causes functional alterations in brain regions, mainly in the striatum, auditory cortex, visual cortex, MTG, AG, precuneus, and limbic lobes within the acute period of hearing loss.

Aberrant Functional Network of Small-World in Sudden Sensorineural Hearing Loss With Tinnitus

“…In contrast, Xu et al (2016) detected enhanced Cp and weakened Lp in unilateral SNHL. Chen et al found that tinnitus patients have increased global efficiency, local efficiency, and cluster coefficient, indicating generally heightened connectivity of the network, which was consistent with the increased global efficiency of our study ( Chen et al, 2020 ). These discrepancies might result from (1) various kinds of hearing loss, such as side, duration, and severity; (2) different nodes of network construction and our study chose 90 nodes from the AAL atlas; (3) differences in accompanied symptoms, such as tinnitus and vertigo.…”

Cerebral Blood Flow Pattern Changes in Unilateral Sudden Sensorineural Hearing Loss

“…When the central auditory system input is reduced, other sensory inputs would be enhanced correspondingly ( Lomber et al, 2010 ). Previous fMRI studies demonstrated that there may exist transmodal neural change in the visual and sensory system in patients with sensorineural hearing loss (SNHL), which reflects the compensation of brain function ( Lomber et al, 2010 ; Chen et al, 2020 ). In this study, CBF increase in visual-related areas, suggesting that there may be similar visual compensation in patients with SSNHL.…”

Functional Magnetic Resonance Imaging Reveals Early Connectivity Changes in the Auditory and Vestibular Cortices in Idiopathic Sudden Sensorineural Hearing Loss With Vertigo: A Pilot Study

“…However, some recent studies reported no significant difference in the ReHo value between the ISSNHL patients and the healthy controls in any brain region. The various neuroimaging methods employed and the participants’ heterogeneity may have contributed to the inconsistent results ( Cai et al, 2020 ; Chen et al, 2020 ).…”