Sensorineural hearing loss and cognitive impairments: Contributions of thalamus using multiparametric MRI

Abstract

Background The thalamus is an integrative hub conveying sensory information between cortical areas and related to cognition. However, alterations of the thalamus following partial hearing deprivation remains unknown. Purpose To investigate the modifications of the thalamus and its seven subdivisions in terms of structure, function, and perfusion in subjects with sensorineural hearing loss (SNHL), as well as their associations with SNHL‐induced cognitive impairments. Study Type Cross‐sectional study. Subjects Thirty‐seven bilateral long‐term SNHL patients and 38 well‐matched controls. Field Strength 3 T/BOLD, T1‐weighted imaging, arterial spin labeling (ASL). Assessment Quantitative measurements in the thalamus and subdivisions were obtained, including the relative volume, fractional amplitude of low‐frequency fluctuation (fALFF) within slow 5 (0.01–0.027 Hz), slow 4 (0.027–0.073 Hz), and combined frequency (0.01–0.073 Hz), as well as the whole‐brain functional connectivity. Twenty‐five SNHL patients and 20 controls underwent ASL scanning. Then correlation analysis was computed between all significant changes and cognition tests. Statistical Tests Continuous and categorical variables were compared by independent‐sample t‐test and chi‐square test, respectively. Quantitative MRI measurement comparisons were corrected for multiple comparison, and functional connectivity (FC) analysis used two‐sample t‐test with false‐discovery rate correction. Area under the curve (AUC) in receiver operating characteristic curve analysis was applied to evaluate the power of alterations in differentiating SNHL and controls. Results No significant difference in the relative volume and perfusion of seven thalamus subdivisions were observed, but a decrease in fALFF in SNHL. SNHL showed reduced thalamic connectivity with the cerebellum lobule VIII, ventral anterior cingulate cortex, insula, superior temporal gyrus, media temporal gyrus, medial frontal gyrus, Heschl's gyrus, and temporal pole. And some FC abnormalities exhibited positive correlations with cognitive tests and high discriminative power (0.8 < AUC < 1) in two groups. Data Conclusion SNHL led to decreased thalamic activity and widespread weakened connectivity with other brain areas. Level of Evidence: 2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:787–797.

Altered Functional Network in Infants With Profound Bilateral Congenital Sensorineural Hearing Loss: A Graph Theory Analysis

“…It also mediates important functions including memory, emotion, and attention (Arend et al, 2015;Geier et al, 2020). Imaging evidence has also shown decreased thalamic functional connectivity with both auditory and non-auditory regions in long-term SNHL patients (Xu et al, 2019). Our finding was consistent with Xu et al's (2019) result.…”

Changes of the Brain Causal Connectivity Networks in Patients With Long-Term Bilateral Hearing Loss

“…Resting-state fMRI studies reported increased functional connectivity and abnormal neural activities in the default mode network (DMN) of individuals with hearing loss compared with normally hearing subjects (Husain et al, 2014;Xu et al, 2017). In addition, previous studies also reported decreased resting-state functional connectivity from the insula to the DMN (Xu et al, 2019a,d), as well as reduced thalamic connectivity with the DMN (Xu et al, 2019c). These investigations indicate that hearing loss leads to neural activity changes in the DMN, which is responsible for cognitive processing (Wheeler et al, 2006;Leech et al, 2011).…”

Silence, Solitude, and Serotonin: Neural Mechanisms Linking Hearing Loss and Social Isolation

“…Other imaging studies in human subjects have shown that sensorineural hearing loss is associated with a widespread decrease in connectivity in multiple functional brain networks involved in decoding or assessing the meaning of the acoustic environment. These networks include auditory cortical regions and the insula, amygdala, and different cerebellar subregions that combine multimodal sensory information with information on internal state [ 171 , 172 , 173 , 174 ]. For some networks, the lack of connectivity further correlates with measures of speech comprehension, as well as general measures of cognitive performance or affective state.…”