Hearing loss impacts gray and white matter across the lifespan: Systematic review, meta-analysis and meta-regression

Abstract

Hearing loss is a heterogeneous disorder thought to affect brain reorganization across the lifespan. Here, structural alterations of the brain due to hearing loss are assessed by using unique effect size metrics based on Cohen’s d and Hedges’ g . These metrics are used to map coordinates of gray matter (GM) and white matter (WM) alterations from bilateral congenital and acquired hearing loss populations. A systematic review and meta-analysis revealed m = 72 studies with structural alterations measured with magnetic resonance imaging (MRI) (bilateral = 64, unilateral = 8). The bilateral studies categorized hearing loss into congenital and acquired cases ( n = 7,445) and control cases ( n = 2,924), containing 66,545 datapoint metrics. Hearing loss was found to affect GM and underlying WM in nearly every region of the brain. In congenital hearing loss, GM decreased most in the frontal lobe. Similarly, acquired hearing loss had a decrease in frontal lobe GM, albeit the insula was most decreased. In congenital, WM underlying the frontal lobe GM was most decreased. In congenital, the right hemisphere was more negatively impacted than the left hemisphere; however, in acquired, this was the opposite. The WM alterations most frequently underlined GM alterations in congenital hearing loss, while acquired hearing loss studies did not frequently assess the WM metric. Future studies should use the endophenotype of hearing loss as a prognostic template for discerning clinical outcomes.

Structural Alterations in a Rat Model of Short-Term Conductive Hearing Loss Are Associated With Reduced Resting State Functional Connectivity

“…In humans, we have recently assessed the structural foundations of hearing loss across the lifespan (Manno et al, 2021). Our systematic review and meta-analysis revealed n = 72 studies with structural alterations measured by MRI (bilateral = 64, unilateral = 8).…”

“…We have recently assessed the structural foundations of hearing loss across the lifespan in humans using a meta-analysis and meta-regression (Manno et al, 2021). In humans, we found that hearing loss not only affects auditory structures, but is brainwide, multi-focal, and impacts regions and tracts differently depending on auditory input and compensatory mechanisms.…”

Aging Brain and Hearing: A Mini-Review

“…Even when limited to MRI-based studies, the main research targets are wide-ranging, such as the auditory cortex, including the primary auditory cortex, whole brain volume, GM, WM, and non-auditory cortex ( Manno et al, 2021 ). Manno et al (2021) , conducted a comprehensive systematic review, meta-analysis, and meta-regression of the structural alterations of the brain due to hearing loss, and assessed the impact on the brain of pediatric, adult, and aged adult populations, to identify whether the etiology is congenital or acquired.…”

“…Even when limited to MRI-based studies, the main research targets are wide-ranging, such as the auditory cortex, including the primary auditory cortex, whole brain volume, GM, WM, and non-auditory cortex ( Manno et al, 2021 ). Manno et al (2021) , conducted a comprehensive systematic review, meta-analysis, and meta-regression of the structural alterations of the brain due to hearing loss, and assessed the impact on the brain of pediatric, adult, and aged adult populations, to identify whether the etiology is congenital or acquired. Manno et al (2021) , stated that the impact of hearing loss on the brain was multifocal and not limited to the temporal lobe and that hearing loss was found to affect the GM and the underlying WM in nearly every region of the brain and affected all populations.…”

Disrupted Topological Organization in White Matter Networks in Unilateral Sudden Sensorineural Hearing Loss

“…At present, the main treatment for SSNHL is steroid therapy ( Jung et al, 2016 ). Unfortunately, the hearing function of patients with SSNHL shows little improvement even after suitable high-quality therapy, which may negatively affect economic indicators for the society and result in the poor long-term quality of their life ( Manno et al, 2021 ).…”