Association of hearing impairment with brain volume changes in older adults

Abstract

Hearing impairment in older adults is independently associated in longitudinal studies with accelerated cognitive decline and incident dementia, and in cross-sectional studies, with reduced volumes in the auditory cortex. Whether peripheral hearing impairment is associated with accelerated rates of brain atrophy is unclear. We analyzed brain volume measurements from magnetic resonance brain scans of individuals with normal hearing versus hearing impairment (speech-frequency pure tone average > 25 dB) followed in the neuroimaging substudy of the Baltimore Longitudinal Study of Aging for a mean of 6.4 years after the baseline scan (n = 126, age 56–86 years). Brain volume measurements were performed with semi-automated region-of-interest (ROI) algorithms, and brain volume trajectories were analyzed with mixed-effects regression models adjusted for demographic and cardiovascular factors. We found that individuals with hearing impairment (n = 51) compared to those with normal hearing (n = 75) had accelerated volume declines in whole brain and regional volumes in the right temporal lobe (superior, middle, and inferior temporal gyri, parahippocampus, p < .05). These results were robust to adjustment for multiple confounders and were consistent with voxel-based analyses, which also implicated right greater than left temporal regions. These findings demonstrate that peripheral hearing impairment is independently associated with accelerated brain atrophy in whole brain and regional volumes concentrated in the right temporal lobe. Further studies investigating the mechanistic basis of the observed associations are needed.

Hearing Impairment and Incident Dementia: Findings from the English Longitudinal Study of Ageing

“…Finally, lack of interaction and intellectual stimulation has been associated with dementia in prospective studies 38, 39. Social gatherings may be more challenging for individuals with hearing impairment because they use more cognitive resources to process speech, which may increase withdrawal from social activities.…”

Hearing Aid Use in Older Adults With Postlingual Sensorineural Hearing Loss: Protocol for a Prospective Cohort Study (Preprint)

“…Consistent with these sequelae, individuals with SNHL exhibit accelerated brain atrophy compared to normal hearing adults, especially within right temporal lobe structures [20] that are critical for many cognitive functions. These findings are corroborated by reports that SNHL patients exhibit atrophic and plastic alteration within cortical brain areas that underpin normal speech processing [21,22].…”

Mild Cognitive Impairment: Still a Controversial Stage between Normal Cognitive Aging and Dementia

“…Changes in anatomy have been documented, such as brain volume shrinkage, synaptic degeneration and subsequent compensatory mechanisms (with greater neural activity). 11 However, whether hearing loss has a causative role in cognitive decline, or it should be described as a risk factor for the development of dementia, or if both hearing loss and cognitive decline are parts of a common age-related degeneration still remains unclear. 12 Given the important connection between auditory and cognitive aging, health care services should be improved by taking into account both hearing and brain changes over the life span.…”