Aberrant auditory metabolite levels and topological properties are associated with cognitive decline in presbycusis patients.

Presbycusis has been reported as related to cognitive decline, but its underlying neurophysiological mechanism is still unclear. This study aimed to investigate the relationship between metabolite levels, cognitive function, and node characteristics in presbycusis based on graph theory methods. Eighty-four elderly individuals with presbycusis and 63 age-matched normal hearing controls underwent magnetic resonance spectroscopy, functional magnetic resonance imaging scans, audiological assessment, and cognitive assessment. Compared with the normal hearing group, presbycusis patients exhibited reduced gamma-aminobutyric acid and glutamate levels in the auditory region, increased nodal characteristics in the temporal lobe and precuneus, as well as decreased nodal characteristics in the superior occipital gyrus and medial orbital. The right gamma-aminobutyric acid levels were negatively correlated with the degree centrality in the right precuneus and the executive function. Degree centrality in the right precuneus exhibited significant correlations with information processing speed and executive function, while degree centrality in the left medial orbital demonstrated a negative association with speech recognition ability. The degree centrality and node efficiency in the superior occipital gyrus exhibited a negative association with hearing loss and speech recognition ability, respectively. These observed changes indicate alterations in metabolite levels and reorganization patterns at the brain network level after auditory deprivation.

Abnormal white and gray matter functional connectivity is associated with cognitive dysfunction in presbycusis.

Presbycusis is characterized by high-frequency hearing loss and is closely associated with cognitive decline. Previous studies have observed functional reorganization of gray matter in presbycusis, but the information transmission between gray matter and white matter remains ill-defined. Using resting-state functional magnetic resonance imaging, we investigated differences in functional connectivity (GM-GM, WM-WM, and GM-WM) between 60 patients with presbycusis and 57 healthy controls. Subsequently, we examined the correlation between these connectivity differences with high-frequency hearing loss as well as cognitive impairment. Our results revealed significant alterations in functional connectivity involving the body of the corpus callosum, posterior limbs of the internal capsule, retrolenticular region of the internal capsule, and the gray matter regions in presbycusis. Notably, disrupted functional connectivity was observed between the body of the corpus callosum and ventral anterior cingulate cortex in presbycusis, which was associated with impaired attention. Additionally, enhanced functional connectivity was found in presbycusis between the internal capsule and the ventral auditory processing stream, which was related to impaired cognition in multiple domains. These two patterns of altered functional connectivity between gray matter and white matter may involve both bottom-up and top-down regulation of cognitive function. These findings provide novel insights into understanding cognitive compensation and resource redistribution mechanisms in presbycusis.

Degree centrality and functional connections in presbycusis with and without cognitive impairments.

Presbycusis is a major public issue that affecting elderly adults. However, the neural substrates between normal cognition and cognitive deficits in these patients need to be illustrated. 47 patients with presbycusis and 33 well-matched healthy controls were recruited in present study. Each subject underwent pure-tone audiometry (PTA), MRI scanning and cognition evaluations, then we found 22 patients with cognitive deficits and 25 patients with common cognition. We analyzed the Degree centrality (DC) characteristics among three groups, and try to recognize key nodes which contribute significantly. Subsequent functional connectivity analysis was applied using the key nodes as seeds. Compared with controls, presbycusis without cognitive impairments showed deceased DC in superior temporal gyrus (STG), inferior frontal gyrus (IFG) and supramarginal gyrus (SMG). Additionally, presbycusis with cognitive impairments showed enhanced DC in fusiform gurus (FFG), cerebellum and para-hippocampal gyrus (PHG), while weakened DC in SMG, middle frontal gyrus (IFG) and inferior Parietal lobule (IPL). Compared with normal cognition, increased DC value of cerebellum and STG, as well as decreased DC value of IPL in presbycusis with cognitive impairments were observed. We noticed that SMG may play an important role. Then the left and right SMG were used as seeds in functional connections analysis. With the seed set at left SMG, presbycusis without cognitive impairments showed decreases connections with cerebellum, temporal pole (TP), superior temporal gyrus (STG) and median cingulate cortex (MCC). Presbycusis with cognitive impairments showed weakened connectivity with cerebellum, IFG, IPL and superior frontal gyrus (SFG). The right SMG showed decrease connections with cerebellum, middle temporal gyrus (MTG), STG and increase connection with middle frontal gyrus (MFG) in presbycusis without cognitive impairments. While the right SMG showed enhanced connections with left TP, caudate, anterior cingulate cortex (ACC), angular, SFG and weakened connectivity with right SFG presbycusis with cognitive impairments. In comparison with normal cognition and impaired cognition, MFG, IFG, PHG, rolandic operculum and cerebellum were involved. These findings enriched our understanding of the neural mechanisms underlying cognitive impairments associated with presbycusis and may serve as a potential imaging biomarker for investigating and predicting cognitive difficulties.

Quality Improvement in Otolaryngology-Head and Neck Surgery: Age-Related Hearing Loss Measures.

BACKGROUND AND SIGNIFICANCE: There is a high and growing prevalence of age-related hearing loss (ARHL), defined as presbycusis or bilateral, symmetric sensorineural hearing loss in older adults. Due to the increasing prevalence of ARHL, the potential delays in its diagnosis and treatment, and the significant disability associated with ARHL, the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) convened a Measures Development Group (MDG) to develop quality measures (QMs) of clinical practice that could be incorporated into the AAO-HNSF's data registry Reg-ent. Although the AAO-HNSF has been engaged in robust clinical practice guideline development since 2006, the development of quality and performance measures is more recent. METHODS: We report the process, experience, and outcomes in developing a de novo QM set for ARHL in the absence of a preexisting clinical practice guideline on this topic. Steps include the MDG review of evidentiary literature on ARHL, followed by stakeholder discussions to develop measure specifications. Key considerations included discussion on the relative importance, usability, and feasibility of each measure within the Reg-ent or similar databases. RESULTS: The MDG created 4 QMs for the diagnosis and treatment of AHRL. These measures represent the AAO-HNSF's quality initiatives to develop evidence-based QMs and improve patient care and outcomes, and they are intended to assist providers in enhancing quality of care. CONCLUSION: Development of the ARHL measures is intended for clinicians to evaluate the patient perception, structure, process, and outcomes of care. This process represents a new stage in the AAO-HNSF's measure development efforts to facilitate future efforts in evidence-based QM.

Directed functional connectivity of the hippocampus in patients with presbycusis.

Presbycusis, associated with a diminished quality of life characterized by bilateral sensorineural hearing loss at high frequencies, has become an increasingly critical public health problem. This study aimed to identify directed functional connectivity (FC) of the hippocampus in patients with presbycusis and to explore the causes if the directed functional connections of the hippocampus were disrupted. Presbycusis patients (n = 32) and age-, sex-, and education-matched healthy controls (n = 40) were included in this study. The seed regions of bilateral hippocampus were selected to identify directed FC in patients with presbycusis using Granger causality analysis (GCA) approach. Correlation analyses were conducted to detect the associations of disrupted directed FC of hippocampus with clinical measures of presbycusis. Compared to healthy controls, decreased directed FC between inferior parietal lobule, insula, right supplementary motor area, middle temporal gyrus and hippocampus were detected in presbycusis patients. Furthermore, a negative correlation between TMB score and the decline of directed FC from left inferior parietal lobule to left hippocampus (r = -0.423, p = 0.025) and from right inferior parietal lobule to right hippocampus (r = -0.516, p = 0.005) were also observed. The decreased directed functional connections of the hippocampus were detected in patients with presbycusis, which was associated with specific cognitive performance. This study mainly emphasizes the crucial role of hippocampus in presbycusis and will enhance our understanding of the neuropathological mechanisms of presbycusis.

Age-related hearing loss accelerates cerebrospinal fluid tau levels and brain atrophy: a longitudinal study.

Age-related hearing loss (ARHL) has been considered as a promising modifiable risk factor for cognitive impairment and dementia. Nonetheless, it is still unclear whether age-related hearing loss associates with neurodegenerative biomarkers of Alzheimer's disease (AD). Participants with ARHL were selected from the established Alzheimer's Disease Neuroimaging Initiative (ADNI) database. In multivariable models, the cross-sectional and longitudinal associations of ARHL with CSF ß-amyloid (Aß) and tau measurements, brain Aß load, and cortical structural measures were explored. ARHL was associated with higher CSF levels of tau (p < 0.001) or ptau181 (p < 0.05) at baseline as well as faster elevation rates of these two types of biomarkers (p < 0.05). Although the baseline volume/thickness of hippocampus (p < 0.05) and entorhinal cortex (p < 0.0005) were higher in individuals with ARHL, these two regions (p < 0.01 for hippocampus, p < 0.05 for entorhinal cortex) displayed significantly accelerated atrophy in individuals with ARHL. No association of ARHL with CSF or brain Aß levels was found. Subgroup analyses indicated that the above effects of ARHL were more significant in non-demented stage. Age-related hearing loss was associated with elevated cerebrospinal fluid tau levels and atrophy of entorhinal cortex.

[Diffusion tensor imaging of the central auditory system in the elderly].

Objective:To evaluate the changes in the central auditory system of presbycusis by applying auditury brainstem response (ABR) and diffusion tensor imaging (DTI). Method:A total of twenty-five elderly subjects with expressed presbycusis, eight elderly subjects with normal hearing and fifteen healthy volunteers as young controls were enrolled in the study. Each participant was examined using ABR and DTI. ABR measures were obtained from all the subjects. The fractional anisotropy (FA) was measured at two brain regions of the auditory pathway-the inferior colliculus (IC) and Heschl's gyrus. Result:Higher FA values were recorded at the left side of the Heschl's gyrus in all three groups (P<0.05). There were no significant differences between the left and right side of the ABR results and FA values of inferior colliculus in the three groups (P>0.05). Aging increased ABR peak latencies, yet did not change the Ⅰ-Ⅴ interpeak latency interval. Comparing with the elderly subjects with normal hearing group, the wave Ⅴ latencies of the presbycusis group were prolonged (P<0.05). Comparing with the healthy control group, the FA values of the IC were reduced in both of the elderly subjects with normal hearing group and the presbycusis group (P<0.05). No statistically differences were observed between the presbycusis group and the elderly subjects with normal hearing group in the FA values of the IC (P>0.05). Significant differences between all groups were found in the FA values of the Heschl's gyrus, with higher values in the elderly subjects with normal hearing group than in the presbycusis group and even higher values in the healthy control group than in the elderly subjects with normal hearing group (P<0.05). Conclusion:The results indicated that the age-related microstructural changes exist in the central part of the auditory system, which are more obvious in the patients with presbycusis.

Functional changes in the human auditory cortex in ageing.

Hearing loss, presbycusis, is one of the most common sensory declines in the ageing population. Presbycusis is characterised by a deterioration in the processing of temporal sound features as well as a decline in speech perception, thus indicating a possible central component. With the aim to explore the central component of presbycusis, we studied the function of the auditory cortex by functional MRI in two groups of elderly subjects (>65 years) and compared the results with young subjects (

The relationship between presbycusis and mastoid pneumatization.

Presbycusis is defined as the natural hearing loss accompanying aging, caused by degenerative changes in the inner ear. The etiology of presbycusis is uncertain. However, it would appear that a complex genetic cause is most likely. The determinants of mastoid size continue to be controversial. One of the pneumatization theories is the hereditary theory. In this study, the possible relationship between presbycusis and the extent of mastoid pneumatization was investigated. This study was carried out on 21 patients with presbycusis and 21 normal subjects of similar ages. The pneumatized volume was measured by computerized tomography. The temporal bone was scanned at 2 mm thickness intervals. Exposure (kV 130, mA105). The scan plane was parallel to the orbitomeatal line and the CT images covered the entire mastoid region. The average mastoid pneumatization in presbycusis group was 6.08 +/- 2.52 cm(3) in the right ear and 6.19 +/- 2.93 cm(3) in the left ear. However, in the control group it was 4.69 +/- 3.17 cm(3) in the right ear (p=0.12) and 5.10 +/- 3.49 cm(3) in the left ear (p=0.28). No significant difference was found between the presbycusis patients and normal subjects in terms of the volume of mastoid pneumatization.