Disrupted glymphatic system and brain network reorganization in age-related hearing loss

Age-Related Hearing Loss (ARHL), a prevalent sensory deficit linked to cognitive decline, lacks well-defined neuropathological mechanisms. This study investigated glymphatic dysfunction and brain network reorganization in ARHL using multimodal MRI. We enrolled 178 participants (69 healthy controls, 79 mild ARHL, 30 moderate ARHL), assessing glymphatic activity via diffusion tensor image analysis along the perivascular space (DTI-ALPS) index, perivascular space (PVS) volume, choroid plexus volume (CPV), and functional network topology. Results revealed progressive glymphatic impairment (DTI-ALPS decline, PVS volume enlargement, and increased CPV) alongside cognitive decline, reflected by reduced Montreal Cognitive Assessment (MoCA) and Complex Figure Test-delayed recall (CFTd) scores. Brain networks exhibited abnormal global and nodal metrics. Mediation analysis demonstrated that glymphatic dysfunction partially explains the association between disrupted global network efficiency and cognitive deficits. A combined biomarker model (DTI-ALPS + PVS + CPV) demonstrated superior diagnostic accuracy compared to individual markers. These findings indicate that glymphatic dysfunction and brain network reorganization are associated with ARHL severity, with the integrated biomarker panel showing potential for clinical stratification.