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Objective: To compare the clinical features of sudden hearing loss (SHL) in patients with and without endolymphatic hydrops (EH), and to investigate the association between SHL with EH and Ménière's disease (MD). Methods: The clinical data of 63 SHL patients with first symptoms were evaluated retrospectively. Patients were separated into two groups based on the results of gadolinium‐enhanced magnetic resonance imaging: EH and non‐EH groups. Independent sample t‐test and U‐test were used to compare groups for continuous variables, and the chi‐squared test, corrected chi‐squared test and Bonferroni correction test were used to compare groups for binary and ordinal variables. The binary logistic regression model was utilised for univariate and multivariate analysis of follow‐up patient prognosis. Results: The EH and non‐EH groups contained 32 and 31 patients, respectively. The EH group had a higher prevalence of low‐tone descending hearing loss. Fifty‐one patients were followed for more than 2 years. In the EH group, 11 and 15 patients were diagnosed with sudden sensorineural hearing loss (SSNHL) and MD, respectively, while in the non‐EH group, 24 patients were diagnosed with SSNHL and only one with MD. EH, low‐tone descending hearing loss and vertigo were risk factors for the diagnosis of MD in a subgroup univariate regression analysis of patients experiencing SHL. EH was found to be a risk factor for the progression of SHL into MD in a multifactor regression analysis. Conclusions: Patients with SHL who have EH are more likely to present with low‐tone descending hearing loss. EH is a risk factor for the subsequent development of MD. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the differences between audio-vestibular function testing and inner ear gadolinium magnetic resonance imaging (MRI) in distinguishing definite Ménière disease (DMD) and probable Ménière disease (PMD), and to provide a reference for early clinical diagnosis and intervention., Methods: A total of 116 patients diagnosed with DMD (n = 80) and PMD (n = 36) were enrolled. The differences in the results of pure tone audiometry, caloric test, and tympanic injection of gadolinium for contrast-enhanced MRI between the two groups were compared and analyzed. Parameters that could differentiate between the two conditions were identified, and the sensitivity and specificity and the area under the curve (AUC) of individual and combined indices in the differential diagnosis of DMD and PMD were evaluated., Results: The hearing threshold and hearing asymmetry rate of the DMD group were significantly higher than those of the PMD group (p < 0.001), 98.8% and 30.6%, respectively. The abnormal rates of canal paresis (CP) and severity of endolymphatic hydrops in the DMD group were higher than those in the PMD group (p < 0.05). When combined with high-frequency hearing thresholds, hearing asymmetry, hearing curve type, endolymphatic hydrops, and abnormal CP, the diagnostic accuracy of DMD was improved compared to using high-frequency alone (p < 0.05)., Conclusion: This study showed that PMD and DMD may represent two different stages in the development of MD disease. The comprehensive assessment of audio-vestibular function testing and inner ear MRI proves beneficial for early diagnosis, potentially contributing to the preservation of inner ear function., Competing Interests: Conflict of interest statement: The authors have no relevant financial or nonfinancial interests to disclose., (Copyright © 2024, Otology & Neurotology, Inc.)

Systemic inflammation with alterations in inflammatory markers is involved in aging and Alzheimer's disease. However, few studies have investigated the longitudinal trajectories of systemic inflammatory markers during aging and Alzheimer's disease, and specific markers contributing to Alzheimer's disease remain undetermined. In this study, a longitudinal cohort (cohort 1: n = 290; controls, 136; preclinical Alzheimer's disease, 154) and a cross-sectional cohort (cohort 2: n = 351; controls, 62; Alzheimer's disease, 63; vascular dementia, 58; Parkinson's disease dementia, 56; behavioural variant frontotemporal dementia, 57; dementia with Lewy bodies, 55) were included. Plasma levels of inflammatory markers were measured every 2 years during a 10-year follow-up in the longitudinal cohort and once in the cross-sectional cohort. The study demonstrated that the inflammatory markers significantly altered during both aging and the development of Alzheimer's disease. However, only complement C3, interleukin-1β, and interleukin-6 exhibited significant changes in participants with preclinical Alzheimer's disease, and their longitudinal changes were significantly associated with the development of Alzheimer's disease compared to controls over the 10-year follow-up. In the cross-sectional cohort, complement C3 demonstrates specificity to Alzheimer's disease, while interleukin-1β and interleukin-6 were also altered in other dementias. The study provides a new perspective on the involvement of inflammatory markers in the aging process and the development of Alzheimer's disease, implying that regulating inflammation may have a pivotal role in promoting successful aging and in the prevention and treatment of Alzheimer's disease., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Synaptic dysfunction with reduced synaptic protein levels is a core feature of Alzheimer's disease (AD). Synaptic proteins play a central role in memory processing, learning, and AD pathogenesis. Evidence suggests that synaptic proteins in plasma neuronal-derived extracellular vesicles (EVs) are reduced in patients with AD. However, it remains unclear whether levels of synaptic proteins in EVs are associated with hippocampal atrophy of AD and whether upregulating the expression of these synaptic proteins has a beneficial effect on AD., Methods: In this study, we included 57 patients with AD and 56 healthy controls. We evaluated their brain atrophy through magnetic resonance imaging using the medial temporal lobe atrophy score. We measured the levels of four synaptic proteins, including synaptosome-associated protein 25 (SNAP25), growth-associated protein 43 (GAP43), neurogranin, and synaptotagmin 1 in both plasma neuronal-derived EVs and cerebrospinal fluid (CSF). We further examined the association of synaptic protein levels with brain atrophy. We also evaluated the levels of these synaptic proteins in the brains of 5×FAD mice. Then, we loaded rabies virus glycoprotein-engineered EVs with messenger RNAs (mRNAs) encoding GAP43 and SNAP25 and administered these EVs to 5×FAD mice. After treatment, synaptic proteins, dendritic density, and cognitive function were evaluated., Results: The results showed that GAP43, SNAP25, neurogranin, and synaptotagmin 1 were decreased in neuronal-derived EVs but increased in CSF in patients with AD, and the changes corresponded to the severity of brain atrophy. GAP43 and SNAP25 were decreased in the brains of 5×FAD mice. The engineered EVs efficiently and stably delivered these synaptic proteins to the brain, where synaptic protein levels were markedly upregulated. Upregulation of synaptic protein expression could ameliorate cognitive impairment in AD by promoting dendritic density. This marks the first successful delivery of synaptic protein mRNAs via EVs in AD mice, yielding remarkable therapeutic effects., Conclusions: Synaptic proteins are closely related to AD processes. Delivery of synaptic protein mRNAs via EVs stands as a promising effective precision treatment strategy for AD, which significantly advances the current understanding of therapeutic approaches for the disease., (© 2024. The Author(s).)