Bo Liu

Conventional qualitative eye movement examinations may miss subtle abnormalities, complicating early and accurate diagnosis of progressive supranuclear palsy (PSP). Quantitative oculography, represented by video-oculography (VOG), provides an objective digital assessment of eye movements. This review summarizes abnormalities in advanced eye movement tasks in PSP, including prosaccades (ProSs), antisaccades (ASs), memory-guided saccades (MGSs), predictive saccades (PSs), overlap saccades (OSs) and gap saccades (GSs), and considers their underlying pathophysiological mechanisms. Quantitative metrics from these tasks may help distinguish PSP subtypes and PSP from other neurodegenerative diseases, such as Parkinson’s disease (PD), multiple system atrophy (MSA), corticobasal degeneration (CBD) and Alzheimer’s disease (AD). Advanced eye movement measures are therefore promising candidate biomarkers for PSP diagnosis and longitudinal disease monitoring.

Objective: Delayed endolymphatic hydrops (DEH) and Ménière’s disease (MD) are both hydropic ear disease. In MD patients, the endotypes of MD are classified based on pathological types of the endolymphatic sac (ES), which can be distinguished by a radiological indicator: the angular trajectory of the vestibular aqueduct (ATVA). Studies have exhibited that MD patients of different pathological types of ES manifest different clinical characteristics. Here, we aimed to investigate the prevalence of each ATVA category in DEH and MD, and to further explore the clinical significance of ATVA in ipsilateral DEH patients. Methods: Twenty-seven ipsilateral DEH patients, 114 unilateral MD patients and 45 control participants were enrolled in the present study. The ATVA was determined using temporal bone CT imaging. Clinical features, including gender, age and the caloric test results, were collected. The prevalence of ATVA categories were compared between patients with ipsilateral DEH and unilateral MD. The association between ATVA and clinical features was also examined. Results: (1) Compared to MD-affected ears, ATVA ≤ 120° was more frequent (χ ² = 9.231, p = 0.002), whereas ATVA ≥ 140° was less frequent in DEH-affected ears (χ ² = 6.865, p = 0.009). (2) Compared to control ears, the distribution of ATVA categories in affected ears of ipsilateral DEH patients was not significantly different (χ ² = 1.190, p = 0.510). (3) The prevalence of ATVA ≥ 140°, 120° < ATVA < 140° and ATVA ≤ 120° in affected ears of ipsilateral DEH patients was comparable to that in non-affected ears (χ ² = 1.083, p = 0.568). Conclusion: Compared to unilateral MD patients, degenerative ES may be the dominant pathological type in ipsilateral DEH patients due to the high occurrence of ATVA ≤ 120°.

Dementia is primarily characterized by cognitive dysfunction, which is one of the major causes of disability. As hearing loss has been identified as the largest modifiable risk factor for dementia, understanding the intrinsic relationship between the two is crucial for preventing and mitigating the progression of dementia. A body of research has demonstrated a close association between hearing loss and morphological changes in the brain; however, the underlying molecular mechanisms require further elucidation. This review synthesizes current evidence on tau protein, amyloid beta protein, glutamate, gamma-aminobutyric acid, reactive oxygen species, and brain-derived neurotrophic factor to clarify potential molecular pathways linking hearing loss with cognitive dysfunction and to identify candidate targets for future mechanistic and translational studies.

Background: The relationship between seasonal variation and Ménière disease (MD) has not been fully elucidated. This meta-analysis aimed to investigate the association between seasonal patterns and the occurrence of MD. Methods: We systematically searched relevant observational studies in PubMed, Embase, Web of Science, the Cochrane Library, and major Chinese databases from inception to July 2025. The subjects included in the study were patients with MD. Seasonal occurrence of MD was the primary outcome. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) and the Joanna Briggs Institute (JBI) critical appraisal scale. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using Stata 18.0, and heterogeneity was assessed using the I ² statistic. Results: A total of five observational studies involving 1,001,636 participants were included in the meta-analysis. With summer as the reference, ORs for spring, winter and autumn were 1.03 (95% CI 1.02–1.04), 0.92 (95% CI 0.91–0.93) and 1.04 (95% CI 0.85–1.26), respectively. Subgroup and sensitivity analysis confirmed the robustness of the findings, showing that the overall estimate was not fully driven by one single study. Conclusion: Our meta-analysis suggests that the occurrence of MD may exhibit seasonal variation across published studies, with seasonal fluctuations characterized by slightly higher occurrence in spring and declining occurrence in winter. The finding may inform patient education and disease management strategies and provide a potential role of environmental factors in the pathophysiology of MD. However, given the limited number of included studies and their geographic concentration in European and Asian populations, further high-quality studies conducted across diverse geographic regions are needed to provide more solid evidence. Systematic review registration: PROSPERO , (CRD420261348182).

We sincerely thank the Editor for the opportunity to respond to this correspondence and are grateful to the authors for their thoughtful and constructive comments on our article

Objectives: To verify the abnormal brain electrical activity of idiopathic tinnitus through auditory event‐related potentials and elucidate the impact of mild hearing loss. Design: Auditory event‐related potentials were collected from 74 patients with idiopathic tinnitus as the primary complaint (divided into a normal hearing group of 39 and a mild hearing loss group of 35 based on hearing level) and 37 healthy volunteers. Various auditory event‐related potential indicators were compared among the groups, and the correlation between these indicators and the clinical characteristics of idiopathic tinnitus patients was analyzed. Results: Idiopathic tinnitus patients with normal hearing have increased P1 amplitude, delayed P300 latency, decreased P300 amplitude, and decreased mismatch negativity (MMN) amplitude. Idiopathic tinnitus patients with mild hearing loss have further reduced P300 amplitude and delayed MMN latency. In addition, the P300 latency of idiopathic tinnitus patients is significantly correlated with the duration of tinnitus and Tinnitus Handicap Inventory (THI) score, the P300 amplitude is significantly correlated with the Pittsburgh Sleep Quality Index (PSQI) score, and the MMN latency is significantly correlated with the duration of tinnitus. Conclusion: Patients with idiopathic tinnitus exhibit abnormalities in multiple auditory event‐related potentials, with mild hearing loss exacerbating some of these abnormalities. Idiopathic tinnitus and mild hearing loss may lead to selective attention and preprocessing dysfunction.

Objectives: To investigate the differences in inner ear anatomical variations between patients with acute low-tone sensorineural hearing loss (ALHL) and those with unilateral stage I/II Ménière’s disease (MD) based on magnetic resonance imaging (MRI). Methods: A total of 30 patients with unilateral ALHL, 41 patients with unilateral stage I/II MD, and 59 healthy controls were enrolled retrospectively. 3.0T MRI was used to evaluate the distance between the vertical part of the posterior semicircular canal and the posterior fossa (PPD) and vestibular aqueduct (VA) visibility. Inter-group and intra-group comparisons and correlation analyses were performed to clarify the characteristics of anatomical variations. Results: (1) There were no significant differences in PPD and VA visibility between ALHL patients and healthy controls; the PPD of unaffected ears in MD patients was significantly shorter than that in healthy controls, while no significant difference was observed in the PPD of affected ears between MD patients and healthy controls. (2) The VA visibility of affected ears in ALHL patients was significantly higher than that in MD patients. (3) No significant intra-group differences in PPD and VA visibility between affected and unaffected ears were noted in ALHL or MD patients. (4) A significant negative correlation was found between the PPD of affected ears and pure tone average of affected ears in MD patients, while no correlations were observed between anatomical indices and clinical characteristics in ALHL patients. Conclusions: Although both ALHL and MD are categorized as hydropic ear diseases, radiological evidences demonstrate that MD patients exhibit inner ear anatomical variations, whereas no significant anatomical variations are observed in ALHL patients. This suggests that anatomical variations in the endolymphatic drainage system may be a predisposing factor for the pathogenesis of unilateral MD rather than for unilateral ALHL.

Objective:This review compares acute low-tone sensorineural hearing loss（ALHL） and stage 1 and 2 Ménière's Disease（MD） in terms of their clinical presentation, audio-vestibular profiles, and pathophysiological mechanisms, aiming to elucidate key distinctions and commonalities to guide differential diagnosis and treatment. Methods:The study included 61 patients with unilateral ALHL and 41 patients with unilateral stage 1 and 2 MD. The demographic characteristics and findings from pure-tone audiometry, electrocochleography（ECochG）, spontaneous nystagmus（SN）, caloric test, vestibular evoked myogenic potentials（VEMP）, and the video head impulse（vHIT） were retrospectively analyzed. Results:①ALHL was associated with a significantly younger age of onset（t=-4.467, Pχ²=7.918, P=0.005） compared to the MD group. ②MD patients exhibited significantly higher mean hearing thresholds than ALHL patients（Z=-5.827, PF=13.901, PZ=-6.963, Pχ²=6.894, P=0.009） and a smaller summating potential/action potential ratio on the affected side（Z=-2.975, P=0.003）. ③No statistically significant difference in SN was found between ALHL and MD patients（χ²=1.051, P=0.305）. No significant differences were found between ALHL and MD patients regarding the abnormality rate of reduced caloric response on the affected side（χ²=1.943, P=0.163）. A lower canal paresis value was observed in ALHL patients compared to those with MD（F=5.345, P=0.024）. There was no significant difference in the abnormality rates of cervical VEMP（χ²=0.091, P=0.763） or ocular VEMP（χ²=1.024, P=0.312） between the groups. vHIT results were negative in all patients of both groups. Conclusion:Although both ALHL and stage 1 and 2 MD are hydropic disorders with comparable hearing loss patterns, their divergent clinical and audio-vestibular profiles point to differences in pathophysiology. Clarifying their interrelationship calls for additional long-term studies.

Differentiating Ménière's disease (MD) from vestibular migraine (VM) is clinically significant. We aimed to compare the diagnostic performance of two MRI parameters, endolymphatic hydrops (ELH) and endolymphatic drainage system, in distinguishing MD from VM and to explore their correlations. Fifty-five MD and 34 VM patients underwent 3D-FLAIR sequences after intratympanic gadolinium injection. ELH was evaluated with Nakashima criteria, and endolymphatic drainage system parameters, including the distance between the vertical part of the posterior semicircular canal and the posterior fossa (MRI-PPD) and the vestibular aqueduct (MRI-VA) visibility, were assessed. (1) MD patients had higher cochlear and vestibular ELH grades and vestibular ELH ratio on the affected side compared to VM patients. MD patients showed bilaterally reduced MRI-VA visibility compared to VM patients. (2) Higher cochlear and vestibular ELH grades were associated with reduced MRI-VA visibility, and increased cochlear ELH grade correlated with shorter PPD. MRI-VA invisibility and short PPD, may be interrelated features of inner ear ELH in vivo. Moreover, the bilaterally symmetrical reduction of VA visibility may be a potential biomarker in differentiating MD from VM, with comparable efficiency as that of ELH.

Objective. This study aimed to investigate the association between vestibular impairment and neurovascular compression at cerebellopontine angle (CPA) and internal auditory canal (IAC) in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).Methods. Seventy-one ISSNHL patients underwent audio-vestibular tests and magnetic resonance imaging (MRI) of CPA-IAC. The MRI findings of both ears were graded by Chavda, Gorrie and Kazawa systems. Results. No significant association was found between different neurovascular types and the results of caloric test, vestibular evoked myogenic potentials and video head impulse test (vHIT). Chavda type II was more common in ISSNHL patients with vertigo. Tinnitus, initial and outcome hearing threshold showed no significant differences among different neurovascular types. ISSNHL patients with Gorrie type C had worse hearing prognosis than those with type B. ISSNHL patients with pathological vHIT results in the posterior semicircular canal were more prone to poor hearing recovery. Conclusions. Vestibular testing results and radiological neurovascular compression signs in CPA-IAC region may not be associated in ISSNHL patients. Vestibular impairment is more closely related to hearing outcomes than neurovascular compression.