1 Introduction
As the global population ages, health issues among the elderly have become increasingly urgent and significant areas of research. The vestibular system is composed of three semicircular canals oriented in different planes and two otolith organs (the utricle and saccule). It maintains gaze stability through the vestibulo-ocular reflex and body balance through the vestibulo-spinal reflex. Studies have shown that with increasing age, various anatomical components of the vestibular system undergo degenerative changes
[1,
2]. Vestibular dysfunction and cognitive decline, in particular, have garnered considerable attention. Peripheral vestibular dysfunction is quite common among older adults, especially those over 70, with a prevalence rate of approximately 7%
[3]. This condition often manifests as dizziness, gait instability or difficulty standing
[4]. Beyond its association with balance disorders, the vestibular system also plays a critical role in various cognitive domains. Studies have shown that individuals with vestibular dysfunction have a fourfold increase in the risk of cognitive impairment, with 12% experiencing functional limitations due to memory problems or confusion
[5,
6]. Moreover, patients with Alzheimer's disease and mild cognitive impairment are more likely to suffer from vestibular dysfunction compared to cognitively normal individuals
[7,
8].
Several studies indicate a link between vestibular dysfunction and balance disorders as well as falls in the elderly
[9,
10]. Furthermore, neuroanatomical studies of the vestibular system suggest that the information transmitted to the limbic system and neocortex through ascending pathways is crucial for higher-order cognitive processes. The hippocampus, a vital component of the limbic system, is a key brain region involved in mediating cognitive dysfunction due to vestibular disorders
[11,
12]. However, some studies have found that vestibular abnormalities do not necessarily lead to changes in brain structures, such as hippocampal volume
[13,
14].
Despite evidence suggesting that the vestibular system plays a crucial role in various cognitive domains
[5,
15,
16], the mechanisms by which vestibular dysfunction contributes to cognitive decline remain unclear. The effects of vestibular damage on hippocampal morphology are complex, and current animal studies and human research results are not yet fully corroborative. Existing studies mainly focus on small samples of patients with vestibular dysfunction
[17], while large cohort studies typically involve older adults living in community settings or those from urban areas in Western countries
[1,
18]. Given the significant differences in lifestyle, culture, and social factors between elderly populations in rural and urban China, further research on vestibular function and cognitive performace among rural populations is not only essential for better understanding their relationship but also provides a theoretical foundation for developing comprehensive intervention strategies in this group population.
This study aims to address existing knowledge gaps by thoroughly analyzing the current status and interplay between vestibular and cognitive function in older adults. It seeks to provide scientific evidence and clinical insights for improving quality of life and developing effective intervention strategies for the aging population
2 Materials and Methods
2.1 Study design and participants
Participants in this study were recruited from the Taizhou Imaging Study (TIS), an ongoing community-based neuroimaging cohort nested within the Taizhou Longitudinal Study (TZL) aimed at monitoring risk factors and progression of dementia and cerebrovascular disease in rural Chinese populations. The TIS was approved by the Ethics Committee of the School of Life Sciences, Fudan University, and Fudan University Taizhou Institute of Health Sciences (institutional review board approval number: 496 and B017, respectively). The study design of TIS has been previously described
[19]. Briefly, from 2013 to 2018, TIS recruited individuals aged 55–65 years without a history of physician-diagnosed stroke, dementia, cancer, or other severe diseases. Participants underwent baseline assessments including epidemiological surveys, physical and clinical examinations (e.g., multimodal brain MRI), and neuropsychological evaluations. In this study, we conducted a cross-sectional analysis using data from 2024, involving 479 participants.
2.2 Measurement
2.2.1 Balance questionnaire and testing
In this study, we designed a balance questionnaire aimed at quickly identifying individuals with subjective vestibular dysfunction. The questionnaire was drafted with reference to the structures of similar large cohort studies and was customized to align with the specific objectives of this research. Given the screening nature of the study, we specifically opted for a simplified questionnaire format rather than using standardized dizziness questionnaires such as the dizziness handicap inventory (DHI).
Before undergoing balance testing, each participant completed the balance questionnaire. This questionnaire assesses the history of vertigo ("In the past year, have you experienced vertigo or unsteady walking?") and falls ("In the past year, have you fallen due to vertigo or unsteady walking?"). Additionally, it includes subjective descriptions of the participant's vertigo symptoms ("If you have experienced vertigo, please describe the sensation"; "How long did the vertigo last?"; "In the past year, have you reduced your daily activities due to vertigo, dizziness, or falls?").
The balance testing includes the modified Romberg Test of Standing Balance on firm and compliant support surfaces to assess the sensory inputs contributing to balance—the vestibular system, vision, and proprioception
[18]. The participant begins with 30 seconds of standing with their eyes closed on a foam surface. During the test, if they open their eyes, move their arms or feet, fall, or require the operator’s assistance, it is considered a failure of the test. If the participant passes this initial test, the assessment is deemed complete. Otherwise, one retest is performed. In case the result remains abnormal for the retest, the following tests are conducted in sequence: ⅰ) standing with eyes open on a foam-padded surface; ⅱ) standing with eyes closed on a firm surface; ⅲ) standing with eyes open on a firm surface.
This study mainly focuses on the first test condition, which is specifically designed to assess vestibular function: participants are required to maintain balance on a foam-padded surface (to obscure proprioceptive input) with their eyes closed (to eliminate visual input). If participants fail to pass this test condition, they are categorized as having vestibular dysfunction.
2.2.2 Cognitive function testing
The neuropsychological tests employed in this study have been validated within the Chinese population, and standardized data have been published
[20]. These tests include: ⅰ) Mini-Mental State Examination (MMSE); ii) Beijing version of the Montreal Cognitive Assessment (MoCA). All assessments were independently conducted by neurologists, neuropsychologists, and trained technicians with over 3 years of experience. Diagnosis of dementia and mild cognitive impairment (MCI) was based on cognitive measurements, clinical manifestations, and specific neuroimaging features, evaluated by a committee of expert neurologists and neuropsychologists according to the
Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV)
[21] and Petersen RC's criteria
[22], respectively, tailored to each participant's cognitive measurements, clinical manifestations, and specific neuroimaging features
[19,
20].
The MMSE scale has a maximum score of 30, with scores of 27–30 indicating normal cognitive function. Similarly, the MoCA scale has a maximum score of 30, with scores of 26 or above indicating normal cognitive function; individuals with ≤ 12 years of education received an adjusted score to account for educational background.
2.3 Statistical analysis
Descriptive statistics were used to summarize the demographic and clinical characteristics of the participants. To compare differences between groups, we employed t-tests for normally distributed continuous variables and Mann-Whitney U tests for non-normally distributed continuous variables. Chi-square tests were used to assess differences in categorical variables. We performed multivariable unconditional logistic regression to explore the association between vestibular dysfunction and cognitive impairment, adjusting for potential confounders including age, sex, education level, BMI, and comorbidities. Pearson correlation coefficients were also calculated to evaluate the relationship between continuous variables and cognitive function scores. All statistical analyses were conducted using R statistical software version 4.3.2, with p-values less than 0.05 considered statistically significant.
3 Results
3.1 Characteristics of the study population
Table 1 summarizes the demographic and cognitive performance characteristics of the study population (n = 479) categorized by vestibular function status. Among the participants, 51 individuals (10.6%) were identified as having vestibular dysfunction. The average age of the participants was 67.73 years (SD = 3.9). Notably, the average age of the vestibular dysfunction group (67.61 years, SD = 3.8) was slightly younger than that of the normal function group (68.76 years, SD = 4.0) (p = 0.044). The overall mean years of education was 4.87 years (IQR: 1.0, 8.0). The average education level in the vestibular dysfunction group (3.55 years) was significantly lower compared to the normal function group (5.03 years) (p = 0.009). Among the whole group, 36 (7.5%) were diagnosed with dementia, and 128 (26.7%) with mild cognitive impairment (MCI). In the vestibular dysfunction group, the prevalence of MCI was 33.3%, and the prevalence of dementia was 13.7%.
The mean MMSE score in the normal vestibular function group was 21.07 (IQR: 18, 26), significantly higher than the mean score in the vestibular dysfunction group, which was 18.67 (IQR: 14, 25) (p = 0.013). Similarly, the mean MoCA score in the normal vestibular function group was 14.65 (IQR: 11, 19), significantly higher than the dysfunction group’s mean score of 12.78 (IQR: 7, 17) (p = 0.040).
3.2 Results on vestibular function status among the elderly in rural China
As shown in Table 2, the Balance Questionnaire indicated that 19.0% of older adults reported experiencing symptoms of vertigo or unsteady gait in the past year, and 5.0% reported having fallen. The proportion of women experiencing vertigo or unsteady gait was 24.0%, higher than the 12.7% observed in men, a difference that was statistically significant (p = 0.003). However, there were no significant differences between men and women in the likelihood of frequently reducing daily activities due to vertigo or unsteady gait or in the incidence of balance-related falls.
We further analyzed the symptom distribution among individuals reporting subjective vestibular dysfunction, as illustrated in Figure 1. The majority of older adults noted that their primary symptom was dizziness, which typically resolved within a short duration.
3.3 Association between vestibular function and cognitive function
As shown in Table 3, Vestibular function (normal) is significantly positive correlated with cognitive function scores (MoCA: r = 0.16, p < 0.05; MMSE: r = 0.19, p < 0.05), indicating that normal vestibular function is associated with higher cognitive function scores. Additionally, gender (male) shows a significant negative correlation with cognitive scores (MoCA: r = −0.41, p < 0.001; MMSE: r = −0.33, p < 0.001), while years of education exhibit a significant positive correlation (MoCA: r = 0.58, p < 0.001; MMSE: r = 0.5, p < 0.001). Hypertension (yes) and body fat percentage are also significantly negatively correlated with cognitive scores (MoCA: r = −0.26, p < 0.01; MMSE: r = −0.23, p < 0.01 and MoCA: r = −0.27, p < 0.001; MMSE: r = −0.24, p < 0.001, respectively). Conversely, alcohol consumption (yes) (MoCA: r = 0.30, p < 0.001; MMSE: r = 0.21, p < 0.001) and physical exercise(yes) (MoCA: r = 0.19, p < 0.01; MMSE: r = 0.14, p < 0.05) are significantly positively correlated with cognitive scores. Other variables, such as age, BMI, hearing loss (PTA), diabetes, and hyperlipidemia, do not show significant correlations with cognitive function scores.
These findings suggest that vestibular function, gender, educational level, hypertension, body fat percentage, alcohol consumption, and physical exercise may influence cognitive function in the elderly to varying degrees.
3.4 Multifactorial analysis of cognitive impairment in the elderly
We bulit a multivariable unconditional logistic regression model by using cognitive function as the dependent variable, categorized as a binary based on the presence or absence of dementia. Exercise habits are included as an independent variable in binary form, indicating whether the individual engages in regular weekly exercise.The results of the analysis, as shown in Figure 2, the risk of developing dementia decreases with higher levels of education (OR = 0.88, 95% CI: 0.77−0.99). Additionally, a higher PTA value indicates poorer hearing, which corresponds to an increased risk of developing dementia. (OR = 1.03, 95% CI: 1−1.07). Therefore, better hearing is considered a protective factor for cognitive function. In contrast, other factors such as vestibular function (OR = 0.98, 95% CI: 0.54−1.61), age (OR = 0.99, 95% CI: 0.91−1.09), BMI (OR = 0.95, 95% CI: 0.83−1.1), gender (OR = 1.03, 95% CI: 1−1.07), and smoking (OR = 0.4, 95% CI: 0.12−1.14) did not show significant association with the risk of developing dementia.
4 Discussion
This study revealed a significant correlation between vestibular function and overall cognitive performance. However, when cognitive function was categorized as either dementia or non-dementia, this relationship did not translate into a significant predictor of dementia onset. Further research is needed to comprehensively elucidate the role of vestibular function in the progression of cognitive decline.
Dementia is the leading cause of disability among individuals aged 65 and older worldwide, including in China. MCI represents a prodromal stage between healthy cognitive aging and dementia, affecting 10% to 15% of the population over the age of 65
[23]. Furthermore, individuals with MCI have an annual progression rate to dementia of 5% to 10%. A meta-analysis and systematic review, which included 233 studies, revealed that the prevalence of MCI among the global population aged 50 and older is 19.7%
[24]. Another cross-sectional study, which included 46,011 participants from 12 provinces in China, found that the prevalence of MCI among the elderly population aged 60 and older in China is 15.5%
[25]. This study investigated 479 individuals aged 60 and above in Taizhou, Jiangsu Province, revealing a prevalence of 26.7% for MCI and 7.5% for dementia among the rural elderly population. These rates are significantly higher than those reported in previous studies. The study employed a more comprehensive and rigorous diagnostic approach and testing methodology. Additionally, factors such as limited healthcare resources and lower educational levels in rural areas may contribute to the higher prevalence of cognitive impairment observed in our research.
The global aging population represents a significant demographic shift. Research indicates that nearly all sensory components of the vestibular system deteriorate with age, severely impacting vestibular function. Existing studies report varying prevalence rates of vestibular dysfunction: a cross-sectional survey in South Korea found a one-year prevalence of vertigo at 16.7%
[26], a study in Taiwan reported a prevalence of 37.7%
[27], and a cross-sectional study in the United States determined a one-year prevalence of vestibular vertigo among adults to be 8.4%
[5]. In our study, 19.0% of elderly participants self-reported vestibular symptoms such as dizziness or unsteady walking in the past year, primarily characterized by brief episodes of dizziness. The consistency of our findings with these international studies underscores the pervasive nature of vestibular issues among the elderly across different populations.
The majority of epidemiological data on vestibular dysfunction, as mentioned above, is based on questionnaire surveys. The advantage of our study is the use of a modified Romberg test to assess vestibular function, aiming to identify balance disorders consistent with vestibular impairment
[28,
29]. In our study, 10.6% of elderly participants were considered to have vestibular dysfunction based on the Romberg test, which is significantly lower than the self-reported incidence of balance disorders (19.0%).
Clinical studies have found that individuals with vertigo and vestibular disorders frequently experience symptoms of memory impairment
[11]. For instance, a cross-sectional study found that vestibular and balance deficits are more prevalent among individuals with greater cognitive decline, such as those with MCI and Alzheimer's disease
[30]. This association is further supported by public health survey data from the United States in 2008
[5]. In our study, participants were grouped based on their Romberg test results. We found that the cognitive function of the vestibular dysfunction group was significantly lower than that of the normal vestibular function group. Additionally, correlation analysis revealed a significant positive relationship between vestibular function and cognitive performance, indicating that better vestibular function is associated with higher cognitive scores. However, in the multivariable unconditional logistic regression analysis with dementia as the dependent variable, vestibular function was not identified as a significant factor influencing dementia prevalence. We believe there are two main reasons for this. Firstly, vestibular compensation is a notable process through which the central nervous system adapts to alterations in vestibular input. According to human studies, many individuals experience significant recovery of cognitive functions related to spatial orientation and balance following vestibular compensation
[31]. According to Kahneman's model of attention capacity, the increased need for attention resources to maintain balance due to vestibular dysfunction, such as gaze instability and postural unsteadiness, may reduce the cognitive resources available for other tasks. The MMSE and MoCA scales can reflect the overall level of cognitive function, but they may not fully capture the specific performance across different cognitive domains, therefore, future research should incorporate a variety of comprehensive assessment methods, such as tests of executive function, attention, and memory, to provide a more thorough evaluation of cognitive characteristics in individuals with vestibular dysfunction. Second, the association and mechanisms between vestibular function and cognition remain inconclusive. Current research suggests four potential pathways through which vestibular function might influence cognition: the thalamocortical pathway, the theta generation pathway, the cerebellocortical pathway, and the head direction pathway. The prevailing hypothesis posits that vestibular information must be processed by the hippocampus to integrate with visual and other sensory data related to spatial memory
[32]. However, some studies have shown that vestibular function does not affect changes in hippocampal volume
[14]. Therefore, while vestibular function may have some impact on general cognitive abilities, there is no definitive evidence regarding its effects on specific types of cognitive disorders or stages of progression.
This study is the first large-scale cohort study in China exploring the relationship between vestibular function and cognitive function in the elderly. However, several limitations remain. First, the sample size in this study is relatively small compared to other national surveys, which may limit the generalizability of the findings. Second, while MMSE and MoCA are widely used to assess cognitive function, they primarily focus on general cognitive abilities and may not adequately assess cognitive domains closely related to vestibular function, such as spatial navigation and executive function. Future research should consider incorporating more domain-specific tests to provide a more comprehensive evaluation of these cognitive areas. Furthermore, although the modified Romberg test is useful for assessing vestibular function, it does not capture all aspects of vestibular function, particularly dynamic balance and the vestibulo-ocular reflex (VOR). Given the screening nature of this study, the Romberg test was chosen over other commonly used vestibular function assessment methods. However, future studies could benefit from incorporating additional assessment methods, such as the video head impulse test, to gain a more thorough understanding of vestibular function and its relationship with cognitive performance.
To further elucidate the impact of changes in vestibular function on cognitive function in the elderly, long-term follow-up studies and more refined testing methods will be essential components of future research.
5 Conclusion
Our study reveals a high prevalence of both vestibular and cognitive impairment among the elderly in rural China. Although a significant correlation exists, vestibular dysfunction was not an independent risk factor for dementia, suggesting it modulates cognitive performance rather than directly driving dementia’s onset. Our findings underscore the need for integrated screening in rural healthcare, combining balance assessments with cognitive tools.
The Author(s) 2025. This article is available under open access at journal.hep.com.cn.
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