Objective:This study aims to investigate the expression levels of α-synuclein(α-synuclein)and apolipoprotein A-1(ApoA1)in elderly patients with cerebral small vessel disease(CSVD)and their association with cognitive function.Methods:A total of 176 elderly patients diagnosed with CSVD and admitted to Huludao Central Hospital between September 2022 and February 2024 were retrospectively selected as research subjects.Based on their cognitive function at the time of admission, patients were categorized into a disorder group comprising 71 cases and a normal group consisting of 105 cases.General information was collected from the patients, and the serum expression levels of α-synuclein and ApoA1 were measured.Pearson correlation analysis was employed to assess the relationship between the expression levels of α-synuclein and ApoA1 and the Montreal Cognitive Assessment(MoCA)scores.Furthermore, multi-factor logistic regression analysis was conducted to identify influencing factors, and receiver operating characteristic(ROC)curves were generated to evaluate the diagnostic value of serum levels.Results:Patients in the disorder group were older than those in the normal group.Additionally, the MoCA score and serum α-synuclein levels were significantly higher in the disorder group, while ApoA1 levels were lower(all P<0.05).Pearson correlation analysis indicated that the MoCA score was negatively correlated with α-synuclein expression and positively correlated with ApoA1 expression(all P<0.05).Multivariate logistic regression analysis revealed that age, smoking history, and α-synuclein levels are risk factors for cognitive dysfunction in patients with CSVD, whereas ApoA1 is identified as a protective factor for cognitive function in this population.Furthermore, ROC curve analysis demonstrated that serum α-synuclein and ApoA1 levels possess diagnostic value for cognitive dysfunction in patients.The area under the curve(AUC)for the combined predictions was 0.836, with sensitivity and specificity rates of 76.14% and 78.14%, respectively. Conclusions:Elderly patients with CSVD and cognitive dysfunction exhibit abnormally high levels of α-synuclein and abnormally low levels of ApoA1.Both factors are influential in the context of cognitive dysfunction among elderly patients with CSVD and contribute to improved diagnostic efficiency.