RÉSUMÉ
@#Objective To observe cerebral microbleeds （CMBs）, cognitive function, and the protein expression level of hyperphosphorylated Tau （P-Tau） in patients with cerebral infarction and obstructive sleep apnea-hypopnea syndrome （OSAHS）, to analyze their differences between the cerebral infarction+OSAHS group and the control group, and to further investigate the degree of cognitive impairment in patients with cerebral infarction and OSAHS and the association between the protein expression level of P-Tau and CMBs. Methods A prospective analysis was performed for 199 patients with cerebral infarction who were admitted to Stroke Center in our hospital from December 2019 to December 2022, among whom there were 94 patients with OSAHS （cerebral infarction+OSAHS group） and 105 patients without OSAHS （control group）, and CMBs and Montreal Cognitive Assessment （MoCA） score were assessed for the two groups. The two groups were compared in terms of changes in the protein expression level of P-Tau before treatment and after 7 and 14 days of treatment. The receiver operating characteristic （ROC） curve was used to describe the predictive efficacy of P-Tau protein level before treatment for the cognitive function of patients with cerebral infarction CMBs and OSAHS, and the Pearson correlation coefficient was used to investigate the correlation of the scores of each dimension of MoCA scale with P-Tau protein level before treatment. With the score of MoCA scale as the basis for assessing the degree of cognitive impairment, 94 patients were divided into mild impairment group, moderate impairment group, and severe impairment group, and P-Tau protein level before treatment was compared between the three groups. Results Compared with the patients in the control group, the patients with cerebral infarction and OSAHS had a significantly lower MoCA score （P<0.05） and a higher occurrence rate of CMBs, especially in those with mild grade. Before treatment, the cerebral infarction+OSAHS group had a significantly higher P-Tau protein level than the control group （P<0.05）, and after 7 and 14 days of treatment, the cerebral infarction+OSAHS group had no significant change in P-Tau protein level （P>0.05）, while the control group had a significant reduction in P-Tau protein level （P<0.05）. P-Tau protein level before treatment showed a sensitivity of 67.31% and a specificity of 90.48% in the diagnosis of cognitive impairment in the patients with cerebral infarction CMBs and OSAHS, and the Pearson correlation analysis showed that the scores of visuospatial/executive, attention and computational ability, language, abstraction, and delayed memory in MoCA scale were negatively correlated with P-Tau protein level before treatment in these patients （P<0.05）. There was a significant difference in P-Tau protein level before treatment between the mild impairment group, the moderate impairment group, and the severe impairment group （P<0.05）. Conclusion P-Tau protein level before treatment is associated with cognitive impairment in patients with cerebral infarction CMBs and OSAHS, which can guide the diagnosis and severity assessment of the disease in clinical practice.