The primary objective of this observational study is to investigate alterations in PrPc levels in peripheral blood during acute cerebral infarction, as well as the correlation between these changes and both disease severity and prognosis. Additionally, it aims to explore the association between peripheral blood PrPc and T-cell-mediated inflammatory responses in acute cerebral infarction. Key research questions addressed include: how PrPc concentrations in peripheral blood change during acute cerebral infarction, and whether such variations correlate with clinical severity and patient outcomes. No interventions were administered in this study, and all patients received standard diagnostic and therapeutic care without disruption. Fasting venous blood samples were collected on the morning following hospital admission, and follow-up assessments using the modified Rankin Scale (mRS) were conducted at 90 days post-onset.