The purpose of this study is to evaluate whether Thromboelastography (TEG) parameters on admission might be predictive for early neurological deterioration in acute ischemic stroke patients, specifically for the DWI lesion evolution within the first week after stroke onset.

Early neurological deterioration (END ) is a major concern in stroke care, consistently associated with adverse clinical outcomes.END is a heterogeneous complex of pathophysiological and clinical entities. Despite some straight forward causes, DWI lesion growth is reportedly a primary underlying mechanism. Early recognition of END risk would allow for timely identification and proper intervention, improving stroke health care.

Thromboelastography (TEG) measures the coagulation process from initial clotting cascade to clot strength, providing an integrated picture of two separate but simultaneously occuring components of coagulation, thrombosis and lysis. It has been reported to be associated with short and long-term outcome in patients with trauma, coronary artery diseases , pulmonary embolism and, most recently, stroke prevention.The purposes of this study is to evaluate how effective TEG is on predicting END, by producing a range of TEG values correlated with clinical and radiological assessment.

Inclusion Criteria:

• acute ischemic stroke within 24 hours after symptom onset
• first ever stroke
• give informed consent

Exclusion Criteria:

• receiving thrombolysis
• cardiogenic embolism
• contradiction to serial MRI studies
• taking hemostatic agents (warfarin, oral anticoagulants and etc. )

The study population includes consecutively admitted patients with acute ischemic stroke in Dongguan people's Hospital. Patients would take TEG study within 6 hours after admission, as well as other routine lab tests. Serial MRI studies would be taken on admission and followed up on 7th day afterward, except when patients experience END, in which case followup MRI should be preformed immediately.