Study of the Function of Cerebral Venous System in Acute Ischemic Stroke Patients Receiving Reperfusion Therapy

Stroke therapy had entered a new era since endovascular therapy was introduced in addition to intravenous thrombolysis. The benefit of endovascular therapy for patients with a proven proximal intracranial arterial occlusion has recently been revealed in several large randomized controlled trials. However, a substantial number of patients treated with reperfusion therapy did not reach functional independence in long-term follow-up, despite relatively high recanalization rates. Therefore, simple and more reliable markers that identify patients most likely to benefit from reperfusion therapy are needed. Accumulated studies showed that arterial status such as arterial collaterals had been considered as a critical predictor of outcome or determinant criteria for therapeutic selection. However, other evidences denied that arterial collaterals serve as a predictors for outcome after recanalization. Moreover, non-reflow phenomenon, over-reperfusion and futile recanalization may lead to large infarct, brain swelling, hemorrhagic complication and neurological deterioration. The traditional pathophysiological understanding on ischemic stroke can hardly explain these occurrences. Recently, the importance of cerebral venous drainage, the major blood reservoir and drainage system in brain, has been described for stroke evolution and clinical sequelae. In this study, the aim is to investigate the roles of cerebral venous dynamic status on neurological outcome after reperfusion therapy and the potential mechanisms behind poor veins and adverse outcome. In this study, the investigators will prospectively recruit the AIS patients over 18 years old who undergo baseline CTP/MRP and receive reperfusion therapy within 24 hour after onset. Each of their perfusion imaging will be reconstructed to evaluate the status of cerebral vein system. The investigators hypothesized that the venous dynamic status may have effect on the ischemic-reperfusion progress, and may thus has the potential to impact the stroke outcome. This study may add new implications for stroke outcome prediction and future therapeutic decision-making.