Revascularisation using recombinant tPA is the reference treatment of stroke. However, the efficacy of fibrinolysis is about 50%. Several factors, including the size of thrombus, have been associated with revascularisation efficacy.

The aim of this prospective study is to evaluate ex vivo the effect of tPA in patients with stroke with thromboelastography and to correlate results with the clinical outcome of patients. Results may predict revascularisation in patients with stroke.

Inclusion Criteria:

• Patient (> 18 years) with a neurological deficit compatible with a neurovascular pathology eligible for fibrinolysis rtPA and having a proximal occlusion of the middle cerebral artery (segment M1 / M2) or basilar trunk objectified brain imaging (MRI angiography or angio CT).

Exclusion Criteria:

• Any patient with major comorbidity, a pathology of hemostasis or anticoagulant treatment (vitamin K antagonist (VKA), direct oral anticoagulant).

All patients meeting the eligibility criteria will be invited to participate in the study . Patients will be recruited to emergencies CHU Caen and Saint Joseph Hospital. The goal is to recruit patients with neurological defect consistent with a neurovascular pathology eligible for thrombolysis with tPA.

With the admission of patients, blood samples are routinely made . For this study, the investigators will add one citrated 5 mL tube. An information letter and consent form will be given to the patient.