A transient ischemic attack (TIA) should be considered an emergency prevention opportunity in order to avoid recurrence as cerebral infarction (CI) serious (fatal or disabling). Indeed, about 20% of patients who have IC had in previous days or weeks, a TIA, which can be defined as a brief episode of cerebral dysfunction (or eye) do not result in permanent brain damage and thus no sequelae. Moreover, about 20% of ischemic events observed in practice are AIT. Despite the progress achieved in the treatment in the acute phase of an IC, prevention remains the most effective way to fight against this disease. This prevention can be put in place before the occurrence of a first IC, or after a first IC, especially when minor as a TIA.

However, the diagnosis of TIA remains particularly difficult and it is necessary now to identify new tools for the diagnosis of transient ischemic attack. Our study focused on the identification of one or more molecules (called biological markers or biomarkers) present in the bloodstream of patients, which will serve to facilitate the differential diagnosis of patients with TIA.

Inclusion Criteria:

• TIA lasting 18h
• NIHSS < 0
• MRI diffusion hypersignal less than 5 ml
• follow up during 3 month
• written informed consent prior to any study procedures

Exclusion Criteria:

• Pregnant or breastfeeding women
• major comorbidity (cancer, chronic infection)
• recent trauma (less than 30 days) (cranial or extracranial)
• Surgical or endovascular recent surgery(within 30 days).
• Any old brain injury
• Any acute pathology likely to induce inflammation, hemostasis disorders ...
• Contraindications to MRI: Patients with a pacemaker, an implanted material activated by an electrical, magnetic or mechanical carriers hemostatic clips intracerebral aneurysms or carotid arteries, bearing orthopedic implants, claustrophobic ...
• Patient under guardianship