Aneurysmal subarachnoid hemorrhage is a common and serious disease associated to a high rate of mortality and morbidity. Severe definitive neurological impairment can concern up to 30% of patients in relation with elevated intracranial pressure, hemorrhage recurrence and symptomatic cerebral arterial vasospasm. This latter complication is defined as a reversible reduction of cerebral artery's diameter occurring between the 4th and the 14th day after bleeding. Physiopathology is not well understood, but could involve endothelium, trough endothelial progenitor cells (EPC). Circulating EPC are bone marrow-derived cells with capacity of vasculogenesis and angiogenesis. EPC have been recognized playing a beneficial role in cardiovascular disease and ischemic stroke. EPC have never been studied in aneurysmal subarachnoid hemorrhage.

The primary objective of this study is to compare the number of circulating endothelial progenitor cells between patients with a good neurological outcome (defined as a glasgow outcome scale = 1 or 2) and patients with a poor neurological outcome (glasgow outcome scale = 3, 4 or 5).

Briefly, the number of circulating EPC will be measured at admission, and at day 3, 6, 10, 14, 21 in each consecutive patient suffering aneurysmal subarachnoid hemorrhage and hospitalized in Teaching Hospital of Besançon (France). The neurological outcome will be measured one year after subarachnoid hemorrhage.

Inclusion Criteria:

• recent(< 24 h) aneurysmal subarachnoid hemorrhage
• written informed consent obtained from the patient or from close relatives

Exclusion Criteria:

• refusal to participate
• Non-aneurysmal subarachnoid hemorrhage
• aneurysmal subarachnoid hemorrhage with estimated date of bleeding > 24 h
• Chronic heart failure
• Chronic medication able to modify the plasmatic level of BNP
• Pregnancy

Consecutive patients suffering from acute aneurysmal subarachnoid haemorrhage. .