Permanent Cerebral Oxymetry Monitoring for Early Diagnosis and Treatment of Delayed Vasospasm After Subarachnoid Hemorrhage

Inclusion Criteria: * Men and women * Age ≥ 18 years * HSA of aneurysmal etiology less than 4 days before inclusion diagnosed by clinical presentation and emergency imaging * HSA "severe" defined according to the WFNS ≥ III * Intubated-ventilated patient or any other reason preventing a contributing neurological examination * Affiliate or beneficiary of a social security scheme * Free, informed and written consent signed by the representative Exclusion Criteria: * Age \<18 years * Significant vasospasm as soon as the detection was detected on the initial imaging * Possible Neurological Surveillance * Patient in limitation of active therapeutics or with high probability of soon limitation of active therapeutics * Intra-parenchymal frontal haematoma limiting the quality of measurement, diagnosed on imaging (Less than 25mm deep from the skin) * Patient in limitation of active therapeutics or with high probability of soon limitation of active therapeutics * Adhesive allergy to measuring patches * Patient under guardianship or safeguard of justice * Refusal of legal representative