Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a syndrome described at the end of the 20th century. Generally, it has a benign course. It is revealed by acute headaches, in different circumstances such as sexual activity, physical exertion or emotional disturbances. But, in few cases, it might be complicated by seizure, stroke and subarachnoid haemorrhage. The diagnosis is confirmed on radiological examination, which shows diffuse cerebral vasoconstriction of brain vessel. It calls reversible because at three month, vasoconstriction disappears. Most cases occur during post partum or after serotoninergic/adrenergic drug use. The pathophysiology is unknown but a transient disturbance in the control of cerebrovascular tone by sympathic hyperactivity and/or endothelial dysfunction are suspected. The assessment of endothelial dysfunction in brain is possible with transcranial doppler. Chen et al. showed an impairment of vasodilatation post apnea induced called BHI on RCVS subjects compared with healthy control. BHI is a reflect of endothelial function in brain. Currently, investigators do not know if endothelial dysfunction occurred only in brain or if it may occur in systemic vessel. Some case reports talk about systemic complication such as kidney infarct or hepatic arterial vasospasm so a systemic vascular dysfunction may be suspected. In this study, researchers will study systemic endothelial function by measure of the pulse wave velocity during RCVS and after its recovering at 3 months, and compare it at healthy controls.

The investigators lead a case control study to find a systemic endothelial dysfunction by the using of Complior device. Complior is a mechanographer who calculates pulse wave velocity (PWV). Pulse wave velocity is a reflect of arterial stiffness and it's correlate with endothelial dysfunction. For BHI, a Philips echograph is used before and after 30 second of breath holding.

Study protocol is :

For Patient :

• Day 0 : in hospital : anamnesis, medical history, physic examination, EKG, blood sample analysis, BHI, PWV analysis
• Month 1 : in medical visit : medical evolution, physic examination, EKG, blood sample analysis, BHI, PWV analysis
• Month 3 : in medical visit : medical evolution, physic examination, EKG, blood sample analysis, BHI, PWV analysis, cerebral angioCT Scan

For control :

- Day 0 : in hospital : medical history, physic examination, EKG, BHI, PWV analysis

Inclusion Criteria for patients :

• Aged from 18 to 80 years old
• RVCS diagnosis evoked on clinic and radiologic finding
• Last headache was 15 days ago
• Oral consent
• Register in French social security

Inclusion criteria for control :

• Aged from 18 to 80 years old
• Hypothesis of RCVS in clinical presentation and on cerebral imaging
• Last headache less than 3 days old
• Oral consent
• Register in French social security
• Person under guardianship, curatorship or safeguarding of justice

Exclusion Criteria:

Non inclusion criteria for patient :

• Pregnant women
• Tobacco, coffee, alcohol, drugs or vasoactive recreational substances use within 2 hours prior to the examination.
• Person under guardianship, curatorship or safeguarding of justice
• Non sinusal rhythm on EKG
• Impossible of Breath holding for 30 secondes

Exclusion criteria for patient :

- No reversibility at 3 months

Non inclusion criteria for control :

• Pregnant women
• Tobacco, coffee, alcohol, drugs or vasoactive recreational substances use within 2 hours prior to the examination.
• Non sinusal rhythm on EKG
• Impossible of Breath holding for 30 secondes

Patients and Healthy subjects