Inclusion Criteria1. Group of stroke patients:
- Patients between 40 and 70 years old, male or female
- With supratentorial ischemia in subacute phase (> H24)
- Patients with a recent ischemic stroke with an intracranial hemodynamic unstable and kept lying with head down of about 30
- Patient given free and informed consent to participate in research or a family representative
- Patient insured under the French social security system
2. Control Group:
1- Group of patients with Hypertension.
- Patients between 40 and 70 years old, matched for age and sex to stroke patients.
- With a hypertension diagnosed since 10 years old.
- Hypertension defined as three recommendations (OMS 1999, ANAES 1997 JNC VI): blood pressure 140 and / or 90 mmHg found at several consultations.
2- Group with healthy people.
- Healthy person between 30 and 70 years old, women and men. Healthy character will be defined on the basis of a physical examination (measurement of heart rate and blood pressure ) and an examination to determine the absence of endocrine pathology ... ) and the absence of drug outlet continuous.
- Person insured under the French social security system.
- Person who given free and informed his consent to participate in research or a family representative.
- Person who are not participating in another clinical study.
Exclusion Criteria- Patients aged under 40 years and 71 years and older for patients in groups of stroke patients and patients with hypertension
- Person under 30 years and 71 years and older for healthy people
- Person who refuses or family the participation in the study
- Person with heart antecedent or spinal disease
- Contraindications to the realization of a MRI (pacemaker, claustrophobia, metallic body may be mobilized).
- Person not insured under the French social security system,
- Pregnant women
- Persons under guardianship or curatorship
- Persons deprived of liberty by a judicial or administrative decision
- Persons who are participating in another clinical study