Stopping Cognitive Decline and Dementia by Fighting Covert Cerebral Small Vessel Disease

Inclusion Criteria: For the extensive cSVD patient group 1. For the extensive cSVD patient group included in the LEOPOLD trial: * Patients aged 60 to 88 years, * Patients included in the LEOPOLD trial and having performed their brain MRI on SIEMENS PRISMA machine * Being affiliated or beneficiary of the French national health insurance ("sécurité sociale"), * Free, informed and written consent signed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research study). 2. For the extensive cSVD patient group not included in the LEOPOLD trial: * Patients aged 60 to 88 years, * Patients with a cognitive complaint MMSE ≥ 20 performed in the 6 months before inclusion, associated or not with impaired cognitive tests and/or diaognosis of incipient dementia without pronounced cognitive deterioration, * Patients with a socio-educational level ≥ 3, * Patients with a moderate to high grade of hypersignals on an MRI OR on an CT scan performed prior inclusion (grades C and D of the modified Scheltens scale or grade 2/3 Fazekas), * Arterial hypertension defined by a Systolic Blood Pressure (SBP) and / or Diastolic Blood Pressure (DBP) ≥ 140/90 mmHg (according to the definition of the national health authority \[HAS\]), treated or not, confirmed within the previous 12 months or at the latest on the day of inclusion. * Being affiliated or beneficiary of the French national health insurance ("sécurité sociale"), * Free, informed and written consent signed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research study) For the minimal cSVD patient group: * Patients aged 60 to 88 years, * Patients with a cognitive complaint (MMSE ≥ 20 performed at the SHIVA inclusion visit or in the 6 monts prior the visit) associated or not with impaired cognitive tests and/or diagnosis of incipient dementia without pronounced cognitive deterioration, * Patients with little or no white matter hypertensities on brain MRI (grades 0 or 1 on the Fazekas scale); without lacunes or microbleeds, * Arterial hypertension defined by a Systolic Blood Pressure (SBP) and / or Diastolic Blood Pressure (DBP) ≥ 140/90 mmHg (according to the definition of the national health authority \[HAS\]), treated or not, confirmed within the previous 12 months or at the latest on the day of inclusion. Blood pressure values for this inclusion criterion can be objectified by several self-measurements performed by the patient at home for 3 days in a sitting or lying position (3 measurements on sitting or lying position and 3 measurements in standing position). * Being affiliated or beneficiary of the French national health insurance ("sécurité sociale"), * Free, informed and written consent signed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research study Exclusion Criteria: For Extensive cSVD patient group : 1. For the extensive cSVD patient group also included in the LEOPOLD trial: * patients with severe myopia greater than -6 dioptres * partients with known allergy to Tropicamide (Mydriaticum®) * patients with an extensive cataract * patients with ptosis 2. For the extensive cSVD patient group not included in the LEOPOLD trial: * Orthostatic hypotension defined by a decrease of 20 mmHg in SBP and / or 10 mmHg in DBP in a standing position at 3 minutes sought in the previous 3 months or on the day of inclusion, * Very severe renal impairment (creatinine clearance less than 15 ml / min) on a blood test dating back less than one year, * Secondary hypertension: renovascular hypertension, primary hyperaldosteronism, pheochromocytoma... * Contraindication to MRI (presence of a ferromagnetic foreign body, in particular certain intracranial clips, certain heart valves, an intraocular foreign body, metal prosthesis, subject carrying a pacemaker, subject carrying prosthetic heart valves incompatible with MRI. ventricular shunt, claustrophobia), * Associated severe diseases, with a life expectancy of less than 3 months, * Physical problems likely to interfere with the feasibility of the tests (sight, hearing, etc.), * Existence of dementia of which the etiology is distinct from Alzheimer's disease, vascular or mixed dementia * Persons under tutorship or curatorship, * Patients with loss of autonomy living in EHPAD (nursing home) * patients with severe myopia greater than -6 dioptres * participants with known allergy to Tropicamide (Mydriaticum®) * patients with an extensive cataract * patients with ptosis For the minimal cSVD patient group: * Orthostatic hypotension defined by a decrease of 20 mmHg in SBP and / or 10 mmHg in DBP in a standing position at 3 minutes sought in the previous 3 months or on the day of inclusion, * Very severe renal impairment (creatinine clearance less than 15 ml / min) on a blood test dating back less than one year, * Secondary hypertension: renovascular hypertension, primary hyperaldosteronism, pheochromocytoma... * Contraindication to MRI (presence of a ferromagnetic foreign body, in particular certain intracranial clips, certain heart valves, an intraocular foreign body, metal prosthesis, subject carrying a pacemaker, subject carrying prosthetic heart valves incompatible with MRI. ventricular shunt, claustrophobia), * Associated severe diseases, with a life expectancy of less than 3 months, * Physical problems likely to interfere with the feasibility of the tests (sight, hearing, etc.), * Existence of dementia of which the etiology is distinct from Alzheimer's disease, vascular or mixed dementia * Persons under tutorship or curatorship, * Patients with loss of autonomy living in EHPAD (nursing home) * Patients with severe myopia greater than -6 dioptries * Patients with known allergy to Tropicamide (Mydriaticum®) * Patients with an extensive cataract * Patients with ptosis