Inclusion Criteria:
* Any clinically silent ischemic lesions of the brain parenchyma detected on neuroimaging defined according to established criteria as either:
* DWI positive lesions: Focus of restricted diffusion (high DWI signal and low ADC value) occurring in either white or gray matter, located in the cerebrum, cerebellum, or brain stem AND not satisfying the diagnostic criteria for MS OR
* Cavitatory Lesions: ≥ 3 mm in size that follow CSF on all sequences that are slit or wedge shaped with an irregular margin AND NOT longitudinally aligned with perforating vessels or with a multiple, bilateral symmetrical distribution OR
* T2W hyperintense/T1W hypointense lesions: Focal lesion with high T2W signal and low T1W signal that have prior evidence of restricted diffusion; OR present within cortical gray matter or deep gray matter nuclei OR a lesion that is new, compared with an MRI performed within 3 months OR T2W hyper/T1W hypointense lesions in the white matter, which are discontinuous but associated with the classic confluent periventricular T2 intense change of leukoaraiosis (Fazekas ≥2) AND NOT satisfying the diagnostic criteria for MS or with a significant patient history of severe trauma, radiation, drug toxicity, or carbon monoxide poisoning
* Informed Consent as documented by signature by patient or legally authorized representative
Exclusion Criteria:
* Projected life expectancy of less than 2 years,
* Contraindication to MRI,
* Patients with a history of symptoms compatible with an AIS/TIA attributable to the lesion observed, covert neurological deficits are allowed,
* Patient is already included in another clinical trial that will affect the objectives of this study,
* Patient's lack of accountability, inability to appreciate the nature, meaning and consequences of the study and to formulate his/her own wishes correspondingly,
* Women who are pregnant or breast feeding or intention to become pregnant during the course of the study,
* Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
* Contraindications to any of the routine procedures, e.g. inability to obtain neurovascular ultrasound examination,
* Known or suspected non-compliance, drug or alcohol abuse
