**1. Introduction**

Extracellular vesicle (EV) is a term used to define a heterogeneous group of vesicles isolated from biological fluids or tissues. EVs seem to mediate complex cell-to-cell communication over long distances or nearby through various macromolecules: polypeptides, various species of RNAs, and/or lipids.

The classification of EVs is based on their size and mechanism of biogenesis and includes: exosomes, less than 100 nm small vesicles released from multivesicular bodies after endocytosed materials have been sorted in the endolysosomal compartment [1, 2]; ectosomes, up to 500 nm larger vesicles budding from the plasma membrane [2, 3]; and multivesicular cargos, consisting of numerous vesicles, about 150 nm, enclosed in a plasma membrane-derived shield [4]. Although many medical fields experienced real progress with newly discovered diagnostic tools or treatments for several diseases, smaller steps are taken in the field of cerebrovascular and neurodegenerative diseases. Age-related changes, cardiac diseases, and atherosclerosis are known to contribute to the pathogenic mechanism of cerebrovascular and neurodegenerative diseases affecting the elderly.
