Cerebral Microhemorrhages: Significance, Associations, Diagnosis, and Treatment.

OPINION STATEMENT: Cerebrovascular pathologies expose patients to both ischemic and hemorrhagic risks. Given the progressive aging of populations, more and more patients will experience both types of events during their lifetime. The generalization of brain magnetic resonance imaging as a first-line imaging modality for evaluating patients with cerebrovascular diseases has led to the need to manage new types of imaging information about the cerebral tissue, such as the presence, location, and number of cerebral microhemorrhages (CMs). Originally, CMs were thought to be merely spatially localized distortions of the image, mostly secondary to foci of iron deposition within the brain parenchyma. During the past 20 years, however, innumerable research studies have demonstrated that these small foci of signal loss, presumably related to a circumscribed rupture of small vessels, may be used to better estimate the balance between hemorrhagic and ischemic risks. We are now entering the era of personalized medicine, in which treatment decisions are adjusted for each patient according to various genetic, biological, or imaging data. Therefore, integrating CMs into patient management at the individual level will be crucial in the future. This review aims to deliver some clues to interpret the impact of CMs on our clinical decisions.