Subclinical Vascular Brain Injury

Signs of subclinical vascular brain injury, mostly due to cerebral small vessel disease, are the commonest incidental findings on brain imaging. The cardinal manifestations of cerebral small vessel disease are infarcts, microbleeds, and white matter hyperintensities of presumed vascular origin. Subclinical infarcts and white matter hyperintensities have been associated with increased future risk of stroke and dementia, while silent microbleeds have been associated with increased future risk of both hemorrhagic and ischemic stroke. Workup should include a careful history of symptoms to verify whether the lesions are truly silent. There are no large trials to guide management of subclinical vascular brain injury. However, vascular risk should be assessed and prudently managed. Whether to start an antiplatelet agent in patients with subclinical infarcts is controversial because there is no supportive evidence from clinical trials. The risk of future intracranial hemorrhage in patients with microbleeds taking anticoagulants has probably been overstated in the past. Newer meta-analyses suggest that most patients with microbleeds have a higher risk of future ischemic stroke than hemorrhagic stroke, and thus should probably be given antithrombotics if they are indicated to reduce the risk of thromboembolism.