Cerebral Microbleeds and Anti-thrombotic Treatment

Cerebral microbleeds (CMBs), as hemorrhagic neuroimaging markers of cerebral small-vessel disease, are radiologically defined as small round or ovoid lesions of homogeneous signal intensity loss on T2^*-gradient echo imaging and are believed to represent chronic hemosiderin deposition following microhemorrhage. Histopathological analysis of the vessels associated with CMBs have generally identified two main types of vascular pathological changes: hypertensive vasculopathy and cerebral amyloid angiopathy (CAA). CMBs with strictly lobar distribution are specific for CAA with deposition of β-amyloid in small arterial walls, while CMBs in the basal ganglia, white matter, and brainstem are related to hypertensive small arteries. Previous study showed that CMBs might increase the risk of bleeding. Especially, CMBs increase the risk of hemorrhagic complications in patients on antiplatelet, anticoagulation or thrombolytic therapy. However, whether the bleeding risk overweighs the clinical benefit of antithrombotic treatment remains unclear and warrants further investigations. Furthermore, controlling other risk factors, such as hypertension, alcoholism and renal function, is also an important part of clinical practice when considering the balance between the risks of bleeding and thrombus.