Critical illness-associated cerebral microbleeds (CIACM) after urosepsis: An under-recognized cause of persistent encephalopathy in the ICU

Critical illness–associated cerebral microbleeds (CIACM) are increasingly recognized as a form of structural brain injury in critically ill patients, particularly in the setting of sepsis, severe hypoxemia, and multiorgan failure. On susceptibility-weighted MRI, CIACM typically shows a characteristic distribution involving the corpus callosum, juxtacortical white matter, brainstem, and cerebellum, with relative sparing of the deep gray nuclei. However, deep gray nuclei involvement may be observed in more severe cases, supporting the concept of diffuse microvascular injury rather than a focal neurologic disorder. Although the exact mechanism remains not completely elucidated, endothelial dysfunction, blood–brain barrier disruption, and hypoxia-related microangiopathy are playing major roles. Clinically, CIACM carries important significances, including prolonged encephalopathy, uncertainty in neurologic prognostication, and challenges related to anticoagulation management. Despite growing recognition, the condition likely remains underdiagnosed because MRI is not routinely performed in critically ill patients with persistent altered mental status. We describe a patient with septic shock secondary to obstructive uropathy who developed persistent encephalopathy and was later found to have CIACM on MRI.