Microbleed patterns in critical illness and COVID-19

Abstract

Background Cerebral microbleeds are increasingly reported in critical ill patients with respiratory failure in need of mechanical ventilation and/or extracorporeal membrane oxygenation (ECMO). Typically, these critical illness-associated microbleeds involve the juxtacortical white matter and corpus callosum. Recently, this pattern was reported in patients with respiratory failure, suffering from COVID-19. Materials and methods In this retrospective single-center study, we listed patients from March 11, 2020 to September 2, 2020, with laboratory-confirmed COVID-19, critical illness and cerebral microbleeds. Literature research was conducted through a methodical search on Pubmed databases on critical illness-associated microbleeds and cerebral microbleeds described in patients with COVID-19. Results and discussion On 279 COVID-19 admissions, two cases of cerebral microbleeds were detected in critical ill patients with respiratory failure due to COVID-19. Based on review of existing literature critical illness-associated microbleeds tend to predominate in subcortical white matter and corpus callosum. Cerebral microbleeds in patients with COVID-19 tend to follow similar patterns as reported in critical illness-associated microbleeds. Hence, one patient with typical critical illness-associated microbleeds and COVID-19 is reported. However, a new pattern of widespread cortico-juxtacortical microbleeds, predominantly in the anterior vascular territory with relative sparing of deep gray matter, corpus callosum and infratentorial structures is documented in a second case. The possible etiologies of these microbleeds include hypoxia, hemorrhagic diathesis, brain endothelial erythrophagocytosis and/or cytokinopathies. An association with COVID-19 remains to be determined. Conclusion Further systematic investigation of microbleed patterns in patients with neurological impairment and COVID-19 is necessary.

Neurologic Complications of Patients With COVID-19 Requiring Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

“…Of the 54 studies, 11 studies reported on ischemic strokes and 41 studies reported on ICHs. There were two case reports on mononeuritis multiplex (10,11), one case report on brachial plexopathy (12), three case reports on critical illness myopathy or neuropathy (12)(13)(14), five studies on cerebral microbleeds (12,(15)(16)(17)(18), and one case report of posterior reversible encephalopathy syndrome (18). Lastly, there were two studies that reported venous causes for neurovascular complications (19,20) and two studies that used electroencephalogram to investigate the electrophysiologic changes of patients with COVID-19 on ECMO (21,22).…”

“…Characterized as small hypointense foci on gradient echo sequences or susceptibility weighted imaging, cerebral microbleeds associated with ECMO are typically found in the juxtacortical white matter and splenium of the corpus callosum. Three case reports and one case-control study noted cerebral microbleeds on MRI ( 12 , 15 – 17 ). There are several proposed mechanisms for ECMO-associated microbleeds, including hypoxia-induced microbleeds, gas emboli from ECMO, or infection-mediated microangiopathy.…”

Comparison between the persistence of post COVID-19 symptoms on critical patients requiring invasive mechanical ventilation and non-critical patients

“…This should be assumed according to the recent findings from the UK Biobank study, where COVID-19 patients had a significant loss of grey matter in the left parahypocampal gyrus, the left lateral orbitofrontal cortex and the left insula [ 33 ]. In addition to the gray matter decrease, COVID-19 critically ill patients also tend to have more incidence of microbleed at follow up [ 34 ], mainly found in the juxtacortical white matter, corpus callosum and internal capsule [ 35 , 36 ]. The implications of these structural and vascular alterations must be considered at the long term follow up of these patients, therefore cognitive and neurological evaluation should be carried out periodically.…”

Cerebral Microbleeds on Susceptibility Weighted Imaging Following Severe COVID-19 Infection

“…The pathophysiology of cerebral microbleeds is unknown but postulated to be multifactorial secondary to hypoxia, a proinflammatory state, hypercoagulability, disruption of endothelial cells and the blood brain barrier [2,6,7]. The presence of cerebral microbleeds and/or leukoencephalopathy remains associated with critical illness, worse functional outcome, increased hospitalization, increased morbidity and increased mortality in COVID-19 patients [3]. Earlier recognition of SARS-COV2 leukoencephalopathy and/or cerebral microbleeds could possibly modify and improve patient outcomes.…”