COVID‐19 is Associated with an Unusual Pattern of Brain Microbleeds in Critically Ill Patients

Abstract

Covid-19, initially described as a respiratory system's infection, is currently more and more recognized as a multiorganic disease, including neurological manifestations. There is growing evidence about a potential neuroinvasive role of SARS-CoV-2. The purpose of this study is to describe new findings, in the form of cerebral microbleeds affecting different brain structures, observed in MRIs of critically ill patients. METHODS: For this purpose, the MR images of 9 patients with a common pattern of abnormal findings (2 women/7 men; 55-79 years of age; mean age: 67.7 years) were depicted. All patients were tested positive for SARS-CoV-2 and presented with delayed recovery of consciousness or important agitation, requiring brain MRI. RESULTS: All patients had suffered from severe (5/9) or moderate (4/9) acute respiratory distress syndrome, requiring prolonged stay in the intensive care unit. Their common MRI finding was the presence of microbleeds in unusual distribution with a specific predilection for the corpus callosum. Other uncommon locations of microbleeds were the internal capsule (5/9), as well as middle cerebellar peduncles (5/9). Subcortical regions were also affected in the majority of patients. CONCLUSIONS: Brain MRI raised evidence that Covid-19 or its related treatment may involve the brain with an unusual pattern of microbleeds, predominantly affecting the corpus callosum. The mechanism of this finding is still unclear but the differential diagnosis should include thrombotic microangiopathy related to direct or indirect-through the cytokine cascade-damage by the SARS-CoV-2 on the endothelium of brain's vessels, as well as mechanisms similar to the hypoxemia brain-blood-barrier injury.

Critical illness-associated cerebral microbleeds for patients with severe COVID-19: etiologic hypotheses

“…We retrospectively compared these 19 patients to 18 other ICU patients with COVID-19, similar ARDS, and neurological manifestations, but with a normal cerebral MRI, to understand the underlying pathophysiological mechanisms. [2] France (multicentric) 9 Hypoxemia/small vessel vasculitis Vattoth [3] Qatar (monocentric) 1 Hypoxemia Chougar [4] Paris (monocentric) 8 ECMO/anticoagulation overdose/microangiopathy Klironomos [5] Stockholm (monocentric) 23 Hypoxemia/microangiopathy/endothelial injury/ECMO Lin [6] New York [2hospitals] 3 Mechanical ventilation Paterson [7] UK (multicentric) 4 Endothelial injury Fitsiori [8] Geneva (monocentric) 9 Endothelial injury related to SARS-CoV-2/microangiopathy/ECMO/ Hypoxemia/disseminated intravascular coagulation/hypercoagulable state Freeman [9] Philadelphia (monocentric)…”

“…Recently, some cerebral complications related to COVID-19 were depicted on brain MRIs. Diffuse microbleeds, located in the white matter (WM) with an atypical distribution affecting, in particular, the corpus callosum, has recently been described in critically ill patients with COVID-19 [1][2][3][4][5][6][7][8][9]. A recent neuropathological study has also described hemorrhagic lesions disseminated throughout cerebral WM in a patient with severe COVID-19 [10].…”

Insights Into Neuroimaging Findings of Patients With Coronavirus Disease 2019 Presenting With Neurological Manifestations

“…De Stefano et al (33) reported the first case of a critically ill patient with COVID-19 with massive multifocal parenchymal microhemorrhage on SWI while no parenchymal lesion was observed on T1-or T2-weighted imaging. A case series described unusual micro-hemorrhage distribution, which was located in the corpus callosum, internal capsule, and middle cerebellar peduncles, in nine ICU patients (34). Macro-hemorrhage was also reported.…”

Neuroradiologic manifestations of COVID-19: what the emergency radiologist needs to know

“…Lastly, the authors note that ECMO alone (in the absence of SARS-CoV-2 infection) is a risk factor for intracranial hemorrhage, further limiting the generalizability of this small case series. Notably, however, in a case series of nine patients with COVID-19 (none of whom were on ECMO), Fitsiori et al described cerebral microbleeds in unusual distributions, including involvement of the internal capsule, corpus callosum, and middle cerebellar peduncles [38].…”