Cerebral Microvascular Injury in Severe COVID-19

Structured AbstractO_ST_ABSImportanceC_ST_ABSCerebral microvascular lesions are common in patients with severe COVID-19. Radiologic-pathologic correlation in one case suggests a combination of microvascular hemorrhagic and ischemic lesions that may reflect an underlying hypoxic mechanism of injury, which requires validation in larger studies. ObjectiveTo determine the incidence, distribution, and clinical and histopathologic correlates of microvascular lesions in patients with severe COVID-19. DesignObservational, retrospective cohort study: March to May 2020. SettingSingle academic medical center. ParticipantsConsecutive patients (n=16) admitted to the intensive care unit with severe COVID-19, undergoing brain MRI for evaluation of coma or focal neurologic deficits. ExposuresNot applicable. Main Outcome and MeasuresHypointense microvascular lesions identified by a prototype ultrafast high-resolution susceptibility-weighted imaging (SWI) MRI sequence, counted by two neuroradiologists and categorized by neuroanatomic location. Clinical and laboratory data (most recent measurements before brain MRI). Brain autopsy and cerebrospinal fluid PCR for SARS-CoV-2 in one patient who died from severe COVID-19. ResultsEleven of 16 patients (69%) had punctate and linear SWI lesions in the subcortical and deep white matter, and eight patients (50%) had >10 SWI lesions. In 4/16 patients (25%), lesions involved the corpus callosum. Brain autopsy in one patient revealed that SWI lesions corresponded to widespread microvascular injury, characterized by perivascular and parenchymal petechial hemorrhages and microscopic ischemic lesions. Conclusions and RelevanceSWI lesions are common in patients with neurological manifestations of severe COVID-19 (coma and focal neurologic deficits). The distribution of lesions is similar to that seen in patients with hypoxic respiratory failure, sepsis, and disseminated intravascular coagulation. Collectively, these radiologic and histopathologic findings suggest that patients with severe COVID-19 are at risk for multifocal microvascular hemorrhagic and ischemic lesions in the subcortical and deep white matter. Key Points SectionO_ST_ABSQuestionC_ST_ABSWhat is the prevalence and pathophysiology of cerebral microvascular injury in patients with severe COVID-19? FindingsIn this retrospective cohort study of 16 patients undergoing MRI for neurologic complications of severe COVID-19, microvascular lesions were observed in 11 patients and showed an anatomic distribution similar to that seen in patients with hypoxic respiratory failure and sepsis. In one patient who died, brain autopsy revealed widespread microvascular injury, including perivascular microhemorrhages and microscopic ischemic lesions. MeaningMicrovascular injury is common in patients with severe COVID-19. Radiologic-pathologic correlation, though limited to a single case, provides insights into possible mechanisms of injury.

BRAIN MR SPECTROSCOPIC FINDINGS IN THREE CONSECUTIVE COVID-19 PATIENTS: PRELIMINARY OBSERVATIONS

Brain magnetic resonance spectroscopic imaging (MRSI) was performed in three consecutive COVID-19 patients, as part of a pilot investigation of the pathophysiological processes underlying the brain involvement by the SARS-CoV-2 infection. These included one with necrotizing leukoencephalopathy, one after recent PEA cardiac arrest without leukoencephalopathy, and one without frank encephalopathy or recent severe hypoxic episode. The MRSI findings were compared to those of two patients with white matter pathology not SARS-CoV2 infection related, and a control patient without clinical encephalopathy. The N-acetylaspartate reduction, choline elevation, and glutamate/glutamine elevation found in the COVID necrotizing leukoencephalopathy patient and, to a lesser degree, the COVID post-cardiac arrest patient, follow a similar pattern as seen with the delayed post-hypoxic leukoencephalopathy patient. Lactate elevation was most pronounced in the patient with COVID necrotizing leukoencephalopathy.