Brain MRI Findings in Severe COVID-19: A Retrospective Observational Study

BACKGROUND: Brain MRI parenchymal signal abnormalities have been in association with SARS-CoV-2. PURPOSE: Describe the neuroimaging findings (excluding ischemic infarcts) in patients with severe COVID-19 infection. METHODS: This was a retrospective study of patients evaluated from March 23th, 2020 to April 27th, 2020 at 16 hospitals. Inclusion criteria were: (i) positive nasopharyngeal or lower respiratory tract reverse transcriptase-polymerase chain reaction assays; (ii) severe COVID infection defined as requirement for hospitalization and oxygen therapy; (iii) neurologic manifestations; (iv) abnormal brain MRI. Exclusion criteria were patients with missing or non-contributory data regarding brain MRI or a brain MRI showing ischemic infarcts, cerebral venous thrombosis, or chronic lesions unrelated to the current event. Categorical data were compared using Fisher exact test. Quantitative data were compared using Student’s t-test or Wilcoxon test. A p-value lower than 0.05 was considered significant. RESULTS: Thirty men (81%) and 7 women (19%) met inclusion criteria, with a mean age of 61+/- 12 years (range: 8-78). The most common neurologic manifestations were alteration of consciousness (27/37, 73%), pathological wakefulness when the sedation was stopped (15/37, 41%), confusion (12/37, 32%), and agitation (7/37, 19%). The most frequent MRI findings were: signal abnormalities located in the medial temporal lobe in 16/37 (43%, 95% CI 27-59%) patients, non-confluent multifocal white matter hyperintense lesions on FLAIR and diffusion sequences, with variable enhancement, with associated hemorrhagic lesions in 11/37 patients (30%, 95% CI 15-45%), and extensive and isolated white matter microhemorrhages in 9/37 patients (24%, 95% CI 10-38%). A majority of patients (20/37, 54%) had intracerebral hemorrhagic lesions with a more severe clinical presentation: higher admission rate in intensive care units, 20/20 patients, 100% versus 12/17 patients, 71%, p=0.01; development of the acute respiratory distress syndrome in 20/20 patients, 100% versus 11/17 patients, 65%, p=0.005. Only one patient was positive for SARS-CoV-2 RNA in the cerebrospinal fluid. CONCLUSION: Patients with severe COVID-19 and without ischemic infarcts had a wide range of neurologic manifestations that were be associated with abnormal brain MRIs. Eight distinctive neuroradiological patterns were described.