CEREBRAL MICROBLEEDS IN PATIENTS WITH NEUROLOGICAL SYMPTOMS ASSOCIATED WITH COVID-19: DISTRIBUTION AND POSSIBLE PATHOPHYSIOLOGICAL MECHANISMS

ABSTRACT

Cerebral microbleeds (CMB) emerged as a possible complication of COVID-19. We aimed to assess CMB presence, distribution, and potential underlying pathophysiological mechanisms in hospitalised COVID-19 patients. In a cohort of 112 COVID-19 patients with neurological symptoms admitted to the Geneva University Hospital between March 2020 and May 2021, we assessed CMB distribution, and associations with clinical/ radiological variables. Neuroimaging was performed on a 1.5 T MRI with susceptibility-weighted images, 3D time-of-flight angiography, and 3D-contrast-enhanced fat-saturated T1 black blood VISTA sequences. Two neurologists rated CMB using the Microbleed Anatomic Rating Scale and white matter hyperintensities using the Age-Related White Matter Changes score. 53 patients (47.0%) had CMB;in 45.3% of cases, CMB were found in lobar regions with a predilection for temporal (58.3%) and frontal (29.2%) lobes. Deep CMB were present in 18.9%, with corpus callosum CMB found in 15.0%, in 35.9% CMB distribution was mixed. CMB presence was not related to intubation, pulmonary involvement, nor to radiologic signs of endothelitis. Patients with CMB were more likely to have a higher burden of white matter hyperintensities (OR 1.13, p=0.005, 95% CI 1.03- 1.24), to have hypertension as a comorbidity (OR= 2.34, p= 0.04, 95% CI 1.04 - 5.30) and to suffer from an acute stroke during hospitalisation (OR 3.50 p= 0.012, 95% CI1.31-9.18). In our sample, COVID-19 patients with neurological symptoms had a high burden of CMB. Their distribution suggests that they may be related to cardiovascular risk factors and cerebral amyloid angiopathy. CMB were also associated with an increased risk of acute stroke.