Microvascular Injury of Brain, Olfactory Bulbs Seen in COVID-19
Multifocal microvascular injury in the brain and olfactory bulbs is another possible adverse outcome from COVID-19, new research suggests. Postmortem MRI brain scans of 13 patients who died from COVID-19 showed abnormalities in 10 of the participants. Of these, 9 showed punctate hyperintensities, "which represented areas of microvascular injury and fibrinogen leakage," the investigators report. Immunostaining also showed a thinning of the basal lamina in 5 of these patients. Further analyses showed punctate hypointensities linked to congested blood vessels in 10 patients. These areas were "interpreted as microhemorrhages," the researchers note.
@sampriti The investigators examined brains from a convenience sample of 19 patients (mean age, 50 years), all of whom died from COVID-19 between March and July 2020.
An 11.7-Tesla scanner was used to obtain magnetic resonance microscopy images for 13 of the patients. In order to scan the olfactory bulb, the scanner was set at a resolution of 25 µm; for the brain, it was set at 100 µm. Chromogenic immunostaining was used to assess brain abnormalities found in 10 of the patients. Multiplex fluorescence imaging was also used for some of the patients.