This is important to anesthesia since we often make pts unconscious.
NEJM Journal Watch
Anthony L. Komaroff, MD, reviewing
MRI scans from before and after COVID-19 diagnosis show adverse brain changes.
Brain imaging studies in people with COVID-19 typically have been small, cases have not been matched carefully to controls, medical history has not been considered, and most importantly, no brain imaging from before COVID-19 diagnoses has been available for comparison.
A new study from the U.K. Biobank overcomes all these deficiencies. Two magnetic resonance imaging (MRI) scans and cognitive testing were performed on people as part of a longitudinal population study that predated the COVID-19 pandemic. In 401 people, positive tests for SARS-CoV-2 occurred between the two MRIs (during the first 18 months of the pandemic); second MRI scans were performed an average of 141 days after positive SARS-CoV-2 tests in this group. These 401 cases were compared with 384 controls — matched to cases by age, sex, ethnicity, pre-COVID health status, and socioeconomic status — who underwent two MRI scans but had negative SARS-CoV-2 tests. Only 4% of case patients with COVID-19 had been hospitalized.
Compared with controls, people with COVID-19 had more reduction in gray matter thickness in the orbitofrontal cortex and parahippocampal gyrus, more tissue damage in regions connected to the olfactory cortex, greater reduction in global brain size, and greater cognitive decline. Similar changes were not seen in a small group of participants who had developed non-COVID pneumonias between their two scans.
This study, combined with recent studies of SARS-CoV-2 infection of primates (NEJM JW Gen Med Jun 1 2022 and Nat Commun 2022; 13:1745) provides strong evidence that even mild COVID-19 can be associated with brain changes. We don’t know how durable these changes might be, whether they contribute to the syndrome of “long COVID,” or if they will progress to dementia in some people.
Douaud G et al. SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature 2022 Apr 28; 604:697.
Gollub RL. Brain changes after COVID revealed by imaging. Nature 2022 Apr 28; 604:633.
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