Can Getting COVID Shrink Your Brain?
March 11, 2022
Empirical evidence is beginning to pour in to help answer questions surrounding Long COVID. In an article, published this week in Nature, researchers studied changes in brain structure following a SARS-CoV-2 infection. What they found suggests that COVID-19 may have the ability to damage the brain, potentially causing long-term deleterious effects. The authors hypothesized that these structural changes could lead to long-term health problems such as inflammation of the nervous system, cognitive decline, and loss of smell.
The study population included 401 COVID-infected participants and 384 controls from the United Kingdom, aged 51-81. In addition to the larger cognitive decline observed in the COVID-infected population, the three major structural differences found were:
- “greater reduction in grey matter thickness and tissue-contrast in the orbitofrontal cortex and parahippocampal gyrus
- greater changes in markers of tissue damage in regions functionally-connected to the primary olfactory cortex
- greater reduction in global brain size.”
These brain regions are primarily in the limbic system, which is mainly responsible for facilitating memory storage and retrieval, establishing emotional states, and linking the conscious, intellectual functions of the cerebral cortex with the unconscious, autonomic functions of the brain stem. It was unsurprising for the researchers to also discover a loss of grey matter in the olfactory-related brain regions due to the hallmark degenerative spread of the coronavirus through olfactory pathways, often leading to anosmia (loss of smell).
Additional follow-up is necessary to determine whether these harmful changes can be reversed or whether these effects will become chronic.