26th Jun 2020
26th Jun 2020
Curated by Endre Szvetnik
There is growing evidence that COVID-19 is causing brain damage in patients and that the SARS-CoV-2 virus behind the disease may itself attack the central nervous system.
A small proportion of patients in intensive care units (ICU) may appear confused, in a state of delirium or even develop psychosis. In situations where their blood oxygen saturation levels are low, they might not gasp for air, suggesting that the signals from the brain regulating breathing are disrupted. A new UK study is a first national analysis of 125 COVID-19 patients who displayed neurological complications and whose data was gathered in April 2020. Before this, only very small studies existed with findings from a few patients in China, Japan and Italy, where the SARS-CoV-2 virus was discovered in a patient’s brain. From the cases reported by the UK study, 31% of hospitalised patients with neurological complications had altered mental status, 45% experienced strokes and 41% sustained some sort of brain damage. The researchers have also found that a significantly higher proportion of younger patients displayed serious alteration in their mental status.
Does this mean the virus can directly attack the brain and central nervous system? Scientists are debating whether the illness (COVID-19) may indirectly cause brain damage or the virus causing it (SARS-CoV-2) may be targeting the brain. Brain damage during COVID-19 can be provoked by the exaggerated immune reaction, known as a cytokine storm, which may cause brain swelling. Another way the illness can damage the brain is by causing blood clotting, which may lead to strokes by blocking the flow of blood and oxygen into the brain. (A large proportion of COVID-19 patients in intensive care have experienced blood clotting and strokes – read more about it in our earlier FAQ answer). Studies about other pandemic-causing coronaviruses (SARS-CoV in 2003 and MERS-CoV in 2012) suggested they were able to invade the central nervous system, cause neurological complications and brain damage. For researchers, the next important question is if the virus can breach the ‘blood-brain barrier’, formed by closely packed cells lining the blood vessels in the brain to protect it from infections. At the moment there is not sufficient evidence to say that coronaviruses infecting humans have done this.
Here is the current state of science on a Sparrho pinboard. NB: The pinboard contains research papers that have not been peer-reviewed yet, meaning that they have not gone through the standard scientific validation process yet.
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