Can COVID-19 Really Cause Memory Loss?
Dispel myths and known facts
From amongst all the serious ways the SARS-COV-2 virus affects our bodies, perhaps the most sinister may be the effects coronavirus has on the functioning of our brain.
It has become increasingly evident that many patients diagnosed with COVID-19 display neurological symptoms, from losing their sense of smell, delirium, and heightened risk of suffering stroke. Then there are the longer-lasting effects on the brain, that can include Myalgic encephalomyelitis (or chronic fatigue syndrome), and Guillain-Barre Syndrome.
These effects can well be caused by direct viral infection in the brain tissue, however growing evidence has suggested that additional indirect actions that are triggered by the virus infecting the epithelial cells and cardiovascular system, or via the immune system and inflammation, cause lasting changes to the nervous system post COVID-19.
In case you or anyone you know has been experiencing any irregularities after COVID-19, this article from one of Delhi’s best neurologists at Aakash Hospital, Dwarka’s best hospital for neurology, can help you.
Our neurologists often question if there could be more COVID-19-related cases of memory deficits or loss that will come to light layer, or could It be behind cognitive decline and dementia cases in the future? Our hospital for COVID in Dwarka has received and treated many cases of coronavirus and many patients have displayed debilitated cognitive function.
The immune system and the brain
Most symptoms we think are cause because of an infection are In fact results of protective responses of our immune system. A running nose from a cold is not a direct effect of the viruses itself but is a result of our immune system’s response to the virus, this happens because of the activation of immune cells called neuro-immune cells, these signal the brain to launch such responses to infection.
These responses that bring changes in brain function and behaviour, can be uncomfortable and halt our everyday lives, but they are highly adaptive and hold great benefits. When we rest when sick, we let the energy-demanding immune response step in and do its thing.
Over and above changing behaviour and altering physiological responses under illness, the specialised immune system in the brain also has other plays to play. Due to recent findings it has become clear that the neuro-immune cells are also necessary for normal memory function, ability to retain thought and normal memory function.
As much as we hate to say it, this also paves a for way for infections like COVID-19 to cause acute neurological symptoms and long-lasting complications for the brain.
Our specialised immune cells get activated when we are ill; and they send out large quantities of inflammatory signals, and modify how they communicate with neurons. This will mean changing
shape, and can cause a chain reaction of sorts where neuronal connections, vital for memory storage; are destroyed by these new shaped cells.
Another type of neuro-immune cell binds itself between neurons as a response to illness and dumps inflammatory signals onto these junctions, effectively stopping any changes in connections between neurons that store our memories.
An immune response to COVID-19 entails a huge relay of inflammatory signals sent out from the brain and the impact of this disease on memory could well be short-term effects on cognitive ability (delirium), as well as long-term changes that may happen to memory, attention and cognition. There is risk of cognitive decline including Alzheimer’s disease.
How can inflammation cause long-lasting effects on memory?
You may us at this time the simple question: if the neuro-immune cells are activated only while we have COVID-19, which is about two weeks, then how can there be long lasting memory loss and risk of cognitive decline?
Our brain and immune system have been evolved to change as a consequence of experience, in order to survive and neutralise danger. In our brain, the changes in connections between neurons allows us to make memories and change behaviour to escape from threats, or seek shelter and food. The immune system’s evolution has fine tuned it to launch an inflammatory response and antibodies are produced against the pathogens.
Yet long-lasting alterations to the brain after illnesses are closely linked to higher risk for age-related cognitive decline and potentially Alzheimer’s disease. The disruptions that are caused by the actions of neuroimmune cells, along with the damage and inflammatory signals can permanently damage memory. This can occur because of irreparable damage to the neuronal connections or even neurons.
The likely link between COVID-19 and memory loss is also based on the outcomes on memory from other illnesses. For example, many patients who have survived heart attacks have reported lasting effects on their cognitive ability, which worsened with age. Sepsis also causes similar cognitive debilitation complications. In animal observations of these diseases, there is a clear impairment of memory, and changes to the neuro-immune and neuronal function that last weeks and months after illness.
It will still be some years before we know if COVID-19 infection directly causes increased risk for cognitive decline or Alzheimer’s disease. But this risk is best decreased through prevention of COVID-19 altogether.