Not “just” a lung disease

There’s a lot of terrible things about the coronavirus. We now know that it’s not just a pulmonary disease. It is also linked with cardiac problems and strokes. But there’s another potential problem that hasn’t yet attracted much attention. It’s the neurological impacts of the virus.

We used to think that the virus led to lung problems and, even if they were serious, that’s where it stayed. But there’s mounting evidence that this is only part of the story. Another part is that what causes the sudden breathing distress might be not the lungs themselves but damage to the respiratory areas of the brain in the brainstem. In other words, there are neurological impacts too. The virus impacts the brain.

Some of these impacts can be severe. They include, inter alia, brain inflammation, hallucinations, seizures, cognitive deficits. That’s not good.

But there’s one that is particularly worrying that the media haven’t caught up with yet. It’s the well-known symptom of the loss of smell and taste that often occurs with those who have the virus.

Here’s the especial warning sign. It’s that loss of smell and taste is also experienced by many sufferers of Alzheimer’s. So much so that some researchers are trying to develop a test for Alzheimer’s based on this very fact.

In the brain too

Some of this information has been around since the SARS epidemic (“New Study Shows SARS Can Infect Brain Tissue”). Research in China led to the discovery that SARS virus was found in brain tissues of victims. That research also showed that this could lead to brain damage and other neurological symptoms that could lead to death. But since SARS was seen as a Chinese problem, no-one took much notice.

But as we know, covid-19 is just a kissing cousin of SARS. It’s basically the same organism. And now we’ve got cases in the hundreds of thousands. How many of these also have neurological impacts? We know that many have lost their sense of smell and taste although we don’t know if that is temporary or permanent. But it suggests some of the same processes that occur in Alzheimer’s are already taking place in cases of coronavirus.

Too much sugar again?

But there are other signs that covid-19 and dementia are also linked. We know that, other than taste and smell, there are other common factors in morbidity in covid-19 and Alzheimer’s. These factors include obesity, diabetes, metabolic disease generally and atherosclerosis (“Metabolism and Memory: Obesity, Diabetes, and Dementia”).. Once we get to have a closer look there’s a lot more in common going on and one would first think. The perception that covid-19 is just a lung disease has blinded us to the common neurological and metabolic impacts.

There are many neurological diseases that cause dementia of some sort or another and it’s impossible at this stage to surmise what is going on here. But we do know for sure that there are neurological impacts of the virus and that some of them resemble those seen in cases of Alzheimer’s. There could be potential for the virus to lead to neurological impacts that lead to dementia. Maybe these impacts only appear years later. We don’t know – yet.

Not to mention Alzheimer’s

I’ve written several posts on Alzheimer’s and the tragic lack of any meaningful progress (“We urgently need a Manhattan Project for Alzheimer's!”; “Does high protein cause heart disease – and Alzheimer’s?”). It’s at least possible that covid-19 opens up a new research route to figure out what’s going on. That’s the silver lining, if indeed that is one.

But the dark side is that covid-19 might leave another legacy, namely increasing even further the spread of dementia, not just amongst older people, but younger ones also.

It’s not a pretty picture. Maybe I’m being a doom-monger. But better to know your enemy than not. There have been many previously unrecognized impacts of the virus that we hadn’t been aware of, including cardiovascular and kidney disease, both of which are associated with high levels of mortality.

The danger here is that the virus will expose not just another cause of mortality, bad though that might be, but a source of increased chronic neurological disease which, if anything, could be even worse on a social and global level than the short-term mortality.

If indeed the virus does have such untoward consequences, it means that the global spread of dementia will be even faster, bigger and more serious than it already is. The effects will transition from being serious but temporary to tragic and chronic.

Time for another research project here on the neurological impacts of covid-19, I think.