This study shows links between Long COVID’s neurological effects, including brain fog and cognitive decline, and brain blood vessel integrity, offering hope for new treatments and diagnostic methods.
https://www.nature.com/articles/s41593-024-01576-9 (open access)
Bringing in a medical perspective since there is a lot of subtle misunderstanding in the comments section:
The source study is not referring to “brain bleeding” or “mini strokes” as a cause of long COVID—the results point more towards a breakdown of the integrity of the blood brain barrier and maybe micro vascular ischemia.
You can essentially think of your central nervous system (brain and spinal cord) as being surrounded by a very selective security system called the Blood Brain Barrier (BBB). The BBB exists to prevent certain chemicals and cell signaling molecules from entering the central nervous system and messing things up. Neurons and many of the cells that support neurons do not regenerate and tolerate stress as well as other parts of the body, which is why the BBB is so important. Through the various assays the primary authors used it seems like in the setting of long COVID there is a breakdown of the BBB—it starts letting things in and out that it shouldn’t be. This leads to inflammation and damage in the brain which likely results in immediate decreased processing ability and also long-term damage (which further leads to decreased processing ability). One of the components which “leaks” in this setting of BBB breakdown are components of the coagulation cascade (the things that make blood clot) which may potentiate small areas of clotting and decreased blood flow (a thing we called micro vascular ischemia—like an ischemic stroke but in very small capillaries). This entire mechanism is similar to (but very different in nuance) “leaky gut syndrome,” where the gut endothelium starts to break down and cause inflammation. I put that out there since leaky gut is gaining more popular understanding these days and may be more familiar for some folks.
As of now there is no available treatment that restores the endothelial integrity of the BBB. Off of the top of my head this study may suggest that more treatments to modulate the inflammsome (roughly—the amount of inflammation in your body) could be beneficial—which sort of tracks since there is some scattered evidence that high dose Omega-3’s help long COVID.
Not exactly—although an MRI w/wout contrast may show some microvascular ischemia or cortical volume loss. Based on the study there may be some clues from secondary inflammatory markers, but those aren’t specific (other things can elevate them beyond long COVID).
I think this will likely remain a clinical diagnosis for several years until we understand more.
Would you say that the layman’s metaphor for this is like the brain suddenly living in a drafty house?
I’ve been waiting since 2021 for my sense of smell and taste to come back :(
Anecdotal but several of my friends claimed that psilocybin therapy restored their sense of smell.
That is interesting. Psilocybin has been shown to grow new brain neural pathways. It does seems plausible.
Apologies if you’ve already tried this or something similar, it doesn’t work for everyone, but I got mine back by using essential oils to retrain [edited as my phone autocorrected to ‘restrain’] my olfactory system. After over a year of my food tasting like trash, or like it was off, and a dangerous incident (with a trip to A&E) where my brain fog meant I left an unlit gas oven on all night and couldn’t smell it until I’d already got carbon monoxide poisoning (thankfully mild and temporary), I regained my smell and taste in about a week. Here’s an article about it, it links to a charity that works in the field of loss of smell : https://www.saga.co.uk/magazine/health-wellbeing/treatments/smell-training-for-anosmia
Edit: if the down votes are because people think this is alternative medicine or woo, it isn’t, it’s a technique used in conventional medicine clinics. Try reading before you down vote.
To educate downvoters: Yes, “essential oil” health advice is a common bullshit indicator! But! They’re the standard pharmaceutical for this task, found in kits like this one used to train food and beverage scientists. Any diverse set of strong familiar smells can work.
I worked in a related field and got my ass kicked by long COVID shortly after the start of the pandemic. This is a good starter on the biology involved, a journal article from Nature, unpaywalled: https://web.archive.org/web/20220623072436/https://www.nature.com/articles/d41586-022-01628-9
Treating anosmia from brain damage is the same for post-COVID as for a car accident or getting gassed in WWI: you diligently breathe in the olfactory training kit and try to vividly remember those smells.
Pull quote: “Sometimes, the sense of smell recovers spontaneously after injury. The olfactory nerve is the only cranial nerve that can repair itself when damaged, and olfactory sensory neurons — cells in the upper part of the nose that recognize different odorant molecules — renew themselves periodically throughout life.“
edit to add, extreme sympathies to anyone who has found themselves experiencing this!
e2: corrected link
I got COVID twice, and both times I lost my sense of smell. The first time it lasted 3 days, and the second time, the total loss was only for half a day. Both times, one of the first smells I was able to detect was the vinegar in salt&vinegar chips. It’s a strong smell that seemed to “pierce through” the block.
regarding your edit there, I guess most people stopped reading at ‘essential oils’ without knowing where this was going.
this is one (the only?) actual medical use for these things - their main thing is that they smell in a certain way that is consistent, so you use them to retrain your sense of smell. that’s it. no taking internally or applying to skin or whatever. just take the stopper off the wee bottle, sniff and repeat for as many bottles as you can be arsed.
when I had covid-19, I didn’t have so well defined scents on hand, but I did have several colognes I could sniff, and I knew fairly well how they were supposed to smell and could use those to gauge my senses. fun times, they were…
I only realised I’d lost my smell completely when I smelled some perfume and thought it must be off, because it smelled of nothing. Then I realised that my other perfumes were ‘off’, and then went around my home smelling random things and finally realised it was me. I think it was the effect on my taste that was the hardest thing though. Onions and garlic especially made everything taste horrible.
Try reading before you down vote.
Speaking only for myself, what really threw me off was the following:
Apologies if you’ve already tried this or something similar, it doesn’t work for everyone, but I got mine back by using essential oils to restrain [emphasis mine] my olfactory system.
I think that if I’d realized that you meant to say “retrain” here instead of “restrain”, I would not have been so quick to initially dismiss it as obviously nonsense.
Yeah that’s my phone autocorrecting. I’m not sure why anyone would think I meant ‘restrain’, but oh well. I’ll edit, thanks for pointing it out.
Sharon Amos has written about gardening for Saga Magazine and The Guardian, among others. She is the author of Plants for Free and Great Plants for Tough Places.
Sure buddy.
Oh no, someone who writes about gardening!! In a magazine for the elderly!!Look, it was just the first article I could find while I was in the middle of baking, that wasn’t an American health and wellbeing website. I’m not American so I don’t know those websites and I don’t know what they all are. I just wanted to help the person I was replying to. The article links to the charity that has done loads of research into it. Yes I could have found a better link and fucking hell I wish I hadn’t bothered even commenting now.
Holy shit I had a mild case of COVID with headaches as my only symptom. I then had long COVID and couldn’t think straight, forgot words all the time, had trouble finishing sentences. It’s terrifying to think this is why that was happening but it tracks because every time my feet got cold during that same time period one of my toes swelled up. Probably the same thing happening in my foot and my brain.
Oh wow I’ve been blaming alcohol abuse on brain fog. I quit drinking last year but still can’t remember words all the time, same with finishing sentences. Struggling with being articulate all the time. And this all started during covid.
That could be long COVID but it could also unfortunately be the after effects of heavy drinking. Did your brain issues start after you had COVID?
This is terrifying. I am 8 weeks in after testing positive. A blood exam reveal no more viral or bacterial infection but I still experience some anxiety and brain fog, today was one of those days (yesterday was an awesome day on the other hand).
I get cold hands all the time when I am starting to feel unwell.
So this is actually pretty close to what a lot of people thought was going on: mini strokes.
Can it be treated? Does it heal?
Anecdotally speaking I had covid a few months before vaccination became available (yay) and had horrible brain fog. I forgot a lot of words and really struggled with finishing sentences, things like that. It did improve but it took about a year. At the same time one of my toes kept swelling up every time my feet got cold and that stopped around the same time my ability to think improved.
Thanks for sharing a hopeful anecdote about long COVID, they’re few and far between. I’m glad you got better.
Thank you so much. It was a scary time because I felt like my brain was never going to work again.
