5 ms·

yes and no. it is somewhat alarmist as the olfactory bulb is anatomically part of the brain and is responsible for initial transmission of the olfactory signals

yes and no. it is somewhat alarmist as the olfactory bulb is anatomically part of the brain and is responsible for initial transmission of the olfactory signals for further processing in the amygdala. it essentially completes the circuit between the olfactory neurons and the amygdala. if the research shows that the amygdala has been damaged, then i'd feel much more comfortable with alarmist "brain damage" headline. even so, the damage itself is devastating. my daughter and wife both suffer from covid-related parosmia. my daughter has dealt with it for ~18 months now and has given up hope of ever getting to enjoy tastes she once loved.

ModernMech 5y ago
I'm really sorry for your family. This is part of the reason I don't even want to catch Covid. In 2020 my sister lost her sense of smell t Covid, and it seems to have permanently altered her sense of taste. What else but damage to the brain could do that? To this day food she used to love have been corrupted. She can't describe it, but the closest she has articulated to me is that certain things things "taste the way cigarettes smell." As a result, she has had trouble eating and has lost a lot of weight (not in the way you want to lose weight). I get really upset when people dismiss long covid as some sort of hysteria. Even if that were true, the impacts are real, and it's not a joke or something to be minimized and dismissed.
- timr 5y ago
  > What else but damage to the brain could do that? Damage to the olfactory epithelia. That is what this paper is describing.
  - djmips 5y ago
    I think that was their point. ^
  - shkkmo 5y ago
    This paper describes damage to the axons in the olfactory bulb and tract. While their olfactory neurons have their cell bodies in the epithelial, their axons extend through the tract into the bulb. Thus the damage appears to not be to receptors or support cells in the epithalia / nose but to axons in bulb / brain.
    - timr 5y ago
      > Thus the damage appears to not be to receptors or support cells in the epithalia / nose but to axons in bulb / brain. No. From the paper: > Consistent with findings reported by other groups,16,19 this study also did not find evidence of viral infection in olfactory bulb from most patients with COVID-19. Therefore, the axon and microvascular pathology in olfactory bulb and olfactory tract were most likely not caused by direct viral injury. Moreover: > this study did not find a strong association between olfactory endothelial injury and disease severity, suggesting that local inflammation in the upper respiratory tract may be sufficient to cause endothelial and axonal damage in the olfactory pathway. I'm not an expert in the microanatomy of the olfactory pathway so I'm not going to debate the location of the samples, but the authors are explicit that your interpretation is incorrect. It's not the neurons themselves, it's some inflammatory process external to the neurons that is causing damage. This has clear implications for the level of panic people are bringing to this conversation. A virus that can infect neurons (e.g. rabies, herpes) can cause damage by moving within the nerves themselves. This virus does not appear to do that, and instead causes local inflammation that indirectly influences the neurons. Debating whether or not this is "brain damage" is academic; most people in this conversation are leaping to wild conclusions about the virus "infecting the brain". This is not supported.
      - somewhereoutth 5y ago
        I think the alarm was over brain damage - brain infection would be a deeper level of horror!
        timr 5y ago
        You can rest assured that this paper shows neither.
      - shkkmo 5y ago
        > the authors are explicit that your interpretation is incorrect. It's not the neurons themselves, it's some inflammatory process external to the neurons that is causing damage. I never claimed that infection of the neurons caused the damage. That is a strawman you created. What I said is that there was damage to axons in the olfactory bulb, which is part of the brain. If there are people leaping to wild conclusions, why not respond to them rather than trying to foist their views off on me?
- nradov 5y ago
  Regardless of what you want, you will almost certainly catch a SARS-CoV-2 infection eventually (and perhaps multiple times). The virus is endemic and highly contagious so avoiding it is impractical. You might have already been infected without knowing it because many carriers never develop clinical COVID-19 symptoms. Fortunately the vaccines and other treatments are pretty effective at preventing deaths. https://www.medpagetoday.com/opinion/vinay-prasad/94646 https://www.medpagetoday.com/opinion/vinay-prasad/94646 Most any serious viral infection can cause post-viral fatigue syndrome. We've known that for decades and this virus is no different. https://pubmed.ncbi.nlm.nih.gov/3063394/ https://pubmed.ncbi.nlm.nih.gov/3063394/
  - dv_dt 5y ago
    There are a populations of experts that promulgate that view. There is another population of experts which strongly disagree with the assessment of inevitability. I gravitate towards those that say something can be done; that we have both the science and the ability to do it, though I'd say we do have a lot of people with a lot of power that want to tell us to give up on the precautionary principle.
    - nradov 5y ago
      Which specific experts claim that it will be feasible to avoid a highly contagious respiratory virus for decades? That seems implausible based on what we now about viral transmission. The virus will be around forever, and all it needs is one mistake or a bit of bad luck.
      - dv_dt 5y ago
        We have avoided widespread measles outbreaks for decades
        nradov 5y ago
        So what? That's a total non sequitur. The measles vaccine is highly effective at preventing infection and transmission. That situation doesn't obtain with SARS-CoV-2. The vaccines are pretty good at preventing deaths but they have only a marginal and temporary effect on preventing infection and transmission. For the foreseeable future, every time you interact with another person (or certain other mammal species) there is a significant risk they will transmit the virus to you. That is our reality and wishful thinking won't change it. Instead of trying to avoid infection and most likely failing, a more productive approach is to focus on reducing the risks of a bad outcome when you inevitably do get infected. For most people that means getting vaccinated plus resolving any major risk factor conditions such as obesity, type-2 diabetes, and hypovitaminosis D. And you didn't answer the question. Which specific "experts" claim it will be possible to avoid infection?
hypertele-Xii 5y ago
- histriosum 5y ago
  You may want to try some empathy. Losing one of the primary senses is certainly a devastating loss, even though it is not mortal, as you point out. Death is not the only result that qualifies as devastating.
  - hypertele-Xii 5y ago
    Facts do not care about your emotions. Words have meaning. On a devastation scale of 1-10 losing your sense of smell is like barely a 2.

ModernMech 5y ago

I'm really sorry for your family. This is part of the reason I don't even want to catch Covid. In 2020 my sister lost her sense of smell t Covid, and it seems to have permanently altered her sense of taste. What else but damage to the brain could do that? To this day food she used to love have been corrupted. She can't describe it, but the closest she has articulated to me is that certain things things "taste the way cigarettes smell." As a result, she has had trouble eating and has lost a lot of weight (not in the way you want to lose weight). I get really upset when people dismiss long covid as some sort of hysteria. Even if that were true, the impacts are real, and it's not a joke or something to be minimized and dismissed.

timr 5y ago
> What else but damage to the brain could do that? Damage to the olfactory epithelia. That is what this paper is describing.
- djmips 5y ago
  I think that was their point. ^
- shkkmo 5y ago
  This paper describes damage to the axons in the olfactory bulb and tract. While their olfactory neurons have their cell bodies in the epithelial, their axons extend through the tract into the bulb. Thus the damage appears to not be to receptors or support cells in the epithalia / nose but to axons in bulb / brain.
  - timr 5y ago
    > Thus the damage appears to not be to receptors or support cells in the epithalia / nose but to axons in bulb / brain. No. From the paper: > Consistent with findings reported by other groups,16,19 this study also did not find evidence of viral infection in olfactory bulb from most patients with COVID-19. Therefore, the axon and microvascular pathology in olfactory bulb and olfactory tract were most likely not caused by direct viral injury. Moreover: > this study did not find a strong association between olfactory endothelial injury and disease severity, suggesting that local inflammation in the upper respiratory tract may be sufficient to cause endothelial and axonal damage in the olfactory pathway. I'm not an expert in the microanatomy of the olfactory pathway so I'm not going to debate the location of the samples, but the authors are explicit that your interpretation is incorrect. It's not the neurons themselves, it's some inflammatory process external to the neurons that is causing damage. This has clear implications for the level of panic people are bringing to this conversation. A virus that can infect neurons (e.g. rabies, herpes) can cause damage by moving within the nerves themselves. This virus does not appear to do that, and instead causes local inflammation that indirectly influences the neurons. Debating whether or not this is "brain damage" is academic; most people in this conversation are leaping to wild conclusions about the virus "infecting the brain". This is not supported.
    - somewhereoutth 5y ago
      I think the alarm was over brain damage - brain infection would be a deeper level of horror!
      - timr 5y ago
        You can rest assured that this paper shows neither.
    - shkkmo 5y ago
      > the authors are explicit that your interpretation is incorrect. It's not the neurons themselves, it's some inflammatory process external to the neurons that is causing damage. I never claimed that infection of the neurons caused the damage. That is a strawman you created. What I said is that there was damage to axons in the olfactory bulb, which is part of the brain. If there are people leaping to wild conclusions, why not respond to them rather than trying to foist their views off on me?
nradov 5y ago
Regardless of what you want, you will almost certainly catch a SARS-CoV-2 infection eventually (and perhaps multiple times). The virus is endemic and highly contagious so avoiding it is impractical. You might have already been infected without knowing it because many carriers never develop clinical COVID-19 symptoms. Fortunately the vaccines and other treatments are pretty effective at preventing deaths. https://www.medpagetoday.com/opinion/vinay-prasad/94646 https://www.medpagetoday.com/opinion/vinay-prasad/94646 Most any serious viral infection can cause post-viral fatigue syndrome. We've known that for decades and this virus is no different. https://pubmed.ncbi.nlm.nih.gov/3063394/ https://pubmed.ncbi.nlm.nih.gov/3063394/
- dv_dt 5y ago
  There are a populations of experts that promulgate that view. There is another population of experts which strongly disagree with the assessment of inevitability. I gravitate towards those that say something can be done; that we have both the science and the ability to do it, though I'd say we do have a lot of people with a lot of power that want to tell us to give up on the precautionary principle.
  - nradov 5y ago
    Which specific experts claim that it will be feasible to avoid a highly contagious respiratory virus for decades? That seems implausible based on what we now about viral transmission. The virus will be around forever, and all it needs is one mistake or a bit of bad luck.
    - dv_dt 5y ago
      We have avoided widespread measles outbreaks for decades
      - nradov 5y ago
        So what? That's a total non sequitur. The measles vaccine is highly effective at preventing infection and transmission. That situation doesn't obtain with SARS-CoV-2. The vaccines are pretty good at preventing deaths but they have only a marginal and temporary effect on preventing infection and transmission. For the foreseeable future, every time you interact with another person (or certain other mammal species) there is a significant risk they will transmit the virus to you. That is our reality and wishful thinking won't change it. Instead of trying to avoid infection and most likely failing, a more productive approach is to focus on reducing the risks of a bad outcome when you inevitably do get infected. For most people that means getting vaccinated plus resolving any major risk factor conditions such as obesity, type-2 diabetes, and hypovitaminosis D. And you didn't answer the question. Which specific "experts" claim it will be possible to avoid infection?

hypertele-Xii 5y ago

histriosum 5y ago
You may want to try some empathy. Losing one of the primary senses is certainly a devastating loss, even though it is not mortal, as you point out. Death is not the only result that qualifies as devastating.
- hypertele-Xii 5y ago
  Facts do not care about your emotions. Words have meaning. On a devastation scale of 1-10 losing your sense of smell is like barely a 2.