4 ms·

Before you can investigate the causes of an illness, you have to define it. Otherwise, you’re chasing an ever-shifting cloud of ambiguous symptoms, any of which

by timr 4mo ago

Before you can investigate the causes of an illness, you have to define it. Otherwise, you’re chasing an ever-shifting cloud of ambiguous symptoms, any of which could have different causes. The article opens with this admission, so I’m not stating anything new here. The problem with “Long Covid” as it exists today is that there’s no such definition. Literally anyone who had Covid once and feels bad today (and quite a few people who never had a confirmed case at all) includes their set of symptoms in the communal diagnosis. Thus, if you dig into these studies, you always find that the syndrome is a wide-ranging and variable constellation of symptoms, making it impossible for a study to have any systematic legitimacy. Moreover, the results of any particular study are more strongly influenced by the inclusion criterion (if there even is one) than by any other factor. It’s perfectly possible to evaluate treatments in this situation, and would be a better use of resources - pick symptoms, make an inclusion criteria, and run a randomized trial of existing drugs or therapies. But this is likely to fail, and it’s much, much easier to write papers with unprovable theories and retrospective analysis.

dyauspitr 4mo ago
Sometimes the symptoms are so ambiguous that it is hard to nail anything down. It’s the same thing with Lymes disease, which is definitely a real thing, but there aren’t good, reliable tests for it. It takes a long time to manifest and the symptoms vary wildly from person to person.
- kranke155 4mo ago
  There are increasingly positive markers - autonomic dysfunction in previously healthy people, measurable small fiber neuropathy, and auto immune dysfunction in largely unmapped parts of the immune system.
- Aurornis 4mo ago
  > It’s the same thing with Lymes disease, which is definitely a real thing, but there aren’t good, reliable tests for it There are actually good, reliable tests for it. However Lyme disease (not Lymes disease) became an alternative medicine explanation for everything vague and many people became obsessed with thinking they had it based on vague symptoms like fatigue. When they couldn’t get positive test results to confirm their belief, the Lyme disease online communities established the idea that the tests cannot detect their version of the disease. It’s a belief that allows anyone to diagnose with Lyme disease in a completely unprovable way. > and the symptoms vary wildly from person to person. This belief is an unfortunate result of the online Lyme communities encouraging everyone with any unexplained symptoms to believe it’s caused by Lyme disease that can’t be detected. When the disease becomes redefined as being untestable and causing wildly different symptoms in everyone, it becomes impossible to say that anyone doesn’t have it. If you have any vague symptoms like feeling tired, a Lyme disease community will encourage you do believe that it’s caused by an undetectable case of Lyme disease. There is a lot of strong evidence that these patients do not have Lyme disease, but they’re always good at coming up with another reason why they have it but it can’t be detected in them specifically
setopt 4mo ago
Interesting. Someone should (or maybe have?) run a cluster analysis on the symptoms to define more specific subgroups. But I suppose getting access to the required health data at that scale is nontrivial?
- timr 4mo ago
  It’s not that hard to get a long list of symptoms for long covid. Just watch this thread as it grows, and you’ll easily find dozens. Things like this end up being a lint trap for people who just feel bad for whatever reason (which is all of us, at various points in our lives!) Nobody likes to be told that their symptoms are idiopathic. Massaging this kind of data (clustering, etc.) is much lower value than finding fixed criteria that define a consistent group of patients who have objectively defined symptoms that cannot be more readily explained by another diagnosis. This is a pre-requisite for any further study. It can be done, but it’s hard, and it tends to lead to criticisms because you end up excluding a large number of people who fervently believe they have the illness, but don’t fit the objective standards. Just for example: it’s not enough to claim that you have “brain fog”. A more valid endpoint might instead attempt to classify people based on standardized tests of thinking. Even that has problems, of course, but if you can just claim that you are fatigued and unable to think clearly, there’s a huge problem of confounding (i.e. maybe your symptoms are caused by something else), let alone the unverified nature of the original claim.
  - kranke155 4mo ago
    Leading research into Long Covid is already doing this. You’re seeing neural and auto immune clusters gathering around certain immune dysfunction and previously rare diagnosis like Small Fiber Neuropathy. Autonomic dysfunction is being measured in young and healthy people also, and that has its own set of objective testing. Everything you are saying is happening. But because the suspicion seems more and more that it’s an auto immune condition of some sort, and that we are only catching the downstream effects as some of the immune dysfunction isn’t mapped yet, we are seeing the clusters that you say emerge - overwhelming numbers of symptoms, relatively incoherent connection. But autonomic dysfunction, small fiber neuropathic and detectable auto immune dysfunction are all known and increasingly mapped positive markers for the condition. Have you read the latest studies ?
lstroud 4mo ago
MCAS is pretty well defined and is associated with it.

by timr 4mo ago

dyauspitr 4mo ago

Sometimes the symptoms are so ambiguous that it is hard to nail anything down. It’s the same thing with Lymes disease, which is definitely a real thing, but there aren’t good, reliable tests for it. It takes a long time to manifest and the symptoms vary wildly from person to person.

kranke155 4mo ago
There are increasingly positive markers - autonomic dysfunction in previously healthy people, measurable small fiber neuropathy, and auto immune dysfunction in largely unmapped parts of the immune system.
Aurornis 4mo ago
> It’s the same thing with Lymes disease, which is definitely a real thing, but there aren’t good, reliable tests for it There are actually good, reliable tests for it. However Lyme disease (not Lymes disease) became an alternative medicine explanation for everything vague and many people became obsessed with thinking they had it based on vague symptoms like fatigue. When they couldn’t get positive test results to confirm their belief, the Lyme disease online communities established the idea that the tests cannot detect their version of the disease. It’s a belief that allows anyone to diagnose with Lyme disease in a completely unprovable way. > and the symptoms vary wildly from person to person. This belief is an unfortunate result of the online Lyme communities encouraging everyone with any unexplained symptoms to believe it’s caused by Lyme disease that can’t be detected. When the disease becomes redefined as being untestable and causing wildly different symptoms in everyone, it becomes impossible to say that anyone doesn’t have it. If you have any vague symptoms like feeling tired, a Lyme disease community will encourage you do believe that it’s caused by an undetectable case of Lyme disease. There is a lot of strong evidence that these patients do not have Lyme disease, but they’re always good at coming up with another reason why they have it but it can’t be detected in them specifically

setopt 4mo ago

Interesting. Someone should (or maybe have?) run a cluster analysis on the symptoms to define more specific subgroups. But I suppose getting access to the required health data at that scale is nontrivial?

timr 4mo ago
It’s not that hard to get a long list of symptoms for long covid. Just watch this thread as it grows, and you’ll easily find dozens. Things like this end up being a lint trap for people who just feel bad for whatever reason (which is all of us, at various points in our lives!) Nobody likes to be told that their symptoms are idiopathic. Massaging this kind of data (clustering, etc.) is much lower value than finding fixed criteria that define a consistent group of patients who have objectively defined symptoms that cannot be more readily explained by another diagnosis. This is a pre-requisite for any further study. It can be done, but it’s hard, and it tends to lead to criticisms because you end up excluding a large number of people who fervently believe they have the illness, but don’t fit the objective standards. Just for example: it’s not enough to claim that you have “brain fog”. A more valid endpoint might instead attempt to classify people based on standardized tests of thinking. Even that has problems, of course, but if you can just claim that you are fatigued and unable to think clearly, there’s a huge problem of confounding (i.e. maybe your symptoms are caused by something else), let alone the unverified nature of the original claim.
- kranke155 4mo ago
  Leading research into Long Covid is already doing this. You’re seeing neural and auto immune clusters gathering around certain immune dysfunction and previously rare diagnosis like Small Fiber Neuropathy. Autonomic dysfunction is being measured in young and healthy people also, and that has its own set of objective testing. Everything you are saying is happening. But because the suspicion seems more and more that it’s an auto immune condition of some sort, and that we are only catching the downstream effects as some of the immune dysfunction isn’t mapped yet, we are seeing the clusters that you say emerge - overwhelming numbers of symptoms, relatively incoherent connection. But autonomic dysfunction, small fiber neuropathic and detectable auto immune dysfunction are all known and increasingly mapped positive markers for the condition. Have you read the latest studies ?

lstroud 4mo ago

MCAS is pretty well defined and is associated with it.