The mysterious flow of fluid in the brain

Since I was a child I have been very susceptible to exertion headaches and indeed coughing/sneezing can easily trigger this. They last from a couple of hours to the entire day, being gone when I wake up. The pain is not as bad if I lie down. I'm personally convinced it is directly linked to the pressure of my cerebrospinal fluid.

MRI has of course revealed nothing. Syringomyelia was not supposed to be hereditary (father) and nothing has been detected, but there is a chance that the cavity is so small/narrow that it blocks shut when I lie down: pain subsides, nothing is there to be seen when I'm in the machine. Vertical MRI, anyone?

The "valsalva maneuver" has a 100% success rate of triggering symptoms, and recently (some years) I have begun to observe a high-pitched sucking sound, consistent duration of about a second, originating from somewhere between my right ear lobe and spine. The sound is not uncomfortably loud but could be missed if I was listening to music or having a conversation. I think I have only ever observed the sound when in a sitting position. When detected, the sound might be accompanied with a physical sensation, but it is so minimal that I'm unsure if I'm imagining it.

It's just one of those things at this point.

My late wife had a brain tumor that put pressure on the sinus veins, causing increased cranial pressure that affected her eyesight.

We learned through the process that many people have significant occlusions in those veins - some 100% on one side. It’s no problem for most people… and until recently there was little to do if there was a problem.

If you ever have a reason to get a contrast MRI of your brain, do it!

I also have those (along with sneezing). I cannot do anything for the next 5-10 minutes until it goes away. For me it's simply (but maybe not only, who knows when reading the sibling comments) allergies. I don't have allergy symptoms like cough or watery eyes, etc. But somehow my sinuses get "full" and pressure builds up inside. If I take antihistaminic almost daily then my sinuses (mostly one side) don't fill up and I can't cough or sneeze without fear. Since you went to a doctor they probably ruled that out, but maybe not, and it checks out with their "it's probably mechanical" hunch.

The cough headache appearing right after pregnancy is suspicious. Did you get an epidural? I think they are finding that CSF leaks (which can be a complication of lumbar punctures and epidurals) are underdiagnosed. I wonder whether a small leak might manifest as a headache triggered by coughing and bending over.

Yes. I think scientists discovered within the last 10ish years that the brain has a lymphatic system at all. That kindof blew my mind, they they've only just discovered an anatomical feature of the brain? I find that kindof crazy, like, were they even looking?

> In living things, all the processes seem to mesh so it's plausible that even this fluid movement has some impact on cognition.

That sounds bang-on accurate, friend. That also makes the importance of exercise more obvious and subtle to me, walking being most gentle on the body but also requiring at least 30 minutes to really be "exercise". And, then, how good is the air being cycled in on those breaths. I imagine it's damn near impossible to find good air for lots of people who don't have a good tree-filled park close by. I have both seen the morning "green air cloud" hanging over Istanbul on the flight in, as well as the amount of smog on the ground in the morning. Returning to the US the first time visiting Turkiye I was immediately struck by the amount of greenery on the east coast here in the States.

Some animals get most if not all of their sleep through microsleep [1]. So whatever mechanism "refreshes" the brain, it can work on short time scales. The switch in brain firing dynamics from wake to sleep (NREM) is very fast -- on the order of one to a few seconds. People in team Nedergaard argue that it is the rhythmic neuronal activity during sleep that promotes fluid flow (though to be fair, some argue its arterial pressure). So their answer to your question would be yes, that should be enough time to enhance fluid flow (fluid is flowing all the time, the question debated by scientists is, whether is it being enhanced during sleep).

[1] https://www.science.org/doi/10.1126/science.adh0771

Agreed. For me turning over in bed during a lie-in also feels immensely refreshing and I now do it quite consciously. It may be nothing to do with cerebrospinal fluid but I do like to attribute it to the brain's wash cycle.

I've felt my brain flush, dunno if anyone else has.

Reading the core paper discussed in the article, along with all its context, will take ~hours. This article is a great 5-minute update on the latest research with a well written primer on the topic

>could read papers if they want but choose not to

Journals are expensive.

>catering to your level of literacy?

Lowering the cognitive effort required to acquire the new information makes it more broadly available. Both to people that couldn't comprehend the source material, and to those that could, but don't want to spend the cognitive energy.

I can understand the argument that we should avoid dumbing down our media, but this is a weird battle to pick. Go throw stones at youtube shorts if you're worried about modern media liquifying humanity's frontal cortex.