I had a CSF leak repaired by Dr. Schievink at Cedars-Sinai. My diagnosis happened after I had an acute attack of intracranial hypotension shortly following a long and bumpy session of riding mowing. This attack involved a 'worst headache of my life' that was somewhat relieved by being horizontal. Getting to the hospital seemed too painful, so I stuck it out at home and the headache went away. A couple days later I developed a left sixth cranial nerve palsy, which persisted for around two weeks before I finally went to the ER. After a few days in the hospital and tons and tons of tests for infections, MRIs, lumbar punctures, etc, they decided that I had idiopathic hypertrophic pachymeningitis. That was the working diagnosis for about a week, when my neurologist called me back and told me that they thought they had found CSF leaked into the spinal canal, and so they believed I had a CSF leak.
So, the short answer is that diagnosis will be difficult, and there isn't really a test, but MRI with gadolinium contrast will show enhancement of the dura, and hopefully someone looking at it can see a leak if it is obvious. There are also cases of leaks being caused by a venous fistula, which does not image well.
For what it's worth, I had back-of-head-and-neck headaches intermittently for a while before this, most notably when riding rollercoasters (which I do miss). That is the only long term subtle 'sign' I can remember.
Hope this helps.
Edit: I should also probably add that my case is somewhat weird, caused by a bone malformation in my thoracic spine and difficult to localize with imaging. I had a T1 laminectomy to correct this. However, I'm not sure there are really 'standard' cases, except those that are iatrogenic due to LP or epidural in delivery.
If you don't mind answering, how old were you at the time and what was your proximity to Cedars-Sinai?
I have slight regret with not double booking an appointment with Schievink when he personally called me. For some likely completely unreasonable reason, I feel like Dr. Carroll is a bit better of a choice having had a child with a leak. Had an appt with Carroll a small ways out - was in San Diego for strange reasons at the time - was going to be gone by the date of the appt and have to fly in. Schievink very much thought I had a leak from history and others diagnosis (EDS & POTS) - but thought I may be in better hands with Stanford as I already had an appointment - the main reason I went after Schievink was because I was hoping to be seen before I left SD. For some reason, I made the choice to agree with him and stick with only Carroll.
Anyways... A ton of unfortunate things fell thru with some misscheduling at Stanford, and I'm still on a list to be seen by Carroll :(
While both doctors think it's likely that I have one, which is something they've both said they typically don't say over the phone, either way - I see Dr. Carroll as an absolute hero in these strange times we seem to be living in. As selfish as it sounds, I can only hope that man pioneers research into this for the rest of his life. Being on the receiving end of at least one (possibly two with CSF) medical diagnosis in which there's less quality researchers/surgeons in the Western World than can be counted on one hand, you grow to have very strange ideals as to what's truly important in life.
I was 30 when all of this transpired initally (I had my surgery at the beginning of last September). I actually live quite far away from Cedars, in Illinois, but forwarded my local medical records to Dr. Schievink after a lot of online research. Post-surgery I stayed with a friend from college who lives in Santa Monica, which was an enormous help, but it also wouldn't be so bad to post up in a hotel. From initial inquiries to the surgery took ~2-3 months, which surprised me.
I haven't interacted with Dr. Carroll, but my general impression of Dr. Schievink was very positive. Everyone in the whole process at Cedars was awesome. That said, I do still have some lingering issues recently that superficially seem spine-related, despite being assured that my saga was over. It has definitely been an improvement, though, relative to pre-surgery.
I'm sorry to hear to you're going through all of this, but there really is light at the end of the tunnel, and I hope you get there sooner than later.
If you have other questions, you can email me at my HN handle @ gmail and I will try to help as I can.
Unfortunately, math doesn't really permit this type of truth: if your axioms are strong enough to prove general statements about arithmetic, there is no effective procedure to determine whether an arbitrary proof follows from those axioms.
Actually, I thought the post you were responding to was quite insightful. Depression can be chronic, debilitating and painful, but it definitely is not terminal. Terminal implies that there is a highly predictable progression of the disease that inevitably results in death. I think the parent was trying to say we can easily see why terminal patients consider suicide, as they have a fairly determined remaining life, but we should also extend that same sympathy and understanding to those who have conditions which are chronic and painful, but not necessarily determinative of remaining lifespan.
It seems much more likely to just be invention of fire and control of fire. Turning cellulose into energy that promotes some sort of evolutionary advantage is pretty limited in the macroscopic biological world. Sure, cows and the like do it, but only by enlisting the aid of bacteria and having four stomachs, etc. This excess energy and exclusive ecological niche then allow for more complex social systems, feeding into some sort of positive loop selecting for intelligence.
That's all conjecture from me, but it seems to make sense from basic principles.
That is true at the entire-species level assuming a uniform selection pressure against the entire species. However, evolution also occurs when a species adapts specific traits to fill an environment niche. Traits can still be selected for when the trait involved allows the organism to compete for a different set of resources. Humans also do not reproduce randomly. Currently, it is widely accepted in the Western world that people get to choose who they have children with, and that choice can select for similar traits. Marriage customs in other cultures are different, but still can have an effect on trait selection. For example, the royal families of Europe positively selected for some fairly harmful traits (like hemophilia), because other traits (already belonging to the family) were also being positively selected for filling the niche of royalty.
Consider something like a "Highlander" allele, that has a chance to randomly appear in the general population, granting them the same stipulations as in the movie. Given that there can be only one, this particular allele has terrible reproductive success in the sense that practically no offspring will ever survive. However, the gene will always tend to exist in the population. Now, if there is some event that occurs that increases the maximum of number of Highlanders, this event will put positive selection pressure on the allele, even though the general population can reproduce much faster.
My best guess would be that they are so because they are eusocial.
As I posted in a comment below somewhere, I think it is the complexity of the nervous system that drives a tradeoff with repairable bodies. A brain does not want to have to retrain itself, but the history it stores makes it entropically very energy intensive to maintain. I think this drives most of what we see here: things without complex nervous systems (pyramidal neurons and such) have no disincentive in persisting indefinitely, because their relatively simple nervous system does not take increasing amounts of energy to maintain, and thus they can budget their energy for growing and other evolutionary benefits.
Most mammals have to budget their energy such that they can maintain the state of their brain, and thus have a disincentive for eternal aging: we either need to start forgetting earlier memories, which could potentially be bad, or we have to start paying the energy price of maintaining a very complex system. Energy usage tends to get optimized by evolution, so then, we end up trading off longevity.
Mole rats, however, being eusocial, have a different evolutionary strategy than most mammals. Since the entire colony effectively behaves as a single metaorganism, losing its experienced members is particularly painful if they have valuable institutional memory. Thus, there is stronger evolutionary pressure to pay the cost of maintaining these systems.
(I realize that isn't really what you were commenting about, but it does give a thermodynamic reason for their longevity, but not one simply based on temperature.)
> Thus, there is stronger evolutionary pressure to pay the cost of maintaining these systems.
... which implies that it is biologically possible to maintain them, which implies in turn that aging is a biological trade-off and not a physical inevitability.
Yes, I agree. I guess the question is what is meant by inevitable. The meanings of biological and physical in this instance aren't really all that different, if the biological problem is a limitation of the underlying physics. Ultimately, the scarcity of usable energy is driving this trade-off, which is a physical limitation of the universe. It becomes 'possible' in the sense that a O(n^100) algorithm is 'feasible' (see Arora and Barak, section 1.6.2). If maintaining a youthful state indefinitely increases our energy consumption hundredfold entirely due to the cost of maintaining a low entropy state in a highly complex system, is that really 'possible'? If we have to pay an ever increasing energetic cost to maintain ourselves, it is both a biological trade-off and a physical inevitability.
This raises an interesting point. Having said that losing experienced members is particularly painful, I am now thinking about how someone's feeling of meaning in life affects lifespan. Could it perhaps be the case that there is a self regulation mechanism in which perceived usefulness drives the brain/body to try and stay operational longer?
Molecules don't age, but any collection of molecules with distinguishable states will eventually relax spontaneously to a higher entropy configuration. Keeping a system a certain way requires an input of energy, and eating can satisfy this up to a point, but I think the complexity of the central nervous system in certain animals eventually makes this impossible.
It isn't hard to keep any particular process 'alive'. Stars burn for a long time. The hard part comes with maintaining a process that also requires memory of the past. What would seem to be the difference between a star and biological life is that life maintains a record of some information of its past states in its DNA. However, even on top of this, many animals, especially birds and mammals, have to teach their young and train an incredibly complexly connected brain.
So I think what you end up with is an optimization that trades off between these two complexity drives: a mind and a body. An organism that has invested a lot of time into training its nervous system does not want to completely regenerate it and lose all of that information. However, from a bodily perspective, being able to regenerate would be quite useful. However, making processes more reversible comes at a price (notably, thermodynamically, it would take infinite time. computationally, reversibility requires n^2 steps for some irreversible computation done in n steps), one that is no longer worth the tradeoff if the mind cannot be usefully regenerated.
I guess my point overall is that the brain, since it wants to store information, is inherently destined for breakdown. Regenerating it might be possible, but the interconnections might be so complex that it would be energetically infeasible to maintain this complexity. In humans, the brain already utilizes 20% of our energy budget. As the organism as a whole is being optimized through evolution to do evolutionary favorable things with its energy budget, this means that energy spent maintaining itself physically indefinitely is not worth it, as compared to something like a lobster, which ostensibly doesn't have the sorts of pyramidal neurons needed for a truly, truly complex nervous system and thus might as well live forever.
I assume that people will disagree with the idea that the brain is destined to break down, but if you were 10000 years old today, would you still consider yourself the same person that used to hang out with the pharaohs, having learned and forgotten hundreds of languages, names, families? It just gets absurd at some point, and the energy cost of it all is not worth it compared to reboot(strapp)ing everything from the ground up by having a child.
It is interesting the the mole rats are so long lived, and that they are also eusocial. Since institutional memory may be very important to the colony's survival, having long-lived individuals may be very helpful for an animal incapable of writing things down for posterity.
I would still say that this is all very firmly grounded in thermodynamics.
If all of a hydra's cells are replaced every four weeks, I would say that the hydra has a life span of about four weeks. Ship of Theseus and all that.
But even if you don't subscribe to that particular view of what constitutes a consistent identity, the issue is still fundamentally thermodynamic. It is not a task of just maintaining a particular dynamic system indefinitely, but maintaining one with memory. If the hydra is storing absolutely no information about its past states, then it isn't evolving, and it is completely at the mercy of its environment. This makes it more akin to fire or a piece of iron rusting than life: just a consumptive chemical process. This harmonizes exactly with your last paragraph, things need to store some amount of memory of past failure if they are to adapt. This storing process is exactly aging, but how it manifests in different organisms can obviously be very different. Landauer's principle, then, tells us that since information is thermodynamic, so too must be aging. However, I don't really think the author of the original article was arguing at that deep of a level. In humans, many of the processes that we consider to be the detrimental effects of aging do occur because the components that make us do have memory effects. One particular example would be the cross-linking of elastin, causing degradation of vascular system efficiency.
But aging truly is an inevitable consequence of thermodynamics, it's just that since everything is a consequence of thermodynamics, it's not a particularly illuminating argument.
> If all of a hydra's cells are replaced every four weeks, I would say that the hydra has a life span of about four weeks. Ship of Theseus and all that.
Most of our cells in our bodies are renewed in a few months or something. Yet people don't assimilate this to death.
Now, you may object that neurons don't follow this rule, so our subjective identity is not concerned by this. To this I will say that when people are concerned about ageing, they are indeed concerned about what happens to their brain (that is, neuro-degenerative diseases), but certainly not only that. The state of all the other tissues is at stake : the heart, the bones, the skin and so on. Yet all of these are renewed on a regular basis. That renewal is not perfect though, and it's that imperfection they blame on ageing.
So, the short answer is that diagnosis will be difficult, and there isn't really a test, but MRI with gadolinium contrast will show enhancement of the dura, and hopefully someone looking at it can see a leak if it is obvious. There are also cases of leaks being caused by a venous fistula, which does not image well.
For what it's worth, I had back-of-head-and-neck headaches intermittently for a while before this, most notably when riding rollercoasters (which I do miss). That is the only long term subtle 'sign' I can remember.
Hope this helps.
Edit: I should also probably add that my case is somewhat weird, caused by a bone malformation in my thoracic spine and difficult to localize with imaging. I had a T1 laminectomy to correct this. However, I'm not sure there are really 'standard' cases, except those that are iatrogenic due to LP or epidural in delivery.