Can apnea cause brain damage?

[trux]

Titan, it is not necessary to go into offensive if you do not like the results. The brain damage self was not (yet) proven, but the indicators (the S100B protein) are similar as for example at that kind of injury you mention - someone shoots you in head. Although we will certainly not give up our sport and hobby, it still does not mean we do not want to know what risks it involves, and whether we can push to the limits and over them in training regularly without big concern, or whether we should better take a small reserve, and attack the last risky margin just at exceptional occasions.

As for nutrients, that's not what neurologists research, so I am afraid you will need to ask someone else than Dr. Andersson.

EDIT: and I believe also AIDA and other freediving federations will be very much interested by the results. There are voices calling for changes in the surface protocol. Everyone wants to have it simpler, and less subjective, but the proposed ways to achieve it differ. Some people ask for allowing any signs of BO and LMC, and even skipping the necessity to perform any SP as long as the person is able to hold above surface (or on a support). Others propose making the protocol stricter, so that competitors may get disqualified easier. Some federations ban freedivers for several months after a BO (and even after LMC).

So knowing exactly the consequences of a BO is extremely important, and may influence also the rules.

 

[Johan Andersson]

Kars,

your questions are not all easy to answer, but I will try.

1) The biological half-time of S100B is less than 30 min.

2-4) I cannot give short answers about the functions of S100B and its role in brain damage, in particular when it comes to apnea. Partly because it is not all known. For the physiology of S100B you have to go to special references (see for instance Intracellular and extracellular roles of S100 prot... [Microsc Res Tech. 2003] - PubMed result).

We used S100B as a marker of potential brain damage, just as it is used in other conditions. It has been shown (in many circumstances) that an increase in S100B in serum is associated with a risk for brain damage. It may be that S100B is actually beneficial for the brain (i.e. involved in some type of protective function when there is something "threatening" the brain, for instance hypoxia), but still a significant increase in S100B in serum usually means that the brain is not doing OK. Remember that we cannot say that a long apnea or a blackout leads to brain damage - we can only say that it increases S100B in serum (not the same thing).

5) Maybe. I can neither confirm, nor dismiss.

6) No. We are not even sure that there really is a brain damage. The results do not say that there is brain damage. This needs to be investigated further.

/Johan

 

[Johan Andersson]

Is it certain that SB100 does not have a secondary source of production outside of the brain, activated only during metabolic (respirative) stress?

Well, I believe we can be reasonably certain that the S100B in serum that we measure comes from the brain. The tissue that comes second in place (after the brain) is adipose tissue, with approximately 3% of the relative S100B protein concentration of the brain. There is nothing in the scientific literature indicating that some tissue outside of the brain should produce S100B in response to metabolic stress.

/Johan

 

[titan]

Thanks Johan andersson, trux thank you for the elghment on the matter
but still would be interesting to ear if someone had trouble and wich kind of trouble

recently I put a post about migranes and apnea and think yes in a certain degree apnea can cause them

 

[wet]

Thanks Johan. Thought it might be potentially significant, cf serotonin.

In my thread, Mammals of the Sea, I asked if anyone reacted to sunlight (after dark adaptation) with sneeze, cry, yawn etc. I later read that sunlight can make migraines worsen, I guess the brightness might oversensitize the neural circuits of the visual part of the brain. That isn't apnea-caused, but could affect someone diving on a sunny day, with lots of glare around (waves, sand). Beachgoers may wear sunglasses but divers have to switch to goggles/mask. While diving into the dark depths, the eyes allow maximal light, then at surface they must minimize the brightness, the resulting change might stimulate (in addition to the pressure change and temperature change) some nerves.

DDeden

 

[mystiach]

Wow, great thread, very interesting reading. I'm brand new to the sport, keen to take it seriously to a competitive level, and wanted to do some reading before committing myself to something that could cause health problems. I am rather fond of my brain! A few things strike me here, bear with me, and I hope it isn't too off topic:

1) It came up earlier in the thread that the marker SB100 has been found in other sports. I would be really interested to see results for that - perhaps stressing the body and brain in other ways (eg dehydration? nobody seems to have mentioned that) can result in SB100 being released. I have zero physiology qualification so I'm sorry if that is outrageous - but I'm curious. It might go hand in hand with most sports that are really hard on the body.

2) Someone started a thread on positive effects of apnea, doesn't seem to be a lot of research in that respect. Of course we want to know what the negatives are, but I think it is just as important to find the positives. Because we might find that even though there are some negatives, they don't affect the majority of people (particularly recreational), and for competitive apnea, as suggested, if regulations are in place to enforce safe practice to the extent that these negatives are basically negligible (if people are idiots when training, that is their own problem), then at the end of the day the positives may far outweigh them.

In terms of publicity, well: swimmers get shoulder problems (and often gum problems), runners can get all kinds of joint problems, cycling has been linked to testicular cancer... the list goes on and on. Don't even start me on boxing! So it's great that someone is looking into what the possible negative effects are, because we absolutely need to know. But apnea is probably going to be under the spotlight as it becomes more and more popular, and I think it's important to bear in mind pretty well every single elite athlete for ANY sport taxes their body in some way. Negative press is bad, and annoying, particularly from ignorant and prejudiced journos, but at the end of the day, I don't think it will stop anyone from starting up the sport, and in time people *should* have enough information to learn about what the risk/benefit balance ultimately is. Which is of course what we all want to know!

Please keep the studies and articles coming!

 

[mystiach]

I might just add all this does is make me more interested in the past-time and the obviously intelligent people who partake of it

 

[Fondueset]

I am it ther no it, I! Woo woo.

 

[Johan Andersson]

1) It came up earlier in the thread that the marker SB100 has been found in other sports. I would be really interested to see results for that - perhaps stressing the body and brain in other ways (eg dehydration? nobody seems to have mentioned that) can result in SB100 being released. I have zero physiology qualification so I'm sorry if that is outrageous - but I'm curious. It might go hand in hand with most sports that are really hard on the body.

There are a few studies about this. Some examples of S100B in other sports as well as at high altitude:
Boxing and running lead to a rise in serum levels ... [Int J Sports Med. 2000] - PubMed result
Serum concentrations of two biochemical markers of... [Br J Sports Med. 2006] - PubMed result
S100B profiles and cognitive function at high alti... [High Alt Med Biol. 2010] - PubMed result

I do not know of any studies about S100B and dehydration.

/Johan

 

[mystiach]

There are a few studies about this. Some examples of S100B in other sports as well as at high altitude:
Boxing and running lead to a rise in serum levels ... [Int J Sports Med. 2000] - PubMed result
Serum concentrations of two biochemical markers of... [Br J Sports Med. 2006] - PubMed result
S100B profiles and cognitive function at high alti... [High Alt Med Biol. 2010] - PubMed result

I do not know of any studies about S100B and dehydration.

/Johan

Thankyou, Johan. Just noticed I was writing SB100... no wonder I wasn't finding any info in my searches!

 

[ploum]

Could it be simply that S100B is linked with hypercapnia ?

I mean, from a non biologist pov, you immediatly see that boxing, football, running, cycling, swimming and freediving have one thing in common : high hypercapnia level due to a body consuming more oxygen (and thus producing CO2) than the one received by breathing (be it because you consume *a lot* or because you breath less). Oh, strangely, they all seem to produce the same amount of S100B !


As hypercapnia also induces migraines and pain in the head, it made sense to me.


Personally, I don't see freediving as a special sport in that regard. When you do a 100m sprint, you are in apnea. When you are running or cycling, you need more oxygen than your lungs can come with. You are, de facto, doing apnea in any sport. (well, any physical sport, that's it)

 

[JWP]

Johann, I'm wondering if more consideration should be given to the idea that Stroke related concentration increases and exercise related exercise concentration increase are caused by different things. The reason for this is that the serum level increase from a stroke appears to result from direct damage to BBB structure (due to blood release etc). That would clearly explain the rise in the related protein.

However, running and Apnea (http://forums.deeperblue.com/freediving-science/85581-study-contractions-help-oxygenating-brain.html) both have demonstrable effects on blood circulation, especially with low oxygen levels and high CO2 blood levels. This change in circulation could potentially also trigger changes in cerebral blood pressure, compromising (the fragile) BBB. Essentially, whilst strokes provide clear BBB damage, that is not WHY they cause brain cell loss.

A possible experiment to test this would be increased blood brain pressure (weightlifting does this, or lying down at an angle to direct blood to the head?) for a period of time. It simply seems that we are in an odd position whereby running is associated with brain damage to the same extent that apnea is, and this is a rather odd situation that I think needs resolving before any more serious conclusions can be drawn.

Obviously testing the other brain damage indicators would be an ideal test. Also, how do Levels compare between running and apnea?


(I'm a neurosciences student by the way, not a complete layman!)

 

[project1.00]

apmiea dOse noot cauze brian damige

 

[Johan Andersson]

JWP, a late reply, but I didn't see your post until now.

Sadly, I have no real good replies to your first couple of comments. I just agree that there need to be more studies in the area before we can confirm or dismiss the risks for brain damage from apnea.

As for comparing running and apnea:
I think I have mentioned this before in the thread, but it may be worth repeating. It is difficult to directly compare different studies concerning S100B because you can use different analysis methods that present differing concentrations. You have to compare your own values to cutoff limits determined by your specific method. Nevertheless, the relative increase in S100B that we observed was comparable to those increases observed in boxing, headings in soccer, etc. Running/jogging caused smaller increases.

It should also be noted that the increase in S100B in our study is well below those reported after, for example, ischemic stroke and hypoxic brain damage after cardiac arrest.

 

[project1.00]

The only damage to be concerned with would be Ischemic injuries to the brain and the heart. Really though, you’re vital organs can go along time with out o2; it’s the build up of other waste products that become a problem.

Your body compensates for these things with safe guards like shock and syncope. I think the only real concern would be a hypoxic syncopal episode (black out) under water which lead to aspiration. Blacking out in the water is ok IF… you don’t aspirate. Aspiration is very bad. It’s so important to never train alone, or with out someone who is well trained to responded to a black out situation. When I train I always have at least one paramedic trained in technical water rescue/water confidence on scene.

If you could hold your breath for a long enough to cause any real damage (it wouldn’t be much) you would be with the very best in the world, if not the best. :blackeye




Edit: (I'm a janitor by the way, complete layman! But, I hold my breath alot at work ... takes 4-5 min to clean a commode and on one breath ... its a work out)

 

[Rik]

A different approach could be to combine S100B with another parameter that actually measures the intensity of the dive. Have there been any experiments with lactic acid? Could an increase with S100B be linked with the decrease in oxygen in the blood?

 

[Johan Andersson]

Rik, in our original study we had too few subjects to address such correlations. But somewhat in the same line of reasoning, I posted before in this thread about a case (http://forums.deeperblue.com/freediving-science/83773-can-apnea-cause-brain-damage-5.html#post797996, DNF blackout) that resulted in high S100B directly after the blackout as well as the day after. The increase in S100B in this individual was larger than the increases in the subjects of the original study that did not blackout.

 

[Lil Dragonfly]

Freediving does cause brain damage.

Freediving leads to pool training
Pool training leads to inhaling chlorine fumes
Inhaling chlorine fumes leads to...neurotoxicity.

Stay out of traditional swimming pools at all costs. Trust me, being neurologically disabled is no walk in the park.

 

[ReefTroll]

Oh I dunno, if your theory was actually correct, I think it would make for a wonderful life.... :head

 

[MattB]

I don't know if this has been said before but the 3 minute rule that's thrown around is that brain damage occurs 3 minutes after your heart stops. I don't think that should be a problem for most people and if you are going into cardiac arrest, stop diving!