Brain fog during and after deep(ish) /multiple dives

[MykaDives]

I've discussed this with several people and haven't really had much clarity provided. Maybe you folks have some ideas.

I dive mainly in cold freshwater lakes that vary 38-45F mainly, and the issue becomes apparent when I dive around 80 feet or more, and/or do multiple dives (DM with OW/AOW students over a weekend). The issue is both underwater and on surface. I will feel like my brain is foggy, like I'm just going through the motions, almost like I get really, really tired and want to fall asleep (like when you're watching a movie and kinda falling asleep). I'm not falling asleep, but it's kind of the same feeling, like fogginess/numbness. However, I am still able to perform well. I notice what the students are doing, I can tend to any issues, I can lead a dive with no hitch, I can tie off lines, I can do valve drills, etc. I feel foggy, but I don't perform foggy. The instructors can't tell that anything is "wrong". There was one time when I was tying a line at 87' and I got tunnel vision really suddenly, and really bad (all I could see was the line and my fingers), but as soon as I picked my head up and looked around it went away. Now this all sounds like narcosis, right? Except, I don't feel any clearer when I ascend. This feeling will stick with me on the surface for a few hours after the dive (or after the last dive of the day, whichever is later). I also get this feeling on tropical dive trips (multiple dives, multiple days).

The people I have asked about this generally say something along the lines of, "Ya I kind of feel like that too." Maybe it's normal, and I'm simply hyper-sensitive to the feeling?

Any ideas?

 

[Marie13]

Foggy, mushy brain? I get that beginning about 115ft on the Great Lakes. Don’t know about the wanting to go to sleep, but the brain mush is part of being narced.

 

[MykaDives]

Yeah, I've assumed it is narcosis for a few years, but I'm starting to question why it doesn't go away for a few hours? People always say they ascend some ways and they clear right up. That doesn't happen for me.

 

[Pearlman]

Quick - Q : Do you experience this only when diving? If not I have a solution that works for me and should hopefully work for you as well.

PS: Maybe you want to move this to the diving medicine forum ... ?

 

[Graeme Fraser]

I've discussed this with several people and haven't really had much clarity provided. Maybe you folks have some ideas.

I dive mainly in cold freshwater lakes that vary 38-45F mainly, and the issue becomes apparent when I dive around 80 feet or more, and/or do multiple dives (DM with OW/AOW students over a weekend). The issue is both underwater and on surface. I will feel like my brain is foggy, like I'm just going through the motions, almost like I get really, really tired and want to fall asleep (like when you're watching a movie and kinda falling asleep). I'm not falling asleep, but it's kind of the same feeling, like fogginess/numbness. However, I am still able to perform well. I notice what the students are doing, I can tend to any issues, I can lead a dive with no hitch, I can tie off lines, I can do valve drills, etc. I feel foggy, but I don't perform foggy. The instructors can't tell that anything is "wrong". There was one time when I was tying a line at 87' and I got tunnel vision really suddenly, and really bad (all I could see was the line and my fingers), but as soon as I picked my head up and looked around it went away. Now this all sounds like narcosis, right? Except, I don't feel any clearer when I ascend. This feeling will stick with me on the surface for a few hours after the dive (or after the last dive of the day, whichever is later). I also get this feeling on tropical dive trips (multiple dives, multiple days).

The people I have asked about this generally say something along the lines of, "Ya I kind of feel like that too." Maybe it's normal, and I'm simply hyper-sensitive to the feeling?

Any ideas?

Definitely sounds like narcosis, apart from not clearing on ascent. Possible hypercapnia (CO2 retention) which can take a while to clear? Might be worth posting in dive medicine. In the meantime, are you trimix qualified? If so, try the same dive with a helium mix and see if that makes a difference.

 

[JMBL]

I'd second narcosis + hypercapnia. Had the problem some years ago, diving in 12°C water, below 40m. Felt I was more narked than usual and got a headache... Turned out my reg was badly tuned.

 

[ofg-1]

You are sticking your head in, what for me, is insanely cold water. Here's an experiment, go and sit in a refrigerator for 30-40 minutes with a wet towel on your head. See how it feels. From the Mayo Clinic:

The signs and symptoms of the three different stages of hypothermia are:

• First stage: shivering, reduced circulation;
• Second stage: slow, weak pulse, slowed breathing, lack of co-ordination, irritability, confusion and sleepy behaviour;
• Advanced stage: slow, weak or absent respiration and pulse.

 

[MykaDives]

I didn't notice there is a Dive Medicine forum, i think a mod would have to move my thread?

I will look into diagnosing hypercapnia. I dive with several people in medicine so o could easily get blood drawn after a dive. I'm not sure how quickly after a dive that would need.to happen, or if the CO2 would have already dissipated by the time I surface? I'm also not sure if blood could sit in a vial for several hours before getting tested (which would be the situation).

Quick - Q : Do you experience this only when diving? If not I have a solution that works for me and should hopefully work for you as well.

PS: Maybe you want to move this to the diving medicine forum ... ?

Only when diving. I looked for a Medicine forum, but didnt notice one. If a modncould move it, that.would be great! Thanks!

Definitely sounds like narcosis, apart from not clearing on ascent. Possible hypercapnia (CO2 retention) which can take a while to clear? Might be worth posting in dive medicine. In the meantime, are you trimix qualified? If so, try the same dive with a helium mix and see if that makes a difference.

I am taking Tech 1 in February, and am curious if there may be a difference - that would confirm narcosis.

I'd second narcosis + hypercapnia. Had the problem some years ago, diving in 12°C water, below 40m. Felt I was more narked than usual and got a headache... Turned out my reg was badly tuned.

I'll look into figuring out how to diagnose hypercapnia, seems to be the consensus here.

You are sticking your head in, what for me, is insanely cold water. Here's an experiment, go and sit in a refrigerator for 30-40 minutes with a wet towel on your head. See how it feels.

You missed the part where I said this happens on tropical dive drips as well. I'm rarely cold on a dive, I have excellent underwear and a heater too if I need it (which I've never actually used during a dive haha).

 

[ofg-1]

IYou missed the part where I said this happens on tropical dive drips as well. I'm rarely cold on a dive, I have excellent underwear and a heater too if I need it (which I've never actually used during a dive haha).

You are correct, As a native Floridan, I was so discombobulated when I saw that someone would, by choice and for fun, get into 38 degree water, I missed the rest.

 

[doctormike]

80 feet and persists after surfacing? Doesn't sound anything like narcosis. Same for hypercapnea, doesn't sound like typical symptoms or consistent with the persistence.

Far more likely to be decompression stress, assuming no other underlying medical condition. We think of getting bent as a binary thing - you either need a chamber ride or you are fine. But everyone bubbles on ascent, and if you do a number of dives in a short time, for multiple days, the effect is additive. Fatigue, flu-like symptoms, foggy thinking, etc... all are seen with decompression stress.