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

[MykaDives]

So there is really nothing I can do?

 

[doctormike]

So there is really nothing I can do?

Maybe get a medical evaluation to make sure that nothing else is going on... Any ear symptoms? Ear pain, hearing loss, balance issue?

Sorry, not sure what to tell you, but preventing hypercapnea is a good goal in any type of diving. Check out this article by John Chatterton.

 

[Duke Dive Medicine]

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?

Based on your description that the symptoms begin at pressure on both single dives and repetitive dives, I think that decompression illness can probably be ruled out. What's your air consumption like? My first thought is a combination of narcosis and mild hypercapnia, but tunnel vision can be a symptom of hyperventilation as well.

Best regards,
DDM

 

[doctormike]

Based on your description that the symptoms begin at pressure on both single dives and repetitive dives, I think that decompression illness can probably be ruled out. What's your air consumption like? My first thought is a combination of narcosis and mild hypercapnia, but tunnel vision can be a symptom of hyperventilation as well.

Best regards,
DDM

Sometimes hyperventilation causes hypercapnea because of increased dead space ventilation as a percentage of tidal volume. It's a confusing symptom complex and I don't understand why narcosis (80 feet?) or hypercapnia symptoms would persist for hours after the dive.

If it really presents immediately on reaching depth on the first dive of a trip, then I agree that decompression stress is probably not what is causing THAT, but it might be what is causing his symptoms to worsen with repetitive dives or days of diving. Or, whatever is going on on the first dive is a different process than what is causing symptoms after the dive.

In any case, as always, I defer to you in the field of hyperbaric medicine!

 

[MykaDives]

Maybe get a medical evaluation to make sure that nothing else is going on... Any ear symptoms? Ear pain, hearing loss, balance issue?

Sorry, not sure what to tell you, but preventing hypercapnea is a good goal in any type of diving. Check out this article by John Chatterton.

Well, I didn't want to mention it, because I figured you guys would be off the rails pronto, but I do have chronic vertigo (all day, everyday, for about 10 years). The reason I don't think the vertigo is related is because it is not an inner ear issue, but a visual sensitivity.

I was also diagnosed with asthma when I was about 12. I'm not sure that was ever an accurate diagnosis because there was no test performed - was simply, "You cough when you run in cold air, and your mom has asthma? You have asthma too, here's your inhaler." Speaking with my mom, she's actually not sure if her own asthma diagnosis is corret either. There has never been a time when I thought I HAD to use the Salbutamol inhaler, and currently they are all expired by several years. They help relieve chest congestion more than anything. On my list of things to do is to actually get asthma testing. What I find "most irritating asthma-like symptoms" is exercise in cold weather (like running below freezing temps), and MAYBE breathing cold air from a cylinder is causing some irritation and mild asthma is causing hypercapnea? I was kind of waiting to see what people would come up with before I presented this information.

I think that since it happens at pressure on both single dives and repetitive dives, decompression illness


Based on your description that the symptoms begin at pressure on both single dives and repetitive dives, I think that decompression illness can probably be ruled out. What's your air consumption like? My first thought is a combination of narcosis and mild hypercapnia, but tunnel vision can be a symptom of hyperventilation as well.

Best regards,
DDM

Thanks for your reply DDM, air consumption is pretty good. I am female, 5'7", 130lbs. If I concentrate on air consumption I can usually "under breathe" the small male instructors with thousands of dives. If I'm not specifically thinking about air consumption, then I will use a bit more.

 

[Ghost95]

Any chance you're using a full face mask? The only time I've ever had weird issues I was using an old style mask without the oral/nasal cup. I feel I built up Co2 in the mask. I was very relaxed and crawling around the bottom with just little breaths through my nose. I got kind of buzzy, foggy, sparkles in my vision, not fun.

Other ideas, cardiac workup good? Suit too tight around your neck?

Wait, What? Asthma? Visual Vertigo?

I'd get a medical clearance before doing anything else.

 

[chillyinCanada]

How's your back and neck?

 

[MykaDives]

Any chance you're using a full face mask? The only time I've ever had weird issues I was using an old style mask without the oral/nasal cup. I feel I built up Co2 in the mask. I was very relaxed and crawling around the bottom with just little breaths through my nose. I got kind of buzzy, foggy, sparkles in my vision, not fun.

Other ideas, cardiac workup good? Suit too tight around your neck?

Wait, What? Asthma? Visual Vertigo?

I'd get a medical clearance before doing anything else.

No full face mask. Cardiac is fine as far as I know, I'm 37, female, good weight, healthy lifestyle. I've had medical clearance for diving all along since I needed clearance for asthma to do the ciurss, and redo every 2 years.

I hold a class 1 license (semi trucks), and they haven't taken that away because of vertigo.

How's your back and neck?

No known issues.

 

[chillyinCanada]

No full face mask. Cardiac is fine as far as I know, I'm 37, female, good weight, healthy lifestyle. I've had medical clearance for diving all along since I needed clearance for asthma to do the ciurss, and redo every 2 years.

I hold a class 1 license (semi trucks), and they haven't taken that away because of vertigo.



No known issues.

Seem like something it getting pinched or compressed. The pin point vision, did you also feel like you might pass out?

 

[Ghost95]

Myka, just wanted to be the first off the rails and get it out of the way.

I asked about cardiac work up because at 41 I had a heart stent for a 100% blockage. Symptom free until 3 months or so before stress test. No heart damage and stents now have good flow. Cleared for diving by Doc after stress/treadmill tests.

The only thing I can think of causing tunnel vision is reduced circulation or high Co2 but there may be many other explanations I've never heard of.

I'd still get another medical focused on diving. The tunnel vision would bug me nonstop.

I hope you get it figured out. Be safe.