Vertigo....can't remember dive

[rsingler]

Your episode is very much like what happened to a student of mine two months ago. There is a fluke occurrence that can happen to colder water divers with hoods.
When you submerge, if one ear stays briefly dry, while the other gets a dollop of cold water right down the ear canal, you essentially are giving yourself what neurologists call a "cold water caloric test". This is a Neuro test that will elicit signs valuable in diagnosis, but which also instantly induces severe vertigo, due to the differential brain input from each ear, where the balance organs live.

My student had incapacitating vertigo, and could only shut his eyes to minimize symptoms. It's not just dizziness, but an intense disorientation that overwhelms most other brain input. In his case, he kept it together long enough to add a puff of air to his bcd at 10 feet, which he knew would carry him to the surface. He could not tell which way was up. He became nauseated.

In your case, I'd suggest that perhaps rather than memory loss, your senses were overloaded to the point where not much else on the dive even imprinted.

Once out of the water, symptoms largely subside, and on the next dive, your ears got their cold water exposure simultaneously. Hence, no recurrence.

Diving Doc

 

[jmark18]

First, check your air to ensure you did not suffer from carbon monoxide poisoning. This would be consistent with your feeling better after stopping breathing off the scuba.

Second, unequal equalization should have nothing to do with vertigo, unless you ruptured an ear drum (which it appears did not happen). Also, there should be no way a "bubble" could get to your inner ear to cause vertigo. However, there are two structures, the Round (Eliptical) Window and the Oval (Circular) Window, which if disturbed could possibly cause vertigo. It is the semi circular canals, which are normally liquid-filled, that affect balance in the inner ear, and would be the source of your vertigo. But they really are not affected by equilization unless something happens to one of those windows to the inner ear.

SeaRat

Unequal equalization is in fact the MOST COMMON cause of vertigo underwater- alternobaric vertigo

 

[John C. Ratliff]

Unequal equalization is in fact the MOST COMMON cause of vertigo underwater- alternobaric vertigo

ThaKs, I had not heard of unequal equilization causing vertigo.

SeaRat

 

[Duke Dive Medicine]

Your episode is very much like what happened to a student of mine two months ago. There is a fluke occurrence that can happen to colder water divers with hoods.
When you submerge, if one ear stays briefly dry, while the other gets a dollop of cold water right down the ear canal, you essentially are giving yourself what neurologists call a "cold water caloric test". This is a Neuro test that will elicit signs valuable in diagnosis, but which also instantly induces severe vertigo, due to the differential brain input from each ear, where the balance organs live.

My student had incapacitating vertigo, and could only shut his eyes to minimize symptoms. It's not just dizziness, but an intense disorientation that overwhelms most other brain input. In his case, he kept it together long enough to add a puff of air to his bcd at 10 feet, which he knew would carry him to the surface. He could not tell which way was up. He became nauseated.

In your case, I'd suggest that perhaps rather than memory loss, your senses were overloaded to the point where not much else on the dive even imprinted.

Once out of the water, symptoms largely subside, and on the next dive, your ears got their cold water exposure simultaneously. Hence, no recurrence.

Diving Doc

Good thought Bob. How long did it take your student's vertigo to resolve on the surface? I've never seen caloric vertigo in the water but I used to demonstrate it on my commercial diving students by first placing a trash can next to the lucky volunteer in case of accident, then pouring a small amount of ice water into one of his ears and asking him to describe what he felt; then, if he felt froggy enough, to try walking. It generally resolved quite rapidly once the fluid in the semicircular canals warmed up.

 

[rsingler]

I used to demonstrate it on my commercial diving students by...pouring a small amount of ice water into one of his ears

You're a brutal instructor, lol!

Yeah, my guy's vertigo cleared within a few minutes of bobbing on the surface, though his persistent nausea prompted him to call the dive and the rest of the day.

 

[rob.mwpropane]

Wow, lots of good info here.

I do agree that it might not have been full on memory loss as I saw a picture of some chains we were supposed to try and lift from one of the sea floors and I remember seeing that. My senses could have just been so overloaded that I don't remember the rest of the dive, or vaguely anyway.

Given your report of a change in your equalization, the rapid resolution of symptoms on the surface, and subsequent dives without problems, I think it's unlikely that contaminated gas caused your symptoms. Several diving-related things can happen to the ear that can cause vertigo. Inner ear barotrauma and decompression sickness are probably the most serious. The rapid resolution of your symptoms pretty much rules out both of those; and, as you pointed out, the symptoms set in on descent, which also essentially rules out DCS as a cause.

It's interesting that this should come up again as it's been the subject of a couple of other threads recently, but one possible cause of transient vertigo and nausea while diving is a phenomenon called alternobaric vertigo, where one middle ear equalizes but the other does not. Symptoms typically resolve in minutes to hours as the offending ear clears. However, this does not explain your neurological symptoms. There are reports of divers experiencing focal neurological symptoms at depth that resolve spontaneously on the surface, the result of a bony dehiscence in a sinus that leaves the central nervous system exposed to pressure changes in that sinus. This could be to blame here; it's probably a bit of a reach but I don't think it can be ruled out.

It's also possible that there's a non-diving-related cause here, with transient ischemic attack (TIA, or mini-stroke) being the most concerning. I recommend that you see a diving physician or your primary care physician ASAP and get referrals to both a neurologist and an ear/nose/throat physician. I would also strongly caution you against diving again until you get to the bottom of this. If you PM me your location I'll see if there's a facility in your area that has a physician trained in evaluating divers. It might be good to have a diving doc in the driver's seat for you.

Best regards,
DDM

Could having chronic sinus issues contribute to that? I've had sinus surgery twice. They tried to fix a deviated septum and clean out polyps. Neither surgery took all that great and I'm just living with it for now. It does cause me to have more problems equalizing than most have, at least for the first dive of the day.

Is there anything you'd recommend to prevent that?

I live in Maryland about 30 minutes north east of Baltimore, please feel free to send me whatever you might have. Any and all help is greatly appreciated.

 

[annasea]

Unequal equalization is in fact the MOST COMMON cause of vertigo underwater- alternobaric vertigo

Interesting; never heard of this. I still have less than 500 dives, but I've never had this happen to me and I always equalize unequally--assuming I'm understanding the term correctly. My right ear is very fussy and will only equalize by me putting my tongue against the roof of my mouth then swallowing, which is never in sync with the left ear as it always clears first.

 

[Duke Dive Medicine]

Wow, lots of good info here.

I do agree that it might not have been full on memory loss as I saw a picture of some chains we were supposed to try and lift from one of the sea floors and I remember seeing that. My senses could have just been so overloaded that I don't remember the rest of the dive, or vaguely anyway.



Could having chronic sinus issues contribute to that? I've had sinus surgery twice. They tried to fix a deviated septum and clean out polyps. Neither surgery took all that great and I'm just living with it for now. It does cause me to have more problems equalizing than most have, at least for the first dive of the day.

Is there anything you'd recommend to prevent that?

I live in Maryland about 30 minutes north east of Baltimore, please feel free to send me whatever you might have. Any and all help is greatly appreciated.

It's possible. An ENT physician would be able to tell you for sure and provide individualized recommendations for you. Sent you a PM about a group of diving physicians in your area.

Best regards,
DDM

 

[Duke Dive Medicine]

Interesting; never heard of this. I still have less than 500 dives, but I've never had this happen to me and I always equalize unequally--assuming I'm understanding the term correctly. My right ear is very fussy and will only equalize by me putting my tongue against the roof of my mouth then swallowing, which is never in sync with the left ear as it always clears first.

It's more common on ascent and it's comparatively rare, I've only seen it a handful of times in 35-odd years of diving/hyperbarics. It can also happen in non-diving situations. My oldest child had it with an ear infection.