DCS or Pinched Nerve?

[Diveholic]

I’m a newish diver, 70ish dives since April 2023. I’ve had 3 occasion after several days of diving (4-5 days, 3-4 dives per day, always diving within the limits of my Suunto D5 which I hear is very conservative), towards the end of my trip I’ll have a prickly sensation on the back of my thighs that persists for a few days (3-5 days). The skin in the area looks normal when I have these symptoms. I had a TTE and TEE to rule out a PFO, the findings are as follows:

“No obvious PFO. Weakly positive bubble study with 1-2 bubbles maximum seen only on two valsalva bubble studies out of a total of 6. Negative bubble studies on TTE. On the last bubble study with RUPV in view, a few tiny bubbles are seen arriving into the LA from the RUPV consistent with a tiny transpulmonary shunt.”

Would the tiny transpulmonary shunt be enough to suspect DCS, given that I am diving within the limits of my computer? My doctor seems quick to dismiss it as DCS but I’m wondering if a pinched nerve would be more likely as I am often hauling heavy gear and have some mild back pain due to this.

To note, I also notice some mild dizziness (like my head is spinning) after diving and after boat rides. This does not always occur after each dive/boat ride but is often present at least sometimes during my diving trips. I don’t usually have a problem equalizing but have recently developed mild left ear pain (1/10 but present on and off for several days).

Would love to get some perspective from people who may have had a similar experience (mostly regarding the tingling) or any medical professionals out there. I understand that advice online does not substitute proper medical examination, but I live in Canada where referrals to an ENT or neurologist are not easy to get. Any suggestions would be greatly appreciated!

 

[-JD-]

I won't comment on DCS as I am not a doctor and do not have any personal experience.

On the other hand, I have had lumbar disc issues resulting in nerve impingement, and would encourage you to talk to your doctor about the possibility. Knowing and preventing further progression is WAY better than dealing with the aftermath.

 

[Duke Dive Medicine]

I’m a newish diver, 70ish dives since April 2023. I’ve had 3 occasion after several days of diving (4-5 days, 3-4 dives per day, always diving within the limits of my Suunto D5 which I hear is very conservative), towards the end of my trip I’ll have a prickly sensation on the back of my thighs that persists for a few days (3-5 days). The skin in the area looks normal when I have these symptoms. I had a TTE and TEE to rule out a PFO, the findings are as follows:

“No obvious PFO. Weakly positive bubble study with 1-2 bubbles maximum seen only on two valsalva bubble studies out of a total of 6. Negative bubble studies on TTE. On the last bubble study with RUPV in view, a few tiny bubbles are seen arriving into the LA from the RUPV consistent with a tiny transpulmonary shunt.”

Would the tiny transpulmonary shunt be enough to suspect DCS, given that I am diving within the limits of my computer? My doctor seems quick to dismiss it as DCS but I’m wondering if a pinched nerve would be more likely as I am often hauling heavy gear and have some mild back pain due to this.

To note, I also notice some mild dizziness (like my head is spinning) after diving and after boat rides. This does not always occur after each dive/boat ride but is often present at least sometimes during my diving trips. I don’t usually have a problem equalizing but have recently developed mild left ear pain (1/10 but present on and off for several days).

Would love to get some perspective from people who may have had a similar experience (mostly regarding the tingling) or any medical professionals out there. I understand that advice online does not substitute proper medical examination, but I live in Canada where referrals to an ENT or neurologist are not easy to get. Any suggestions would be greatly appreciated!

Given your description I don't think that DCS can be completely ruled out, though your symptoms could also be explained by nerve impingement as you mentioned (possibly sciatic given the location of the tingling) and some combination of alternobaric vertigo and seasickness.

As difficult as it is to get a neurologist and ENT evaluation, it sounds like you could benefit from both. Where in Canada are you? If you're close to Vancouver, Ottawa, or Toronto, there are diving medical examiners who could evaluate you and possibly refer you to those specialists.

Best regards,
DDM

 

[Diveholic]

Thank you both for your comments.

Given your description I don't think that DCS can be completely ruled out, though your symptoms could also be explained by nerve impingement as you mentioned (possibly sciatic given the location of the tingling) and some combination of alternobaric vertigo and seasickness.

As difficult as it is to get a neurologist and ENT evaluation, it sounds like you could benefit from both. Where in Canada are you? If you're close to Vancouver, Ottawa, or Toronto, there are diving medical examiners who could evaluate you and possibly refer you to those specialists.

Best regards,
DDM

I’m located in Toronto. I actually did see a hyperbaric specialist who was the one who dismissed it as DCS. I thought I would get a second opinion given the uncertainty of the lab results (weakly positive, potential tiny pulmonary shunt) and the potential for an alternative diagnosis as the specialist was not interested in referring me to a neurologist, and because I don’t currently have a family doctor (recent-ish move to Toronto and it’s very difficult as a young person with no complex med history to find a GP here). I was hoping there would be a way to distinguish between nerve impingement and DCS without the referral to a neurologist but it’s seeming unlikely.

I guess until I am able to be reevaluated, I will have to dive conservatively…

Just to clarify, the mild dizziness is never present in the water, and usually is an issue when I am sitting still and looking at a still object (e.g. looking at a computer screen); I have never experienced it when I am walking or driving. I thought it may be MdDS but it also occurred after a shore dive (instead of my typical boat dives). It may occur even after just 1 day of diving and once I experience it, it will typically last a few days (1-5 days).

 

[Duke Dive Medicine]

Thank you both for your comments.

I’m located in Toronto. I actually did see a hyperbaric specialist who was the one who dismissed it as DCS. I thought I would get a second opinion given the uncertainty of the lab results (weakly positive, potential tiny pulmonary shunt) and the potential for an alternative diagnosis as the specialist was not interested in referring me to a neurologist, and because I don’t currently have a family doctor (recent-ish move to Toronto and it’s very difficult as a young person with no complex med history to find a GP here). I was hoping there would be a way to distinguish between nerve impingement and DCS without the referral to a neurologist but it’s seeming unlikely.

I guess until I am able to be reevaluated, I will have to dive conservatively…

Just to clarify, the mild dizziness is never present in the water, and usually is an issue when I am sitting still and looking at a still object (e.g. looking at a computer screen); I have never experienced it when I am walking or driving. I thought it may be MdDS but it also occurred after a shore dive (instead of my typical boat dives). It may occur even after just 1 day of diving and once I experience it, it will typically last a few days (1-5 days).

Differential diagnosis can't be done over the internet unfortunately. Glad you were evaluated by a hyperbaric physician and DCS was ruled out, but unfortunate that they couldn't, or wouldn't, refer you to specialists.

It's sometimes hard to distinguish between dizziness (what people in the American south call "swimmy-headed") and vertigo, or the perception of motion when there isn't any. Post-dive vertigo is hard to differentiate, but given your description and your evaluation by a hyperbaric physician, it's probably not related to DCS. If it happens post-dive, I would lean more toward mild alternobaric vertigo. Here's a link to an article that describes different types of barotrauma and their effects. And, just so it's asked, how vigorously are you equalizing your ears? Forceful Valsalva maneuvers can traumatize the inner ear and also lead to vertigo.

Best regards,
DDM

 

[Diveholic]

Sorry @Duke Dive Medicine , I may have miscommunicated in my previous response. The hyperbaric specialist seemed to have decided that my symptoms were DCS based on the TTE/TEE findings I posted above and was not interested in investing more time in investigating a differential diagnosis (hence the lack of referral to a neurologist). I used to equalize via Valsalva (I didn’t feel like it was forced but I’m told Valsalva can be unintentionally quite forceful) and so have changed my methods to others that don’t involve the use of my diaphragm (usually pinch and swallow). From your description, I would categorize my symptom as vertigo, as when I am still and looking at a screen, it feels like I’m still moving (kind of like I’m on a boat but much less in intensity). Given the presence of mild left ear pain, I also thought it was related to some sort of barotrauma.

I’m really feeling hopeless as I’ve been diving recreationally within my limits (although some would argue diving more than twice a day is pushing them) and now feel stuck. If it was a PFO I probably would have gotten it closed, but my hyperbaric specialist said there’s nothing you can do about an intrapulmonary shunt ☹ (that is, if DCS is the correct diagnosis)

 

[Duke Dive Medicine]

Sorry @Duke Dive Medicine , I may have miscommunicated in my previous response. The hyperbaric specialist seemed to have decided that my symptoms were DCS based on the TTE/TEE findings I posted above and was not interested in investing more time in investigating a differential diagnosis (hence the lack of referral to a neurologist). I used to equalize via Valsalva (I didn’t feel like it was forced but I’m told Valsalva can be unintentionally quite forceful) and so have changed my methods to others that don’t involve the use of my diaphragm (usually pinch and swallow). From your description, I would categorize my symptom as vertigo, as when I am still and looking at a screen, it feels like I’m still moving (kind of like I’m on a boat but much less in intensity). Given the presence of mild left ear pain, I also thought it was related to some sort of barotrauma.

I’m really feeling hopeless as I’ve been diving recreationally within my limits (although some would argue diving more than twice a day is pushing them) and now feel stuck. If it was a PFO I probably would have gotten it closed, but my hyperbaric specialist said there’s nothing you can do about an intrapulmonary shunt ☹ (that is, if DCS is the correct diagnosis)

Oh, that changes things, thanks for clarifying and my apologies for misinterpreting your post. Were you treated in the chamber for DCS? If so, did the symptoms resolve with treatment? What were your dive profiles like? 'Within the limits' is pretty broad; we've treated a lot of divers for DCS whose computers said they were inside no-stop limits.

If you weren't treated in the chamber or if the results were inconclusive, you could try doing the same type of dive series, only very shallow (10 m / 33 feet or less for good measure), and see if you can duplicate the tingling symptoms. If you can, then you would have an additional data point to take back to the specialist. I would stay out of the water until the ear is good and healed though, 4-6 weeks minimum, and it equalizes easily on the surface.

Best regards,
DDM

 

[Diveholic]

Unfortunately I wasn’t treated in the chamber nor received emergency O2 when I had the symptoms and therefore can’t say. Typically my dives are either one or no ‘deep’ (> 20m) shorter (<30 min) dives, followed by shallower dives. Great advice on the experiment to replicate the dives in a shallow environment - I’ll definitely give it a try when I get the chance. Would you recommend that I get treated in a chamber if I experience the same tingling sensation?

Thanks for the advice regarding the ears. I’ll make sure to wait until they heal before re-entering the water

 

[Duke Dive Medicine]

Unfortunately I wasn’t treated in the chamber nor received emergency O2 when I had the symptoms and therefore can’t say. Typically my dives are either one or no ‘deep’ (> 20m) shorter (<30 min) dives, followed by shallower dives. Great advice on the experiment to replicate the dives in a shallow environment - I’ll definitely give it a try when I get the chance. Would you recommend that I get treated in a chamber if I experience the same tingling sensation?

Thanks for the advice regarding the ears. I’ll make sure to wait until they heal before re-entering the water

Interesting - were you symptomatic at the time you were evaluated?

If it happens again on very shallow dives I would recommend that you be evaluated by the same diving physician/group who evaluated you earlier. That would give them additional data with which they might modify their recommendations.

Best regards,
DDM

 

[Diveholic]

No, my appointments with the hyperbaric specialist were well after the symptoms had subsided. When I initially contacted DAN after the symptoms occurred for the second time (I thought the first time it happened was due to the hot weather/sweating?), they didn’t think it was related to DCS or that I needed to get recompressed, but recommended that I go see a diving medicine specialist, which I did.

Literally as I am typing this I noticed the onset of tingling in my legs again; my last dive was over the weekend when I was doing my rescue course (very short and shallow dives, followed by one 25 min dive at max 8m) and my hyperbaric specialist will see me tomorrow first thing in the morning…sigh