DCS in optic nerve. PFO?

[PeterNBiddle]

have not had (and do not intend to have) a scan.

Why in the world not?

 

[doctormike]

Not an expert at all, but all I could find on pubmed for optic nerve injuries with diving were reports of barotrauma (the optic nerve runs in the wall of the sphenoid sinus, so sinus barotrauma could cause direct pressure injury to the nerve.

While this may be a diving injury (i.e. barotrauma), unless you spent a LONG time at 10 meters you wouldn't have that much nitrogen loading. DDM would be the best person to answer these questions, or possibly TSandM...

Mike

 

[Duke Dive Medicine]

I noticed the central visual loss in the evening after diving so a few hours after I'd been diving. I suffer from migraines that cause a central aura so I'm quite "good" at seeing past them and don't notice them until they are really bad. The symptoms continued to worsen in the following days and I sought medical advice when I was out there. The symptoms definitely worsened when I flew home.

Several hyperbaric specialists have been consulted and they are sure that this is some sort of diving insult. There are apparently reports in the literature of optic neuritis following diving to as little as 5m! (Though I've been unable to find these reports on pubmed)

I do not have MS and the specialists I've spoken to are quite adamant of that (My vision is returning too quickly for it to be a demyelinating disorder) I have not had (and do not intend to have) a scan. I'm being guided by the specialists that are trying to help me, and PFO seems like a likely cause of AGE and a cause of optic neuritis. From where I'm sitting this is pretty darned serious injury!

So, you don't have MS... sorry, your first post led me to believe that you did.

I couldn't find anything on optic neuritis related to decompression sickness either. There are two papers on barotraumatic optic neuropathy in divers:

Transient vision loss at depth d... [Undersea Hyperb Med. 2012 Sep-Oct] - PubMed - NCBI
Unilateral optic neuropathy from... [Undersea Hyperb Med. 2013 Jan-Feb] - PubMed - NCBI

These cases are not bubble-related injuries though, and both divers' symptoms appeared during pressure changes, so it doesn't really mirror what happened to you. I don't want to second-guess people who have examined you in person, but from everything you have posted I'm still unconvinced that your vision change has anything to do with decompression sickness and would certainly not rush to that diagnosis without ruling out other causes. I would be interested to read any references that your consultants could provide regarding isolated optic neuropathy that is related to decompression sickness.

Best regards,
DDM

 

[beanojones]

Not an expert at all, but all I could find on pubmed for optic nerve injuries with diving were reports of barotrauma (the optic nerve runs in the wall of the sphenoid sinus, so sinus barotrauma could cause direct pressure injury to the nerve.

While this may be a diving injury (i.e. barotrauma), unless you spent a LONG time at 10 meters you wouldn't have that much nitrogen loading. DDM would be the best person to answer these questions, or possibly TSandM...

Mike

You are saying it could be barotrauma but it is not likely DCS? Just trying to make sure I am parsing that italicized sentence correctly.

 

[doctormike]

You are saying it could be barotrauma but it is not likely DCS? Just trying to make sure I am parsing that italicized sentence correctly.

Exactly. Sorry if I was unclear.

Diving injuries fall into a number of categories - DCI (which includes DCS and arterial gas emboli), barotrauma (e.g. sinus and ear squeeze, pulmonary expansion injury), drowning, oxygen toxicity, immersion pulmonary edema, etc...

DCI conditions are dependent on loading the tissues with inert gas (usually nitrogen) and then a decrease in ambient pressure faster than this gas can be safely eliminated from the tissues.

So while you can (and some have) suffer a serious injury by a quick shallow bounce dive with breath holding on the way up, if you are not breathing compressed gas at depth long enough to load a significant amount of nitrogen into your tissues, it wouldn't be a form of DCI.

I have actually seen pulmonary expansion injuries grouped under DCI, but it doesn't seem that this would be accurate. The real decompression experts on the forum can correct me if I am wrong, though....

 

[Duke Dive Medicine]

From the experts via the middle man:

Vann RD, Butler FK, Mitchell SJ, Moon RE (2011), Decompression Illness, The Lancet, 377, 153-164

"Decompression illness is caused by intravascular or extravascular bubbles that are formed as a result of reduction in environmental pressure (decompression). The term covers both arterial gas embolism, in which alveolar gas or venous gas emboli (via cardiac shunts or via pulmonary vessels) are introduced into the arterial circulation, and decompression sickness, which is caused by in-situ bubble formation from dissolved inert gas. Both syndromes can occur in divers, compressed air workers, aviators, and astronauts, but arterial gas embolism also arises from iatrogenic causes unrelated to decompression."

Best regards,
DDM