Labyrinthitis and Inner Ear Decompression Sickness

[Scubaguy62]

A little over 1 yr ago, I assisted my instructor in attending a diver whom we suspected was suffering from DCS. The dive was shallow (40 fsw), and I, along with the instructor, had done the dive with the OW class, who was on their last check-out dive. The diver was a young man in his early 20's and well fit for his age.

He came up complaining of diziness and nausea, and his left hand began twitching uncontrollably and closing into a fist, so we laid him down on his left side and called for the boat's O2 supply, and immediately administered O2. The boat returned immediately to the dock where the paramedics were already waiting for us. I later learned that this young man had undergone 2 days of hyperbaric treatment, and that he would not be able to ever dive again. I was not explained in detail what happened to him, nor did I know the diagnosis.

Last weekend I had a chance to dive with the operator with whom I dove that day, and learned the name of the condition this young man had; Labyrinthitis. I've since read on labyrinthitis on Scuba-doc's website, and it appears that labyrinthitis is a condition that could be linked to IEDCS, but that it usually happens on deep dives, and that there are very few cases of IEDCS from shallow dives.

I'm curious if this guy could have had a case of IEDCS on top of the labyrinthitis, hence the reason for hyperbaric treatment, or whether labyrinthitis alone would require hyperbaric treament.

Thanks in advance.

[H2Andy]

i had no clue myself, so i looked it up. a quick definition:

Labyrinthitis is an inflammation or dysfunction of the vestibular labyrinth, which is a system of intercommunicating cavities and canals in the inner ear. The syndrome is defined by the acute onset of vertigo that commonly is associated with head or body movement. Nausea, vomiting, or malaise often accompanies the vertigo.

Vertigo is the subjective sensation of environmental movement that may be experienced as a mild subjective instability of the surroundings or, in its most severe form, as a spinning sensation. Vertigo may be experienced and described anywhere between these 2 extremes. Vertigo syndromes have many synonyms, including labyrinthitis, benign positional vertigo, cupulolithiasis, and vestibular neuronitis.

from http://www.emedicine.com/emerg/topic290.htm

laberynthitis is an absolute contraindication to diving
(i.e. can't dive if you have it):

http://www.scuba-doc.com/entprobs.html

[Scubaguy62]

Andy, we're right on track. I read those two websites as well, but I can't seem to understand the need for hyperbaric treatment unless the case involved IEDCS, which according to Scuba-Doc's article is rare on shallow dives, notwithstanding that he refers to dives to 30 meters as shallow dives.

[Dr Deco]

It is my understanding that inner ear DCS is generally the result of gas switching when the divers are in a dry hyperbaric chamber. It is believed to be a counter transport problem and does respond to pressure therapy.

Dr Deco

[Saturation]

There is a possibility of labyrinthitis but the hand twitching and 2 days of hyperbaric treatment suggests CAGE must be ruled out first, including evaluating a good sized PFO or some other shunt.

Reasons I say that are the ff, give limited information:

Shallow dive, young person on his first dives. IEDCS is extremely unlikely, as Dr. Deco mention it occurs mostly in decompression level diving.

Round window rupture is more common for those depths on ascent, and leads to the same symptoms, but without the hand twitching uncontrollably ... that is a worse case a focal convulsion episode, and nausea vomiting here could also mean the brain, not the ear was hit, specifically a cerebellar injury gives the same symptoms. However, compression is NOT the treatment for round window rupture considerations but it is for CAGE.

Labyrinthitis is a form of middle ear dysfunction, it need not be treated with recompression. Once treated it is not a contraindication to diving. However, if it doesn't resolve, then diving is precluded until treated. Since there are many causes, an ENT consult may find a solution, if said diver wishes to continue to dive.

OTAH, CAGE with cerebellar injury is difficult to treat, requires multiple treatment and explains all the victims symptoms. Since the bends was seemingly an undeserved hit, it suggests bubbling past a shunt, commonly a PFO ... and such severe manifestation suggests its quite a large one. Without repair, it would preclude diving too.

OTAH, finally if nothing was found via thorough testing, labyrnthitis can be diagnosed through many other means. If its the idiopathic type, no known cause or triggers, it too precludes diving ... but as its non-lethal and recompression does nothing for it, it would be a diagnosis searched for after CAGE was ruled out as a possibility.