Long term effects of recreational diving....scientific data?

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Harley1962

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I'm a Fish!
As a PADI Professional, I recently attended a lecture from a Chamber Operator / Technician (Chamber located within an International Hospital), and I was a bit surprised to hear this individual describe "documented scientific evidence" gleaned from data taken from frequent and long-term recreational divers. I want to emphasize that he was NOT talking about technical or commercial divers (nor about divers who have experienced DCI / DCS in the past), but simply people who dive somewhat regularly at recreational depths. He wasn't specific as to the definition of "frequent" divers, but as a PADI Instructor who make a living teaching-diving, I inferred that I would certainly fall into that group. He claimed that in this group there is peer-reviewed (documented) evidence of short-term memory loss, lessening of high-cognitive functions, more likelihood of frequent headaches (and migraines), and higher susceptibility to depression and mental illness. This sentence was taken verbatim, so I could enter it again on this forum. So, can anybody please refer me to such articles or data--he basically said that repetitive diving makes us "stupid" over a period of years, and I'm not inclined to believe that without some peer-reviewed evidence from the Baro-medical community! Maybe I'm just "in denial" here, but I want some hard FACTS! I'd appreciate any data or web links that you can provide to enlighten me--or disprove that fellow's rather frightening statement! HB
 
I've never heard anything of the sort ... but they do say that you have to be nuts to dive, so perhaps it is the other way round?
 
Indeed, neither had I (until that lecture), and that's what makes it so discouraging (and frightening!) to people like myself who earn their living in diving and are in the water several times a week. I suppose his premise is that our exposure to pressures while diving (even at recreational depths) causes some type of neural degradation...but this is just conjecture on my part. Thus, my request for HARD data that is peer-reviewed.......it would sure be nice to know, either way!
 
I agree with him.

there was a time several years in succession of repetitive dives. weekends would be around 8 dives, with some weekday dives, and even some weeks of daily diving and even months of daily diving at open water.

now it is depressing when you start to head back to the city to face traffic pollution etc.

when in the city its hard to keep your mind on city stuff so in a way memory loss.

headaches most probably due to pollution of city and city stress.

it is depressive as you long to go back to the sea and have to endure city life. it makes you sick. :D

actively doing repetitive diving would make you into dive mode so you may be alert on those repetitive dives since you are aware of the gas buildup in your system hence you need to be very mindfull of this. after all it literally is your life that depends on it. now would you think of anything else other than your repetitive dive. to the non-repetitive diver that is stupid.

IMHO

paolo
 
Can you contact the presenter and ask [citation needed]?
 
:ar15:Was he talking about frequent diving or marijuana use. Sounds like the end game is the same, better keep it on the low down or some group out there will soon make the correlation and our sport/passion will become illegal. I can already see outlaw gangs of divers meeting discreatly (sp) in out of the way dive sites to get their fixes. Bootleggers will be transporting tanks of compressed gasses from contraband compressor ownwers. If you think helium is costly now, just wait and see. :auto:
 
...NOT talking about technical or commercial divers (nor about divers who have experienced DCI/DCS in the past), but simply people who dive somewhat regularly at recreational depths. He claimed that in this group there is peer-reviewed (documented) evidence of short-term memory loss, lessening of high-cognitive functions, ..., and higher susceptibility to depression and mental illness. This sentence was taken verbatim, so I could enter it again on this forum.HB

Hi HB,

This is an area of interest of mine and there have been a surprising number of studies on the topic over the years. These mostly involve commercial/military/technical divers, many of whom had sustained neurological DCS.

Some work has been done with sports divers without histories of DCI and some of this has shown gray & white matter lesions, impairment of neuropsychological function, and abnormal EEGs & MRIs. For better or for worse, for just about every study that finds abnormalities there is another that finds nothing of concern. The following is a smattering of those reporting “positive” findings:


1. Undersea Hyperb Med. 2011 May-Jun;38(3):197-204.

Neuropsychological deficits in scuba divers: an exploratory investigation.

Kowalski JT, Varn A, Rottger S, Seidack S, Kahler W, Gerber WD, Andrasik F, Koch A.

German Naval Medical Institute, Kronshagen, Germany.

CONCLUSIONS: The findings support the proposed possibility that minimal cerebral lesions occur after diving even without DCS. Further studies with this highly selective population of very experienced divers using more elaborate neurocognitive and neuromotor tasks seem warranted.

2. Ann Intern Med. 2001 Jan 2;134(1):21-4.

Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers.

Schwerzmann M, Seiler C, Lipp E, Guzman R, Lövblad KO, Kraus M, Kucher N.

Swiss Cardiovascular Center Bern and University Hospital.

CONCLUSIONS: Regardless of whether a diver has a patent foramen ovale, diving is associated with ischemic brain lesions.

3. Eur Neurol. 1999;42(4):194-9.

Magnetic resonance signal abnormalities and neuropsychological deficits in elderly compressed-air divers.

Tetzlaff K, Friege L, Hutzelmann A, Reuter M, Höll D, Leplow B.

German Naval Medical Institute, Kronshagen, Germany.

Abstract
We investigated the association between MR signal abnormalities of the central nervous system, neuropsychologic performance and exposure indices in 20 experienced elderly compressed-air divers who had no history of neurological decompression illness (DCI). Results of MRI of the brain and psychometric testing were compared with 20 matched healthy commercial employees who never dived: 60% of the divers and 45% of the controls had hyperintense MR abnormalities. Among divers, both the number and the size of abnormalities correlated with hours diving in the deep air-diving range of 40-60 m (p < 0.05). Divers' mental flexibility and visual tracking performance were decreased in comparison with controls (p< 0.05 and p < 0.01). Divers thus are at risk of detrimental long-term effects of compressed-air diving on the central nervous system even in the absence of a history of neurological DCI.

4. Lancet. 1995 Jun 3;345(8962):1403-5.

Central nervous system lesions and cervical disc herniations in amateur divers.

Reul J, Weis J, Jung A, Willmes K, Thron A.

Department of Neuroradiology, Technical University, Aachen, Germany.

Abstract
Permanent neuropsychological changes such as memory disturbances and depression have been found in professional divers, even in those who have never had decompression sickness. The changes are probably the result of intravascular gas bubbles insufficient to cause acute symptoms. We examined amateur divers with long histories of self-contained underwater breathing apparatus diving by magnetic resonance imaging and compared them with normal controls. Hyperintense lesions of the subcortical cerebral white matter and degenerative changes of the cervical disks were significantly more common in the divers. 27 of 52 divers had a total of 86 focal hyperintensities versus 10 of 50 controls with 14 focal hyperintensities (p < 0.01). 32 divers had at least one degenerated intravertebral disc versus 9 controls (p < 0.0001). These results suggest that amateur divers are at risk of accumulating lesions in the central nervous system and in cartilage.


There are a number of important points to bear in mind when thinking about such findings, including:

1. There are no well-controlled studies that substantiate that scuba actually causes these abnormalities.

2. Assuming that these abnormalities in fact are dive-related, it is not known at what point these changes might be expected to occur in sports divers, e.g., depths, times, number of lifetime dives, temperatures.

3. The clinical significance of these abnormalities of brain is often unclear. In many cases, they are &#8220;silent,&#8221; that is, they don&#8217;t seem to be adversely impacting neurocognitive status. And in most cases where they do seem to have an effect, the impact is trivial in any real world sense.

BTW, I am aware of no studies in respected, peer-reviewed journals that suggest an increase in psychiatric disorder (mood disorder or any other) in sports divers without histories of DCI.

This is a complicated subject and much remains unknown. While it&#8217;s being sorted out, IMHO there is no reason for alarm. I have been aware of such studies for decades and haven&#8217;t changed my diving practices one iota solely as a result of them.

The recreational diver who carefully follows customary safe diving protocols appears to be at little meaningful risk of scuba-related cerebral damage or dysfunction even over a very long period of regular participation.

Regards,

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.
 
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Well, that explains a LOT about me! Seriously, I would also want to look at the positive effects of regular recreational diving. My blood pressure was 98/76 the other day. I attribute some of that to regular diving. Diving relaxes me very much and lowers any stress I might feel. Of course having a "job" I love and not being married may also affect that!
 

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