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Alleman:
Restoration of all cognitive function is
necessary to return to safe diving. No matter what type
of diving is done, all divers need to have good mental
faculties when faced with an emergency in the water,
whether it is an encounter with marine life or the loss
of air/gas at depth. Any impaired response in these
situations could be fatal.
What are the minimum medical requirements that
must be met by people with a TBI who wish to dive?
Weaver:
Tests such as the sharpened Romberg and
near point of convergence are relatively sensitive in
brain-injured people, but if they are positive, does that
mean the diver can or cannot dive? I don’t think these
tests suggest a definitive answer to the question. I think
whether diving can be endorsed is more a matter of the
symptoms, including how they might change during a
dive and whether they might somehow increase the risk
of a dive emergency.
Regardless, patients who had a moderate or even
severe TBI and want to dive should be assessed by brain-
injury specialists such as neurologists, physical medicine
and rehabilitation specialists, neuropsychologists,
psychiatrists and dive medicine specialists.
In the event of penetrating trauma or if injury to
the temporal lobe occurred, then seizure risk will be
significantly elevated for several years after the injury.
A mild TBI brings a slightly elevated risk of seizure, but
that risk is low. A diver who has recovered from a mild
TBI can probably use nitrox but should perhaps limit
their PO
2
to 1.3 ATA. That being said, I am not aware
of any real evidence about how hyperoxia and prior
brain injury affect seizure risk.
Massey:
The requirements are an ability to think
clearly, no significant anxiety, good attention span,
appropriate insight and judgment for training and no
physical limiting factors.
Alleman:
A normal, thorough neurological
examination would be required for a return to diving.
Cognitive testing would also be advised. For any history
of loss of consciousness, imaging (CT or MRI) should
be considered prior to returning to diving.
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MEET THE EXPERTS
Tony Alleman, M.D., MPH,
is board certified in occupational
medicine and undersea and hyperbaric medicine. He is the
chairman of the Physicians Diving Advisory Committee of the
Association of Diving Contractors International and participates
on an International Marine Contractors Association committee
on diver health. In his practice he performs dive physicals and
treats dive-related disorders for commercial divers. He is the
past president of the Gulf Coast Chapter of the Undersea and
Hyperbaric Medical Society.
Wayne Massey, M.D.,
is a clinical neurologist and professor of
neurology at Duke University Medical Center in Durham, N.C.
He gained significant experience treating divers with serious
decompression illness as a doctor at the U.S. Navy Hospital
in Bethesda, Md. He is a fellow of the American Academy
of Neurology and the American College of Physicians and a
member of the DAN board of directors.
Lindell Weaver, M.D.,
is the medical director of hyperbaric
medicine at Intermountain Healthcare in Salt Lake City, Utah.
He became a diver in 1975, was a U.S. Navy Undersea Medical
Officer for two years and became a diving instructor in the
1980s. He has studied hyperbaric oxygen for brain injury for
years and played a leadership role in U.S. Department of
Defense studies of randomized trials of hyperbaric oxygen for
postconcussive syndrome due to war-related mild TBI.
References
Annegers JF, Hauser WA, Coan SP, Rocca WA. A population-based study of seizures after traumatic brain injuries. N Engl J Med 1998; 338:20-24.
McMahon PJ, et al. Symptomatology and functional outcome in mild traumatic brain injury: results from the prospective TRACK-TBI study. J
Neurotrauma 2014; 31(1):26-33.
Returning to diving following a head injury requires ample time
for a complete recovery and a thorough evaluation by medical
professionals with relevant expertise.
JOE POE