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I bring up this issue because we supposedly have a free-market medical system and the Chinese–well, they’re communists.  Has the free market failed yet again?

Actually, I’m one of those true believers who thinks that markets never fail.  So, my a priori answer to this Sino-American conundrum is that we don’t have a free market in medicine and the Chinese probably don’t withhold cheap, harmless therapy that seems to work even though scientific evidence is less than certain.

I only recently came across this English-language review of the Chinese medical literature on the subject of hyperbaric oxygen for the treatment of cerebral palsy and my supposition about Chinese medical policy, at least, was born out.  This particular review confined itself to neonatal ischemic patients and the researchers, though from England, had an obvious command of the Chinese language. The authors found 20 Chinese-language reports of randomized, or what the authors called quasi-randomized, studies; quite a few other hyperbaric oxygen studies  for cerebral palsy did not meet the authors’ inclusion criteria and had to be excluded from the analysis.

Overall, the patients treated with hyperbaric oxygen fared better than the ones who did not receive hyperbaric oxygen.  Here are the authors’ conclusions in their own words:

“Treatment with hyperbaric oxygen possibly reduces mortality and neurological sequelae in term neonates with hypoxic-ischaemic encephalopathy. Because of the poor quality of reporting in all trials and the possibility of publication bias, an adequately powered, high quality randomised controlled
trial is needed to investigate these findings. The Chinese medical literature may be a rich source of evidence to inform clinical practice and other systematic reviews.”

This conclusion is hard to quibble with: Maybe hyperbaric oxygen works and more study is needed to say for sure.  But I find it curious that the Chinese are willing to treat their brain-injured babies with hyperbaric oxygen whereas the American government–or at least Medicare and Medicaid, for the most part–refuses to pay for hyperbaric oxygen treatment of brain injury.

From time to time, Atlanta Hyperbaric gets a child referred for hyperbaric oxygen therapy who has had a stroke.   Although most of our stroke patients are adults, and older adults at that, it seems like awareness of stroke in children is increasing.  Not long ago, the American Heart Associations issued guidelines for the diagnosis and treatment of childhood stroke.  These guidelines emphasize the differences in pediatric and adult strokes.  For example, most of the kids with stroke have congenital heart disease or sickle cell disease.  Most adults have atherosclerosis.  Many of the kids have had perinatal strokes, that is, strokes just before, during or shortly after birth, like our most recent child referred to Atlanta Hyperbaric.  Children with stroke often present with seizures, whereas adults do so infrequently.  Clot busting drugs like TPA have not been studied in children because it is so rare to diagnose a child within three hours of the onset of stroke.

Now it turns out that the incidence of childhood stroke may be more frequent than once believed.  A University of California group took a look at Kaiser Permanente records of more than two million children to determine the incidence of stroke in this population.  Stroke is still pretty rare in children, 2.4 per 100,000 person-years, but these finding are roughly double the incidence previously reported.  Because the authors searched radiology reports as well as discharge diagnoses, they were able to confirm a lot more cases.

These data say nothing about whether the incidence of stroke in children is increasing or that diagnosis is become more accurate.  What we can say, for certain, is that childhood stroke is being recognized more and more.

I believe that hyperbaric oxygen therapy can be of particular benefit to children who have had strokes.  For example, I have seen striking improvement in seizure control in cerebral palsy patients treated with hyperbaric oxygen and would think the same would be true in children with strokes.    Of course, like the cerebral palsy patients, children with stroke have a whole lifetime in front of them.

A few weeks back, I wrote about the animal model of cerebral palsy.  Although animal models have pitfalls, by and large, medicine has often advanced through wise interpretation of these models.  Rats are often used because the scientist can do many experiments on a limited budget.

I always read the Journal of the Undersea and Hyperbaric Medical Society as soon as I receive it each quarter.  So, I must have read this animal study when it came out last year, but alas, I forgot about it.  I came across it again just recently and realized that I ought to make a few comments because this study has findings that are important to everyone interested in cerebral palsy.

The authors performed experiments on 180 rats!  I can hardly imagine recruiting 180 patients for any kind of human study, let alone one that involves hyperbaric oxygen.  In any case, the authors set up the cerebral palsy model in the rats and gave them one hyperbaric oxygen treatment daily for seven days. They carefully examined the hyperbaric-oxygen treated animals and compared them to the untreated ones and found that, within two weeks, neural stem cells had migrated into the cerebral cortex of the hyperbaric-treated animals and that, within four weeks, the treated animals actually had an increased number of neurons, i.e., the hyperbaric-treatment group actually grew brain tissue: the brain had partially repaired itself from the injury.

These results are really nothing short of astonishing.  We know that the brain has limited regenerative powers.  Here, however, after the severe damage caused by the experimental injury, prompt institution of hyperbaric oxygen not only stimulated neural stem cells to migrate into the damaged area, but these stem cells were able to differentiate into actual brain tissue, limiting the overall damage.  To the best of my knowledge, no other intervention of any kind has ever made this claim for the injured brain.

Physicians who treat children with cerebral palsy have to maintain a positive outlook.  I think that’s especially true for those of us who treat patients with hyperbaric oxygen.  We all agree that cerebral palsy cannot be cured.  See here, here or here.  The mainstay of therapy for most of these children is physical therapy, tailored to the individual, to improve strength and mobility.  Controlling seizures, muscle spasticity and other medical problems specific to individual children comprise much of the therapy these children receive.  Many kids with cerebral palsy are fortunate not to have substantial cognitive difficulties and can attend regular schools.  All of these treatments make life better for cerebral palsy patients and their families, but none of them help the underlying neurologic condtion.

Controversy  occurs only if someone claims a certain treatment option improves the underlying neurological condition of cerebral palsy.  Standard treatment, after all, is palliative.  It is awfully odd that hyperbaric oxygen therapy is so harshly opposed by its critics.    Because hyperbaric oxygen is the only option for cerebral palsy that claims to improve the underlying pathology,  it seems to me that such a treatment ought to be embraced.

I have spent a lot of time over the years trying to figure out why hyperbaric oxygen inflames passions the way it does and I know from experience that one of the reasons is economic.  Government and insurance companies have been encroaching on the doctor-patient relationship throughout my career and doctors don’t need much to put them in fear for their wallets.  Hyperbaric oxygen can represent economic competition for physicians who make their living operating or medicating and doctors are all too human when they see their own indispensability challenged.  I’ve found it especially sad, however, that some physicians go out of their way to discourage parents about hyperbaric oxygen for kids with cerebral palsy.  As tough as economic times may be, I like to think that most physicians still have a soft spot for children, especially children who face the problems that cerebral palsy kids do.

In any case, we at Atlanta Hyperbaric love treating cerebral palsy kids.  These kids will still have benefits from my treatment long after I’m gone and I can’t afford to waste any energy over those who are insecure.

Animal models are useful for research in many diseases, including cerebral palsy. Conditions can be controlled with precision, but you can never be certain whether the results of an animal experiment apply to people. Regardless of the uncertainty, the results can be interesting.

Perhaps the most common animal model of cerebral palsy is the so-called hypoxic-ischemic encephalopathy (“HIE”) model in rats. This model has been around about 30 years and is relatively inexpensive to set up. Essentially, the scientist ties off one of the carotids of a week-old rat, then exposes it to low levels of oxygen. The specific protocol may vary a bit in different laboratories, but the model produces a fairly consistent brain injury and most of the young rats survive. Researchers have employed the HIE model to test many different treatment options for cerebral palsy, from stem cells to hyperbaric oxygen.

Dr. John H. Zhang, of Loma Linda University Medical Center, has published a lot of work in the area of hyperbaric oxygen therapy in the HIE model. Much of this work centers around the protective effects of oxygen treatment. For example, a single hyperbaric oxygen treatment following the exposure to low levels of oxygen in the HIE model resulted in a substantial reduction in brain cell death and brain atrophy and even improved motor and sensory function some 6 weeks later.  

It is just about impossible to argue with these results. You can criticize the human trials of hyperbaric oxygen in cerebral palsy by saying that the benefits are due to “group participation effect” or some other fancy term for selection bias. But, you cannot dismiss an animal study with standard clichés. Plainly, hyperbaric oxygen can reduce brain injury in the HIE model. Obviously, this model has limitations, but it’s what we have.

In 2001 the prestigious English medical journal, Lancet, published the only double-blind, randomized study of hyperbaric oxygen for the treatment of cerebral palsy ever performed.  In the ensuing eight years, no one has attempted to extend or even replicate the study, and I doubt that any more clinical research will be done for the foreseeable future.  What happened is a perfect example of, “My mind is made up, so don’t confuse me with facts.”

One of the coauthors of the Collet study, Dr. Pierre Marois, recently wrote a review article (www.jpands.org/vol12no4/marois.pdf ) on the subject of hyperbaric oxygen treatment of cerebral palsy that devoted a large segment to the controversy that still raises blood pressure at its very mention.  On its surface, the Collet study was straight forward:  It was an attempt to randomize children to hyperbaric oxygen treatment and compare them to children in a control group.  The problem, and the controversy, turned out to be the control group.

Because Dr. Marois’ report is freely available and the Collet study is old news anyway, I won’t go into great detail.  To make a valid comparison, both the researchers and patients in the Collet study could not know who was receiving hyperbaric oxygen. Consequently, both the oxygen and control groups had to be subjected to hyperbaric conditions–otherwise it would be easy for a patient to know if he were being treated simply by being able to feel the pressure or its absence.  The treatment group received 100% oxygen at 1.75 atmospheres of pressure and the control group received room air at 1.3 atmospheres of pressure.  In other words, the study compared treatment with hyperbaric oxygen to treatment with hyperbaric air, so it is inaccurate to call the hyperbaric air treatment a placebo.  The results showed that both the children treated with hyperbaric oxygen and the children treated with hyperbaric air showed considerable objective improvement compared to children who received no hyperbaric treatment at all.  But, there was no difference in outcome between the two hyperbaric treatment groups.

The coauthors began to squabble even before the study was published.  According to Dr. Marois, Dr. Collet and the group that funded the study wanted everyone to believe that the patients treated with hyperbaric air were treated with a placebo, so that they could conclude that hyperbaric oxygen treatment for cerebral palsy was no more effective than a placebo.  On the other hand, Dr. Marois pointed out that hyperbaric air is surely not a placebo, and in fact is in common use, with life-saving effect,  for treatment of acute mountain sickness.  Marois believes, as I do, that the Collet study plainly proves the efficacy of hyperbaric oxygen therapy for the treatment of cerebral palsy, although hyperbaric oxygen may not be more effective than hyperbaric air.

I’ve saved the best for last.  The Collet study was done in Canada and Canada has socialized medicine.  On the basis of the Collet study, the Canadian government does not pay for hyperbaric oxygen treatment of kids with cerebral palsy.  The Canadian government does not pay for hyperbaric air for these children either, though based on the Collet study, it seems like it should.  Does anyone think the proposed American socialized medicine scheme will pay for cerebral palsy kids to have hyperbaric oxygen or even hyperbaric air treatment?

Glenn L. Goodhart, M.D., J.D.