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I came across a forthcoming article, Supertaskers: Profiles in extraordinary multitasking ability, which caught my attention even though it had nothing to do with hyperbaric oxygen or the neurologic conditions we treat at Atlanta Hyperbaric. Other studies have shown that cell phone usage while driving increases accident rates, braking time, object detection etc., i.e., generally increases driver error.    But, many people believe that they can use a cell phone while driving and it doesn’t impair them at all.  These authors looked at 200 college undergraduates to determine just how many of them really could drive unimpaired while talking on a cell phone.

The students took the operation span (OSPAN) test of executive attention, which requires memorizing items and recalling them in the correct order while concurrently performing distracting math problems.  They also performed a driving test in a simulator.  The simulation consisted of freeway driving in traffic while being monitored for braking time and distance from vehicles slowing in front of them.

Overall, participants did significantly worse when doing the two tests at the same time for brake reaction time, following distance, memory performance, and math performance.  But, three men and two women (2.5%) scored in the top 25% on the memory and driving tests and stayed in the top quartile on all measures when talking and driving at the same time. Their memory scores actually rose 3% while multitasking.  The other students showed a 20% increase in braking time, 30% poorer ability to keep pace with traffic, 11% worse memory performance, and 3% lower math scores.

The researchers suggested that these rare “supertaskers” have a genetic or biological advantage rather than simply being more experienced at driving while on the cell phone.  They believe supertaskers could provide information on the nature of cognition in multitasking. Nevertheless,  most of us exhibit a significant decrease in ability when we try to perform two tasks at the same time.

Robots are transforming medicine.  You can find them now in the operating room, the cardiac cath lab and the radiation oncology department.  So, when I came across a robot study used for stroke rehabilitation from the recent American Stroke Association meeting, I was intrigued.  Stroke rehabilitation is, after all, what we do at Atlanta Hyperbaric.

The study patients consisted of 127 stroke survivors at the Veterans Hospital in Providence, Rhode Island who were about two years out from their strokes.  The study patients were divided into three groups: robot-assisted rehabilitation, human-assisted rehabilitation and a control group who received ordinary care but without rehabilitation.  Keep in mind, this study looked at patients who had their strokes a long time before, so rehabilitation is not normally given this late.  The treatment groups had three one-hour sessions with either a human or a robot weekly for 12 weeks.  At 36 weeks of follow up, the treatment groups had “fairly modest” but statistically significant improvement compared to the controls and no difference in results were seen between the robot-assisted and human-assisted groups.

The authors made a disappointing observation to explain their disappointing results: “there’s very little available for people with chronic stroke.”  I guess they never heard of hyperbaric oxygen.

Every patient at Atlanta Hyperbaric gets his blood pressure taken. Measuring a patient’s blood pressure has become a ritual part of the medical examination since the early twentieth century and it didn’t take long to discover an association between high blood pressure and cardiovascular disease. I find it remarkable that after a hundred years of study, researchers are still discovering fundamental truths about this simple and routine medical test.

English researchers just reported that visit-to-visit variability of a patient’s blood pressure over time may be a stronger risk factor for stroke than average blood pressure. The authors looked at blood pressure measurements from four separate studies of patients who had been carefully checked for many years following a stroke or TIA. Overall, more than 10,000 patients had been followed. The researchers found that a high average systolic pressure was a weaker predictor of subsequent stroke than a large variability in systolic pressure over repeated measurements. The risk of stroke of those with the most variable blood pressure compared to those with the least variable blood pressure ranged from 1.78 to 4.84 across the four study groups.

In a companion study, different classes of anti-hypertensive drugs had different abilities to smooth out this variability in blood pressure. The researchers reviewed hundreds of drug trials for treatment of hypertension and discovered that calcium channel antagonists reduced blood pressure variability but ACE inhibitors and Beta blockers actually increased variability. Perhaps even more importantly, it looked like patients treated with the calcium channel antagonists had fewer strokes.

The authors concluded that, “To prevent stroke most effectively, blood-pressure-lowering drugs should reduce [average] blood pressure without increasing variability; ideally they should reduce both.”

Do these studies mean that physicians should be changing the way they treat and monitor their patients with hypertension? At least physicians need to start looking at this issue. It may not be enough just to reduce average blood pressure anymore.

Recovery from stroke is a major effort of Atlanta Hyperbaric.  Hyperbaric oxygen resupplies blood flow to the stroke penumbra, which leads to direct recovery of functional brain tissue, among other things.  Rehabilitation from stroke generally depends upon brain plasticity, or the ability of the brain to remodel brain cell connections in order to compensate for tissue death.  This brain remodeling activity occurs  through repetitive experience.  Exploring video games as a way to engage a stroke patient in an entertaining but repetitive fashion seems like a potentially helpful approach.

Researchers at the University of Toronto presented a study last month at the ASA stroke conference of use of the Nintendo Wii for stroke rehabilitation.   Twenty-two patients with recent mild-to-moderate stroke enrolled in the study.  The age of the patients averaged 61. All had some weakness in at least one of their arms, but were able to touch their chin and knee.  After playing for two weeks, the participants were able to shave off time from certain daily activities compared to controls who did not play the Wii.

In addition to conventional rehabilitation, half performed recreational therapy — playing cards and Jenga — and half played two Wii games, tennis and Cooking Mama.  Cooking Mama uses movements that simulate cutting a potato, peeling an onion, slicing meat, and shredding cheese — for eight one-hour sessions over two weeks.  A similarly high number of patients in each group completed all eight sessions — 90% with Wii and 80% with recreational therapy.

Only the patients in the Wii group significantly improved their fine motor function, measured using the Wolf Motor Function Test, which times patients while they perform daily activities, like grabbing a can of soda or folding a towel.  After adjustment for age, baseline functional status, and stroke severity, participants in the Wii group did significantly better on the test than the controls by 7.4 seconds.  Improvements of 2 seconds are believed to be clinically relevant.
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San Antonio hosted the American Stroke Association’s International Stroke Conference this week. I didn’t attend but my colleagues at Medpagetoday came through again, with extensive coverage, including video.

The conference reported hundreds of studies on stroke, but not one involved hyperbaric oxygen. Although academics are quick to demand more studies to prove the utility of hyperbaric oxygen for any role in the treatment of stroke, either acutely or for rehabilitation, no one is willing to fund the research. Main stream opinion about hyperbaric oxygen involves circular reasoning: hyperbaric oxygen for stroke treatment, though promising, is unproven, therefore, more research is needed before using it for stroke therapy. But, no funds are available for research because hyperbaric oxygen is unproven. As I’ve discussed previously, the decision to treat a patient should be based on a cost-benefit analysis of the available information and not on an arbitrary standard of proof. After all, there can never be enough data.

Although the favorite topic of Atlanta Hyperbaric never came up at the ASA meeting, researchers reported many important findings. Most of the studies would probably only interest professionals, but a few had more general appeal:

Anything more refreshing than a cup of coffee in the morning? If so, perhaps you should reconsider.

Maybe coffee helps prevent strokes: Based on a 12-year study of 9,978 men and 12,254 women from the U.K., the overall risk of stroke was 30% less in those who drank at least one cup of coffee a day. Making statistical adjustments for other stroke risk factors did not change the overall results.

Surgery versus stenting: The first report from the CREST study, which was a multi-center trial of carotid endarterectomy compared to angioplasty and stenting, came out about even for the two procedures. Much more analysis of the data will be forthcoming, but it looks like angioplasty with stenting is about as safe and effective as the older, better studied endarterectomy.

Stroke patients may be getting younger: In the greater Cincinnati area during 2005, the average age of patients presenting with a first stroke was 68.4, which had dropped from 71.3 in 1993 and the percentage of patients with stroke younger than 45 increased from 4.5% to 7.3%. The speculation may be that incidence of stroke risk factors such as diabetes, hypertension, and obesity is increasing among younger people.

Get married: In a 34-year follow up study of about 10,000 men, an Israeli researcher reported that single men had a 64% increased risk of stroke. But, men who reported unsuccessful marriages had strokes at just as high a rate as single men. Speculation ranged from the benefits of having someone remind you to take medicines or avoiding unhealthy food to having someone get you to the hospital in the event of symptoms.

Don’t just glance at the title and then ask, “Is he off his rocker?”  “What’s in the water cooler at Atlanta Hyperbaric?”  No, I said oxytocin, not OxyContin®.  The first is a hormone, sold under the trade name of Pitocin®, and the second is an opioid pain killer with a habit-forming potential. It’s an easy mistake to make, unless you happen to be a pharmacist or are otherwise familiar with these drugs.

Oxytocin was first isolated in 1953 and has been available to physicians at least since I was a medical student in the 1960’s. Oxytocin is commonly used by obstetricians (as a  ”pit drip”)  in the induction and management of labor and delivery.  Of course, just because a drug is old and familiar, doesn’t make it good, bad, safe or dangerous.  But, old drugs are relatively well studied and predictable, so it is always welcome news when researchers start looking at new indications for an old drug.

Oxytocin has profound and complex behavioral effects, largely documented in animals, but increasingly observed in people.  In humans, oxytocin induces trust, increases generosity, but also  stimulates envy and gloating.  Oxytocin has even been called the love hormone.  Autism is characterized by three symptom categories: speech and communication abnormalities, social functioning impairments and repetitive behaviors and restricted interests. Plasma oxytocin levels have been reported to be abnormally low in autistic patients, so it is not surprising that this powerful drug is also being tried as an autism treatment.

This week a group of French researchers reported that oxytocin improved the abilities of autistic adults to interact with other people.  The researchers had the patients play a video ball-tossing game, in which the patients threw balls to cartoon characters with three different behavioral profiles:  One player always returned the ball to the patient, another player never returned the ball, and the third player indiscriminately returned the ball to the patient or to other players.  Before oxytocin, the patients threw the ball randomly to all three players, but after oxytocin, the patients preferred to throw to the guy who threw it back to them.

The scientists also measured the patients’ attentiveness to social signals.   Patients looked at photos of faces on a computer and were asked to identify either the gender or whether the face was looking into the camera or away to one side. The focus of participants’ gaze was recorded. Mean time spent looking at the faces, as opposed to elsewhere, was about 20% to 30% greater following oxytocin treatment both in the gender identification and the facial-direction tasks.  The patients also would sometimes look directly at the eyes in the photos, which they never did without oxytocin.

At baseline, mean plasma oxytocin levels were 1.08 pg/mL in patients compared with 7.28 pg/mL in the healthy controls (P<0.0001). Ten minutes after intranasal oxytocin in the patients, their plasma levels were still only 2.66 pg/mL, yet despite the persistent shortfall in plasma oxytocin and substantial individual variability in performance, the lead investigator said, “We demonstrated that oxytocin can promote social approach and social comprehension in patients with autism.”

This study is great stuff.  Of course, it only looked at a few adult patients and researcher biases could have poisoned the well.  But I am encouraged and time will tell whether oxytocin replacement therapy can help autistic patients, children and adults, over the long run.

Another week in the books at Atlanta Hyperbaric and two interesting things happened: First, an article came out on maternal age and autism and second, a patient was referred with chronic Lyme disease.  We, of course, treat autism and keep an open mind about Lyme disease.

The autism study should be much admired by epidemiologists.  The study group comprised nearly 5 million births in California between 1990 and 1999 and more than 12,000 autism cases.  With such large numbers–assuming they are reasonably accurate–the findings should be pretty reliable. Mothers who gave birth when they were 40 or older had a 51% increased risk of having a child with autism compared with those who were 25 to 29, the largest age group.  Paternal age effected autism rates only if mothers were younger than 30.  Maternal age, however, accounted for just 4.6% of the autism incidence while over the same time frame, overall autism incidence increased by a factor of 6.  In other words, according to the authors, rising maternal age definitely seems to contribute to the increase of autism cases, i.e., is a risk factor for autism, but only accounts for a fairly small proportion of all the increased number of autism cases being seen.

Chronic Lyme disease is about as controversial a topic as there gets in Medicine.   Dr. Allen C. Steere, the discoverer of Lyme disease, reported death threats in 2001 because he took a very public position that people diagnosed with chronic Lyme disease generally don’t need to be treated with more than a month of antibiotics; because of his stature and reputation, many insurers stopped paying for the antibiotic treatments and State regulatory authorities started going after physicians writing the prescriptions.  Dr. Steere’s position in July 2008 on chronic Lyme disease appears unchanged.

Regular readers of this blog have probably figured out by now that I am a libertarian.  For the uninitiated, my definition of a libertarian is basically someone who believes that all problems on Earth are caused by government.  All problems.  Even dog fleas (see page 7.)  If a patient wants IV antibiotics for chronic Lyme and a physician wants to prescribe them, I don’t see why the government needs to stick its metaphorical nose into the issue.  I may not believe the antibiotics will have any beneficial effect and, indeed, I suspect chronic antibiotics have harmful effects under these circumstances, but I won’t condemn either the physician or his patient.  To me, the marketplace solves this problem better than any bureaucrat and I believe the market never errs, if allowed to be free.  And, please don’t bring up the wastefulness argument because that spills over into another topic entirely and has nothing to do with whether a doctor should be allowed to prescribe antibiotics when the State says he shouldn’t.

If you think that treatment of chronic Lyme disease with antibiotics is controversial, you can imagine the literature on hyperbaric oxygen treatment for this condition.  At least there have been no death threats: It is uncommon for insurance companies to pay in the first place and no one proposes–yet–to interfere with this doctor-patient relationship.

Over the years, I have treated with hyperbaric oxygen about half a dozen patients who carried the diagnosis of chronic Lyme disease.  These patients all had positive blood tests for Lyme, several had documented erythema chronicum migrans, all had multiple courses of both intravenous and oral antibiotics and all continued to have long standing complaints of severe fatigue, sleep disturbance, headaches or cognitive problems.  In other words, all of these patients had acute Lyme disease at one point in their lives and then developed chronic, nonspecific symptoms.  Everyone of these patients has sworn to me that the hyperbaric oxygen treatment helped their symptoms.

Is there any scientific evidence that hyperbaric oxygen helps patients with chronic Lyme disease? I am only aware of one study, and the only thing I can make of it is that hyperbaric oxygen harmed no one–rarely does it ever–and more than 80% of the patients claimed their symptoms improved.  There is at least a scientific rationale behind the use of hyperbaric oxygen treatment: The spirochete that causes Lyme disease is sensitive to a high-oxygen environment.   Under hyperbaric conditions, there can be no place in the human body for the Lyme spirochete to hide from oxygen levels that should be able to kill it.  Let’s see how my new patient does.

Earlier this week, The Lancet, the prestigious British medical journal, published the following short retraction:

It doesn’t get any more serious in the world of science.  Ordinarily,  a scientist who realizes an error in one of his published papers simply stops referring to the report and allows it to die an unceremonious death.    Occasionally, a scientist of especial probity will voluntarily publish a retraction and explanation.  But, it is distinctly unusual for someone to be accused of scientific fraud, much less twelve years later.    What usually follows is a series of denials and recriminations, finger pointing and objurgation, though mostly in-house, because science usually affects only scientists.  The big controversies that spill over to the general public–and this one is the biggest in years–typically leads to great fonts of oratory from people who don’t know much about science,  but who do hold the reins of power.  Heaven forfend, we will not see any of our wise Solons in Washington pass new laws or regulations to protect us from future trespasses.

Of course, we treat autistic kids at Atlanta Hyperbaric.  And, they are very dear to me.  As I’ve said many times before, I would love to have a practice that ONLY treats children, for the selfish reason that it makes me feel good to help out kids who will be around long after I’m gone.  Consequently, this English dust up hits pretty close to home.

Few minds will be changed by The Lancet retraction.  Even though mainstream medicine subsequently brought forward a large volume of research casting doubt on any association between vaccines containing mercury preservatives and autism, The Lancet report did much to propel the controversy.  People took sides and, depending on their view of the dispute, kids paid the price either by going unvaccinated and risking mumps, measles and rubella or by getting vaccinated and risking autism.   The great gods of government stepped in and took Thimerosal, the main mercury-based preservative in the United States, off the market.   Litigation has raged, including a recent plaintiffs’ decision by the Georgia Supreme Court. [American Home Products v. Ferrari, 284 Ga. 384, 668 S.E.2d 236 (2008.)]  I suspect that hundreds of millions (more?) of dollars have been spent on this controversy.

What can we learn from this mess?  We already knew that scientists were human and subject to the same character flaws as everyone else.  We also knew what side the weight of scientific evidence fell in this particular instance.  So I guess we really don’t learn anything.  More scandals will occur, more pundits will opine, more people will be injured and more money wasted.  And, God help us, more politicians will solve our problems.

Atlanta Hyperbaric helps kids with traumatic brain injury, but for various reasons the problem tends to be understated.  As I discussed last week, the terminology we use can be confusing because parents and physicians alike often downplay a mild traumatic brain injury by calling it a concussion.  This week I mulled over the problem and found a report that points to some other subtleties of children after traumatic brain injury.

In a well controlled and designed study, the researchers looked at kids who came in the emergency room at Nationwide Children’s Hospital, Columbus, Ohio, who had head injuries and compared them with a control group of kids with arm or leg fractures.  The head-trauma group was carefully defined to include only mild traumatic brain injury with unconsciousness of less than 30 minutes.  All the children were reassessed at 3 weeks, 3 months, 6 months and a year.

Although it was not surprising, persistent symptoms such as amnesia, vomiting, headache, and dizziness occurred more often in the head trauma kids than in the fracture kids.  What did surprise me was how often the fracture kids had these kinds of brain-injury type symptoms.  The authors pointed out that all traumatic events will create some psychological problems but, obviously, if the whole issue were psychological, no differences between the head-injury group and the fracture group would have been found.  By the same token, if no psychological problems were involved, the fracture group would probably have had no long-term symptoms.

The authors were able to identify a group of kids at high risk for persistent brain-injury symptoms.  When they ranked the kids by severity, those in the high-severity group were three times more likely to have persistent symptoms.

Which people suffer long term problems following a bump on the head?  We frequently have to answer that question at Atlanta Hyperbaric and the current use of medical terms may add to the confusion.  At Atlanta Hyperbaric, we follow the Centers for Disease Control’s guidelines for the definition of Mild Traumatic Brain Injury (table.)

According to CDC, traumatic brain injury occurs 1.5 million times annually, with 50,000 deaths and 230,000 hospitalizations. Patients with mild traumatic brain injuries frequently suffer long-term memory problems as well as psychological and personality changes. At Atlanta Hyperbaric we aim to prevent and reverse these symptoms.

The real problem at Atlanta Hyperbaric comes up when someone says they had a concussion. Although concussion is also a medical term of art with a consensus definition that the CDC publishes, many patients and physicians use the terms “concussion” and “mild traumatic brain injury” interchangeably, and some use these terms in a confusing manner that suggests that a concussion is nothing to be concerned about.

This week I came across an interesting study that addressed this very issue. Among children admitted for a traumatic brain injury, those who were told they had a concussion were discharged significantly earlier and returned to school sooner than those who were not given the label. The authors concluded, “We suggest that the [concussion] label itself conveys a message and also directs outcomes….If we want to encourage full reporting with subsequent adequate management and convalescence, perhaps we should use the term ‘mild traumatic brain injury.’”

Some experts disagreed with this conclusion and I can understand why some would consider the whole issue a tempest in a teapot. I don’t. Hyperbaric oxygen helps these patients avoid long-term consequences. If telling parents that their child suffered a mild traumatic brain injury rather than a “mere” concussion helps to encourage further diagnosis and treatment, then let’s call a spade a spade.