I recently read a fascinating book, The Brain That Changes Itself by Norman Doidge. He describes case histories and research indicating that the brain is far more malleable than we once thought. We used to think each function was localized to a small area of the brain and if you lost that area of brain tissue the function was gone forever. We once thought you couldn’t teach an old dog new tricks. Now we know better.
Learning a new skill actually changes the structure and function of the brain, even into old age. If you exercise one finger, the area of the brain devoted to that finger enlarges. The old concept of dedicated brain areas for specific functions no longer holds. Areas of the cortex that normally process vision can learn to process totally different inputs such as hearing. This is what happens with blind people: their hearing skills are enhanced when new neural connections for hearing invade the disused visual cortex. They may not actually have better hearing acuity, but they have learned to pay more attention to auditory input and to use it to build up a representation of the world around them.
One of the more intriguing experiments he describes was in monkeys. When sensory input nerves to one arm were severed, the monkey stopped using the arm, even though the motor nerves were intact. When the good arm was put in a sling, the monkey started using the impaired arm again. When both arms were deprived of sensory input, the monkey used both arms. (more…)
In the comments to a previous blog entry, a chiropractor made the following statements:
1. Chiropractic is a science.
2. Chiropractic is based on neurology, anatomy and physiology.
3. Chiropractors are doctors of the nervous system.
4. Chiropractic improves health and quality of life.
I offered to write a blog entry on the “science” of chiropractic, and I asked him, both in the comments section and by personal e-mail, to educate me first by providing me whatever evidence he could find to support those claims. I never heard back from him, so I was left to do my own research as best I could. Here’s what I found.
Is chiropractic a science? No.
In 1895, a magnetic healer named D. D. Palmer adjusted a deaf man’s back and allegedly restored his hearing. Generalizing from this one case, he reasoned that “A subluxated vertebra… is the cause of 95 percent of all diseases. …The other five percent is caused by displaced joints other than those of the vertebral column” (more…)
There is a new industry offering preventive health screening services direct to the public. A few years ago it was common to see ads for whole body CT scan screening at free-standing CT centers. That fad sort of faded away after numerous organizations pointed out that there was considerable radiation involved and the dangers outweighed any potential benefits.
Now what I most commonly see are ads for ultrasound screening. In fact, I am sick and tired of finding them in my mailbox and between the pages of my local newspaper. Ultrasound is certainly safe, with no radiation exposure. It sounds like it might be a good idea, but it isn’t.
Life Line Screening advertises itself as “America’s leading provider of quality health screenings.” They offer “4 tests in less than 1 hour – tests that can save your life.” They travel around the country, setting up their equipment in community centers, churches, and YMCAs. For $129 you get ultrasounds of your carotid arteries, your abdominal aorta, your legs, and your heel bone. They mail you your results 21 days later. (more…)
When I recently wrote about glucosamine, I discussed the evidence up through the New England Journal of Medicine study of 2006, which I thought was a pretty definitive study showing that neither glucosamine, chondroitin or a combination of the two was more effective than placebo. Subsequent studies have continued to fuel the controversy. One 2007 study showed that glucosamine sulfate was better than placebo for knee osteoarthritis. Another 2007 study showed that glucosamine HCl and chondroitin, with or without exercise, were no better than placebo for knee osteoarthritis. Sources like the Natural Medicines Comprehensive Database believe the evidence favors glucosamine sulfate but not glucosamine hydrochloride.
A new study was published 19 February 2008 in the prestigious Annals of Internal Medicine. It is arguably the best study to date, and may shed some light on the controversy. Carried out in the Netherlands in a primary care setting, it studied 222 patients with hip osteoarthritis over a 2 year period. Half the patients took glucosamine sulfate 1500 mg a day; half took a placebo. They concluded that glucosamine sulfate was no better than placebo in reducing symptoms and progression of hip osteoarthritis. (more…)
You’re a patient. That cold just isn’t getting better and you have purulent drainage from your nose, and your face hurts and your teeth hurt. You probably have sinusitis, right? You go to a doctor to get an antibiotic.
You’re a doctor. Deep down, you know there’s a good chance the patient has a self-resolving condition. You’d rather not do x-rays on every patient who presents with these symptoms, because x-rays are expensive, expose the patient to harmful radiation, and they are not always accurate. You could puncture the sinuses and take a sample for bacteriological culture, but that’s expensive, painful, and the patient would NOT appreciate it. The patient may not really need treatment, but you want very much to do something to help. If you can find a reason to give the patient an antibiotic, you can feel that you have done something worthwhile. Antibiotics don’t work for a viral infection, but you rationalize that you’re not 100% sure it’s not bacterial, and that sometimes a bacterial infection develops superimposed on a viral infection and mild bacterial infections can develop into severe ones with complications, and maybe you could ward that off. You convince yourself that it really would be prudent to prescribe an antibiotic. Both you and your patient are happy. The patient gets better. You remember this pleasant experience and are reinforced to do the same next time.
Maybe that’s not such a good idea.
A recent study in JAMA showed that antibiotics were not superior to placebo for treating bacterial sinusitis diagnosed by the clinical criteria used by many primary care physicians. There is a growing concern that we have been overtreating sinus infections. Recent research has also shown that we were overtreating ear infections in children, that many of them resolve just as fast without treatment. That doesn’t mean antibiotics should never be used for ear infections. There are now guidelines for using age and clinical presentation to determine which children to treat and which ones can be safely observed without antibiotics. Most of these observed ear infections will resolve but some will eventually require antibiotics too. The situation with sinusitis is similar: most patients may not need antibiotics, and we’re trying to thrash out better criteria for identifying those who will.
Critics point to this kind of thing as a defect of conventional medicine. We use treatments that are not based on good evidence. We do things for years and then find out we were wrong. New studies are constantly contradicting older studies. We keep changing our minds. (more…)
Patients with heartburn are often diagnosed with GERD (gastroesophageal reflux disease) and treated with a drug called a proton pump inhibitor (PPI) to reduce stomach acid production. It is pretty effective, but it doesn’t always work. When it doesn’t, standard practice has been to double the dose of PPI. Doubling the dose only improves symptoms in 20-25%. Most patients who fail the single dose turn out to have normal esophageal acid exposure, or “functional” heartburn. In other words, the symptoms appear to be due to something other than excess acid – so it really may not make much sense to double the PPI dose. What else could doctors try?
How about acupuncture? A recent clinical trial compared acupuncture to doubling the proton pump inhibitor dose in refractory heartburn. (more…)
There is an organization that calls itself The International Network of Cholesterol Skeptics (THINCS). Its members “thinc” they are smarter than the average doctor. They “thinc” that cholesterol has nothing to do with cardiovascular disease and that we have been deluded into waging a “cholesterol campaign” for which the scientific evidence is non-existent. They say, “What we all oppose is that animal fat and high cholesterol play a role.” I find even the wording of this statement problematical: one does not usually hear scientists “opposing” matters of fact or non-fact. They go on to say, “The aim with this website is to inform our colleagues and the public that this idea is not supported by scientific evidence; in fact, for many years a huge number of scientific studies have directly contradicted it.”
They tell us about those contradicting studies; but they don’t tell us about the flaws in those studies, they misrepresent some of the results, and they don’t tell us about the many good studies that support the cholesterol/heart link. The issue is a complex one, and it is easy to find studies to support any claim. Good science is about weighing all the evidence pro and con before reaching a conclusion. As far as I can see, these folks have cherry-picked the literature to support an agenda. They seem to have a vendetta against statin drugs in particular.
The website solicits complaints of adverse effects from statin drugs. It features a petition to the WHO that you can sign requesting an investigation of statin side effects. It alleges that lowering cholesterol endangers the elderly. It provides “what the medical journals and newspapers won’t let you hear” – letters and papers that have been rejected for publication. It lists books, published papers and talks by its members. It solicits financial contributions to the cause.
This movement seems to have started with Uffe Ravnskov’s book The Cholesterol Myths, published in Swedish in 1991 and in English in 2000. That book has been severely criticized, for instance in The Skeptic’s Dictionary , where Bob Carroll points out some of the distortions and deceptive techniques found in the cholesterol skeptics’ arguments. A typical claim: “Cholesterol is highly protective against cancer, infection and atherosclerosis” and “high TC [total cholesterol] and LDL levels are beneficial at all ages.” These statements are not only false, they are potentially dangerous to the health of those who believe them. (more…)
Glucosamine and chondroitin, used separately or together, are among the more popular diet supplements. They are used widely for osteoarthritis, especially of the knee, and have been better studied than most other diet supplements. But do they really work?
The journal of my medical specialty, American Family Physician, recently published an article about the use of dietary supplements in osteoarthritis. They gave a “B” evidence rating to both glucosamine and chondroitin. This means there is inconsistent or limited-quality patient-oriented evidence. They recommended the use of glucosamine sulfate, saying, “Overall, the evidence supports the use of glucosamine sulfate for modestly reducing osteoarthritis symptoms and possibly slowing disease progression.” They did not exactly recommend chondroitin, although they said it “may provide modest benefit for some patients.”
I remain skeptical. And so does R. Barker Bausell, who devoted several pages of his book Snake Oil Science to an analysis of the research on glucosamine and chondroitin. (more…)
Over the last few months, I have had a truly surreal experience. It started when I noticed a two-page full color spread in TV Guide magazine advertising a product called Akavar 20/50. It contained the same claims that so many bogus weight loss products do: eat all you want and still lose weight. What attracted my interest was their highlighted statement: “We couldn’t say it in print if it wasn’t true!”
I laughed out loud. Anyone can say anything in print until they get caught. These diet ads all say things that aren’t true, and the FTC can’t begin to catch them all.
The ad describes research results they call “staggering.” They have scientific documentation that 23 out of 24 patients using Akavar’s active ingredient lost weight. They also described a controlled, randomized clinical trial of their actual product in which 23 out of 24 patients lost “a substantial amount of weight.” Two questions immediately came to mind: why were the numbers the same in both studies, and if a single active ingredient worked just as well, why was there any need to develop the Akavar formulation?
There was a toll-free number where I could call for further information. I called and asked for the citations of the two studies they referred to. The man who answered was flummoxed: “No one’s ever asked me that before.” He had to go for help. Finally he came up with the names of two journals and no further information.
I searched PubMed for anything in either of those journals that might even remotely be the studies they described, and I couldn’t find anything. I wrote the company’s customer service representative and asked for more information. And then the real fun began. Here are the actual e-mails for your delectation: (more…)
Some time ago, I learned that a Seattle chiropractor, Johanna Hoeller, had been featured on a local TV newsmagazine show. She was so proud of the segment that she had it posted on her web page for all to see. Unfortunately it is no longer there, so I’ll have to tell you what it showed.
She demonstrated her techniques on-camera. She put one wrist on top of the other, held them about an inch away from the patient’s neck and proceeded to produce a cracking sound in her own wrists without touching the patient in any way. The patient claimed to have felt something and to have experienced relief of pain.
The funniest part was when the news crew showed her their video of her performance and pointed out that she had not touched the patient. She appeared to be surprised and responded, “My whole thing is that I’m touching.”
Hoeller practices a form of chiropractic called NUCCA (National Upper Cervical Chiropractic Association). It’s a variant of the hole-in-one idea first proposed by B.J. Palmer, the son of the inventor of chiropractic, D.D. Palmer. Supposedly if you adjust the top cervical vertebra, that will correct any problems in the entire spinal column. Fix one and you fix them all. There is no credible evidence for any of NUCCA’s claims.
So here’s a woman “pretending” to do something that doesn’t work even if you actually “do” it. A little knowledge of psychology easily explains why she has so many satisfied patients. It’s even easy to understand how her experiences may have genuinely convinced her she is doing something effective. What I have trouble imagining is how she first got the idea to try treating without touching in the first place! (more…)