A new study suggests that it may not be uncommon for patients who are in a minimally conscious state to be misdiagnosed as being in a persistent vegetative state. The study underscores the necessity of using standardized and objective diagnostic criteria in diagnosing coma. However, it also leaves some important questions unanswered.
As background it is essential to understand a bit about consciousness and coma, for not all comas are created equally. In order to be conscious a person requires at least one hemisphere of the brain be mostly functioning and they require a functioning brainstem. The cortical hemispheres contain the gray matter – that part of the brain that thinks. So it makes sense that a certain minimal amount of gray matter is necessary to generate consciousness. As gray matter is damaged or inhibited from functioning one’s level of consciousness decreases until it descends beyond that fuzzy boundary into unconsciousness. When such unconsciousness is persistent we call that coma.
But interestingly the cortex by itself cannot generate consciousness. It requires constant prodding by a diffuse region in the brainstem (that primitive part at the base of the brain that connects the brain and the spinal cord) called the brainstem activating system. This region sends a constant barrage of electrical signals through the thalamus (the relay center of the brain) and then onto the cortex. Without this constant stimulation the cortex will lapse into sleep and coma.
On July 9th we held our first Science Based Medicine conference in Las Vegas. The event was definitely a success – we filled our room to capacity (150 attendees) and almost everyone stayed until the end. It also appeared that most attendees were actually awake, a rarity for a full-day medical conference. The Q&A session at the end was lively and interesting.
Kimball Atwood and I covered the history of science-based medicine and explored the differences between EBM and SBM. David Gorski discussed cancer quackery, including specific cases to illustrate the potential harm of pursuing worthless therapies for serious diseases. Harriet Hall gave us an overview of the the pseudoscience endemic in chiropractic. Mark Crislip discussed the chronic Lyme disease controversy. And Val Jones discussed health information online.
Based upon the feedback from those attending the conference, as well as the general enthusiasm, it seems that there is a hunger for this type of information. The audience was split about even between health care professionals and interested lay public. Many people asked if we plan on giving the conference again, and the answer is definitely yes. We have no plans set as of yet, and will certainly announce any future conferences here.
Simon Singh is a science journalist who last year wrote an article in the Guardian critical of the British Chiropractic Association (BCA) for promoting chiropractic treatment for certain childhood ailments. Singh characterized these treatments as “bogus” because they lack evidence to back up claims for clinical efficacy. The BCA responded by suing Singh for libel. In the English court system the person being sued for libel is essentially guilty until proven innocent, and even successfully defending oneself can be ruinously expensive. Therefore suing for libel in English court is a very successful strategy for silencing critics.
This case resulted in a bit of a backlash against the BCA, who were accused of silencing legitimate and very necessary public scientific debate regarding the safety and efficacy of medical interventions. The BCA could have simply responded by providing evidence to back up their claims, and the Guardian even offered them space to do so, but instead they sued.
Part of this backlash is a movement, supported by many scientific organizations, to keep libel laws out of science.
Last week I reviewed the history of chiropractic and discussed issues relating to its underlying claims and treatments for non-musculoskeletal indications. Today I will focus on chiropractic for back pain and similar indications.
There is evidence to support the very narrow indication of spinal manipulation for the symptomatic management of acute uncomplicated lower back strain. The good news for chiropractors is that this is a very common condition and does not respond well to conventional management – actually all treatments: medical management, physical therapy, manipulation, and even just patient education, appear to be equally and quite modestly effective.
There is a body of clinical studies that are relevant to the question of manipulation for lower back strain. A review of this research was published in 1989 by the RAND corporation, an independent research group that put together a panel of both physicians and chiropractors to review the available research on manipulative therapy. They concluded that evidence from 22 studies supported the use of manipulative therapy for acute uncomplicated lower back pain (again – no real pinched nerves). It is important to understand, however, that they were referring to manipulative therapy, not chiropractic. In fact only 4 of the 22 studies mentioned included chiropractors. In the other studies the manipulative therapy was performed by physicians and physical therapists.
When patients ask me if a chiropractor can help them with their problem, I often think to myself, “OK, do I give them the short answer or the long answer?” The difficulty is often in the fact that chiropractic is a diverse profession and it is difficult to even characterize what a “typical” chiropractor is likely to do. As a chiropractor once admitted to me – there are a great many things that happen under the umbrella of “chiropractic.”
In this article I will summarize some of the history and practice of chiropractic, highlighting what I consider to be many of the enduring problems with this profession.
Chiropractic was founded in 1895 by Daniel David Palmer, a grocer with an intense interest in metaphysics. Prior to his “discovery” of chiropractic, D.D. Palmer was a magnetic healer. He also had interests in phrenology (diagnosing disease based on the bumps of the skull) and spiritualism. Palmer reported to have discovered the principle of chiropractic when he allegedly cured a janitor of his deafness by manipulating his neck. The fact that the nerve which conveys sound information from the ears to the brain does not pass through the neck did not seem to bother Palmer, if he was even aware of this fact.
Palmer created the term “chiropractic,” which literally means “done by hand,” to refer to his new therapy. He argued that all disease is caused by subluxated bones, which 95% of the time are spinal bones, and which disrupt the flow of innate intelligence. He did not subject his ideas to any form of research, but rather went directly to treating patients and to teaching his principles to the first generation of chiropractors.
On June 16th the FDA issued a warning advising consumers not to use Zicam Nasal Gel or Nasal Swabs because of reports that it can damage the sense of smell, a condition called anosmia. This event highlights some problems with current regulations of health products.
There have been 130 cases reported to the FDA of decreased sense of smell following the use of one of these Zicam products – sometimes after a single use, sometimes after repeated use. All of these cases were reported by patients or their doctors; none were reported by the company, Matrixx Initiatives. According to reports, the FDA has asked Matrixx to turn over 800 consumer complaints regarding to Zicam. There is a 2007 law that requires company to report such complaints to the FDA, although the FDA has not said whether Matrixx violated this law.
Anosmia is a serious medical condition. The senses of smell is one of those things we take for granted until it is gone. People who lack a sense of smell cannot tell if milk has gone sour or if their food is bad. They cannot smell smoke to warn of a fire, nor can they smell a gas leak. The FDA fears that some of the cases of anosmia associated with Zicam use may be permanent.
The tick borne spirochete infection known as Lyme disease was named after Lyme, CT – a part of the country where the disease remains endemic. It is therefore especially poignant that the Connecticut state senate unanimously passed Public Act No. 09-128: AN ACT CONCERNING THE USE OF LONG-TERM ANTIBIOTICS FOR THE TREATMENT OF LYME DISEASE.The bill had previously passed the state House, also unanimously.
This is a terrible bill that is both anti-science and anti-consumer protection. How it passed both houses without dissent reflects exactly why such micro-management decisions should not be made by politicians. It is the result of lobbying by a narrow interest group and does not reflect either the state of the science on Lyme disease nor the proper role of regulation to ensure standards of care within medicine.
This is also not an isolated case. There is already a similar law in Rhode Island, and there have been similar bills proposed in Pennsylvania, Massachusetts, and New York, and a bill in Maryland that would compel insurance companies to pay for antibiotic treatment for chronic Lyme disease CLD. This is part of a coordinated effort by individuals and organizations who hold an ideological opinion regarding the cause and treatment of CLD. They wish to use the political process to win a victory for their view that they have been unable to win in the arena of science (sound familiar).
The bill now awaits Governor Rell’s signature, which given the heavy political support for this bill seems almost certain.
This bill represents much which is wrong with the state of science and medicine in the US.
In the US children must have proof of vaccination before entering the public school system, although it is becoming easier in many states for parents to gain exemptions from this requirement. In the UK there is no such requirement. This distinction has allowed for a comparison of the impact of scaremongering about the safety of vaccines and the effectiveness of campaigns to improve vaccination rates.
In the UK the scare that the MMR vaccine may be connected to autism (it isn’t) triggered by the bogus study by Andrew Wakefield resulted in a precipitous drop in vaccination rates down to about 78% overall. This is far below what is necessary for herd immunity, when immunity is prevalent enough to prevent a disease from spreading around a population. And the 78% figure is an average – but there are pockets where the number is even lower. This resulted in a surge of measles – from a low of less than 100 cases per year to 1,348 cases in 2008. The surge contniues despite an aggressive campaign to inform the public about the safety of the MMR vaccine.
By contrast the US has seen continued high overall vaccination rates of about 90%. The MMR and other vaccine scare came to the US a bit later than the UK but it is in full swing here, without much effect on overall vaccination rates. However, we are beginning to see the emergence of low vaccination rates in specific communities, with subsequent outbreaks of measles (131 cases in 2008), mumps, and whooping cough.
The Centers for Disease Control (CDC) currently recommends that children 6 month to 18 years old receive an annual flu vaccine. There are two types of flu vaccines used in the US: a live attenuated virus (LAIV) and a trivalent inactivated virus (TIV) vaccine. Both are safe and effective – while efficacy varies from year to year, they are 70-90% effective in healthy adults. Efficacy is young children appears to be slightly less, about 66%.
There remains, however, many sub-questions about the flu vaccines and by the time researchers have thoroughly explored them vaccine technology is likely to have progressed, and therefore any new vaccines will have to be tested all over again.
One of those sub-questions about vaccine safety and efficacy is the net effect of the flu vaccine in children with asthma. Some have raised concerns that the vaccine may exacerbate asthma, a 1-2% increased wheezing and 3% increased hospitalizations have been reported, although so far the bulk of the data suggests that both types of flu vaccines are safe in children with asthma. There is evidence to suggest that the LAIV may be superior to the TIV in children, particularly with asthma.
Last week I discussed a clinical trial comparing standardized acupuncture, individualized acupuncture, placebo-acupuncture, and usual care. In that discussion I emphasized the comparison between the three acupuncture groups, which did not show any difference in outcome. These results are consistent with the overall acupuncture literature, which shows in the better controlled trials that it does not matter where you stick the needles or even if you stick them through the skin. Therefore the scientific evidence fails to reject the null hypothesis (that acupuncture does not work). This did not stop the press from declaring, almost uniformly, that acupuncture works for back pain, contributing to the public misunderstanding of clinical science.
This week I am going to focus on the other aspect of the trial – the one the researchers and the press chose to focus on – the comparison of the two real and one placebo acupuncture arms to “usual care.” This too was misrepresented by the press, encouraged by the overinterpretation of the evidence by the researchers.
In the comments to Part I of this discussion David Gorski correctly pointed out that the study in fact did not even constitute a comparison of acupuncture to standard medical treatment. He is absolutely correct, and the many reasons for this are worth explaining in detail. Understanding the technology of clinical trials is central to science-based medicine, including all of their pitfalls and limitations. For practical and logistical reasons there is almost never a perfect clinical trial, but mischief only ensues when limitations are not understood, leading to a misinterpretation (and almost always an overinterpretation in the direction of the researcher’s bias) of the evidence.