Archive for August, 2010

Aug 31 2010

Using Traditional Healers to Treat AIDS in Africa

There is an AIDS epidemic in Africa, and efforts to fight it are hampered by the endemic social problems of that continent. Chief among them are the lack of sufficient modern health resources, the spread of destructive rumors and myths about HIV/AIDS, and even the persistence of HIV denial in Africa (although this last factor is better than in the past).

The World Health Organization (WHO) and the International HIV/AIDS Alliance are teaming up with the Traditional Health Practitioners Association of Zambia (THPAZ) to address the first problem – the lack of health services. Most Zambians use traditional healers for primary health care. The WHO has therefore decided to utilize traditional healers in the fight against AIDS. There are interesting pros and cons to this policy, but it must first be recognized that there is no ideal solution to the problem. The resources to provide optimal modern health care to treat and prevent HIV/AIDS (which would need to include a massive education program) in Zambia and the rest of Africa simply do not exist. One might argue that the world should provide those resources, but let’s put that issue aside and focus on what to do in the meantime.

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Aug 30 2010

Did One or Two Impacts Kill the Dinosaurs?

Published by under General Science

Note: Late post today. I am covering the in-patient service and more time constrained than usual.

By now most people know that the dinosaurs (now clarified as non-avian dinosaurs), along with 85% of species alive at the time, became extinct 65.5 million years ago as a result of a massive meteor impact. This is almost certainly the impact crater at Chicxulub, which dates to the correct time. In addition, examination of fossils and geological layers centers this extinction event at Chicxulub.

This is referred to at the K-T extinction, referring to the end of the Cretaceous and beginning of the Tertiary periods. However, use of the designation “Tertiary” is being phased out, and the K-T extinction is now being referred to as the K-Pg extinction – for Cretaceous-Paleogene.

While the single impact theory is the current consensus, there are two significant if minority competing theories. One is the Deccan Traps flood basalts – a 200 thousand year long event spanning the K-Pg boundary that involved massive volcanic eruptions, which could have causes extinctions through release of dust and sulfuric aerosols into the atmosphere. While not dead, this hypothesis has not fared well under recent evidence and is supported by only a small minority of paleontologists.

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Aug 27 2010

Doctor’s Faith and End of Life Decisions

A new study published in the Journal of Medical Ethics reports on a survey of various characteristics of physicians – specialty, ethnicity, and religious faith – and the way they deal with end of life care. According to these results, ethnicity had little to no effect. The specialty of the practitioner has the greatest effect, with hospital-based doctors discussing and using methods that may hasten death in the terminally ill at 10 times the rate of palliative care specialists. But the most widely reported result is that doctors who are agnostic or atheist were twice as likely to use such methods as deeply religious doctors.

As with most such studies, the two types of questions to ask are – are the results reliable, and if they are reliable what do they mean. To the first point, this is a very weak study. First, it is a self-reporting survey. This is the weakest kind of survey, because it is not strictly scientific – there is a huge effect from self-selection bias. The surveys, in other words, may mostly reflect who is willing to answer the survey, which can overwhelm other factors.

In this survey 8,000 doctors were contacted, and less than four thousand responded. That right there is a massive self-selection factor that renders any results of this survey preliminary at best. Such a survey can be used to generate hypotheses to be confirmed, but not something upon which specific recommendations should be based. Regardless, the authors do just that, recommending:

Greater acknowledgement of the relationship of doctors’ values with clinical decision-making is advocated.

Rather the authors should have concluded: Further testing of the possible relationship between specialty, religious belief, and decision-making is warranted.

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Aug 26 2010

Foreign Accent Syndrome

Published by under Neuroscience

Via YouTube, we can see another case of “foreign accent syndrome (FAS).” This is a rare condition in which a person appears to speak with a foreign accent following a stroke or other brain damage. In this case a woman from Devon who naturally speaks with a “west country lilt” now is said to speak with a Chinese accent. Take a look at the video and decide for yourself.

Essentially this woman has had a migraine stroke – which is the most common cause of stroke in in younger adults. This may have damaged either her language area (specifically Broca’s area or a nearby region that would affect Broca’s function, causing a form of aphasia) or it is also possible that she has damage in another part of the brain causing weakness of certain muscles involved in speech, in which case we would term what she has a dysarthria. I think the former is more likely just from how she sounds, but cannot say definitively without more information.

In any case, the damage has altered her speech, making it more difficult for her to pronounce certain words and also appears to affect the prosody of her speech – her inflection and rhythm. The result is only vaguely reminiscent of a Chinese accent, in my opinion. And you can still hear a bit of her native accent underneath. This is actually an excellent example of what foreign accent syndrome is (as the expert on the video correctly points out) – it is just a coincidence and a heavy helping of pattern recognition that the resulting speech abnormality reminds us of one of the many accents in the world – in this case, Chinese.

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Aug 24 2010

Fake Diagnosis Fatigue

There is yet another dubious diagnosis coming into vogue – adrenal fatigue. This is an entirely made up syndrome invented by naturopath and chiropractor James Wilson. His website begins with the classic solicitation:

Are You Experiencing Adrenal Fatigue?*

* Tired for no reason?
* Having trouble getting up in the morning?
* Need coffee, colas, salty or sweet snacks to keep going?
* Feeling run down and stressed?

If you answered “yes” to one or more of these questions, you may be experiencing adrenal fatigue.*

That’s right – even if you answered “yes” to just one of those questions, which means that you are an average adult, then you may have this fake syndrome. This is beyond satire.

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Aug 23 2010

Kurzweil vs Myer on Brain Complexity

Published by under Neuroscience

There is an interesting blog debate going on between PZ Myers and Ray Kurzweil about the complexity of the brain – a topic that I too blog about and so I thought I would offer my thoughts. The “debate” started with a talk by Kurzweil at the Singularity Summit, a press summary of which prompted this response from PZ Myers. Kurzweil then responded here, and Myers responded to his response here.

Futurism

You can read the exchange for all the details. I want to focus on just a couple of points – predicting our efforts to reverse engineer the brain, and the question of how complex the brain is.  Kurzweil has predicted in the past that we will reverse engineer the brain – model its function in a computer, basically – by 2030. It was reported that in his talk he said 2020, but Kurzweil has clarified that this is not correct, he said 2030, sticking to his earlier predictions.

That’s a minor (but interesting) point, and Myers points out that it was not the focus of his original criticism. I agree with Kurzweil on some basic principles. First, we do have an active research program that is using computer modeling to reverse engineer the brain. These efforts are progressing nicely, and I do think that eventually they will succeed. I also agree that some technologies progress at an exponential rate, and they surprise those who were making predictions based upon a linear progression. Kurzweil gives an excellent example of this – the genome project. This project started out very slow, and many thought it was lagging behind predictions, but as technology improved the effort to decode the human genome accelerated geometrically and actually finished years ahead of schedule. Now we can decode the genome of other species in a fraction of the time, and the pace continues to accelerate.

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Aug 20 2010

More Evidence that Acupuncture is a Placebo

I have written numerous blogs both here and on SBM about the acupuncture literature, which clearly shows that acupuncture, for any indication, is nothing but an elaborate placebo. Rigorous studies of acupuncture that actually try to isolate variables have shown that it does not matter where you stick the needles or even if you stick the needles – those variable do not have any specific effect. Acupuncture points and meridians are an illusion – nothing but superstition.

But there does appear to be a significant placebo effect, in addition to non-specific effects from relaxation and therapeutic attention, to the ritual of acupuncture. Does this mean “fake acupuncture works?” No – it means acupuncture does not work, but there are known placebo effects from the process of getting treated.

Now we have yet another study that supports the conclusion that acupuncture is just a placebo – but with an added element that is very interesting. Researchers compared traditional Chinese acupuncture (TCA) with sham acupuncture (non acupuncture points, shallow needle insertion) and another control group with no treatment for knee osteoarthritis. The researchers also did one very interesting thing, and one very sloppy and annoying thing (in my opinion). The sloppy thing was to use “electroacupunture” – which isn’t pure acupuncture. It’s acupuncture plus transcutaneous electrical nerve stimulation, which is an already proven modality for pain. In the TCA group they gave full “electroacupuncture” and in the sham group they gave less stimulation – enough to serve as an active placebo but not enough to have any effect.

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Aug 19 2010

Alzheimer’s and Diet

The pattern is depressingly common – take a disease that is not currently cured by science-based medicine. Claim that doctors “don’t care”, or are ignoring treatments that do not make them money, or there is a conspiracy of silence headed by “Big Pharma.” Then offer a snake-oil alternative based upon anecdotal evidence. Sometimes faith and God are thrown in for good measure.

Nita Scoggan fits this mold nicely. She is promoting herself as a “health and happiness coach” and using her husband as anecdotal evidence of the power of her nutritional advice. The story is now being promoted by other low-carb gurus, including Jimmy Moore.

The story is a great example of why anecdotes are so problematic. We are told that Nita’s husband, Bill, was diagnosed with Alzheimer’s disease, but she cured him with diet and nutrition, specifically coconut oil and a low carb diet. The problems with this story begin with the diagnosis. Scientific medical trials always include what are called inclusionary and exclusionary criteria – this is to make sure that subjects actually have the disease that is being studied. This is critical because apparent remissions may be due to the fact that the person never had the alleged disease in the first place.

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Aug 17 2010

More On Autism Prevalence

Published by under autism

In order to teach science to the public it is better to tell a story about how questions are resolved in science, rather than simply to teach authoritatively the current findings of science. The process is interesting – often more so than the facts.

One such story is the true cause of the increasing autism prevalence over the last 20 years. There is no question that the number of people being diagnosed with autism is increasing. There are various theories as to why, the best, in my opinion, is that the increasing numbers are an artifact of broadening the diagnosis and increased surveillance. Meanwhile, a true increase may also be hiding in the numbers, and that would present an interesting (and important) mystery to solve.

I have written about this before (here and here on SBM, and again here on NeuroLogica). Now there is a new study which may shed some light on the question, but to quickly summarize where the evidence is: There are several ways to address the question of whether or not there is a true increase in autism numbers. One is to assess autism prevalence at various age groups. If true autism incidence is increasing, that younger age groups should have more diagnoses of autism than older age groups – when the same diagnostic criteria are applied. When this kind of analysis is done it appears that autism incidence is stable over time, which is powerful evidence against a true increase.

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Aug 16 2010

Banning Wi-Fi From Schools

In the town just north of where I live the middle school was completely torn down and an entirely new middle school was built. The reason for this was concerns that mold in the old school was making children sick.

Apparently, Wi-Fi is the new mold. In central Ontario parents are lobbying the school to turn off the Wi-Fi due to fears that it is making their children sick. You can take the news report of the parents concerns, time-warp about ten years in the past, and substitute “mold” for “Wi-Fi” – the arguments are the same, and the evidence as weak, but the identified problem has just shifted.

The Evidence

Let’s start by reviewing what we currently know about the health risks of Wi-Fi – wireless signals used to connect computers to a network or the internet. From a basic science perspective, there is little plausibility to the notion that Wi-Fi radiation would have any health effects. The amount of energy that is absorbed by a person living in a Wi-Fi field is negligible - less than 1% of exposure from a typical cell phone and well below current safety levels.

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