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The FDA and Personalized Genetic Testing

The company 23andMe provides personal genetic testing from a convenient home saliva sample kit. Their home page indicates that their $99 genetic screening will provide reports on 240+ health conditions in addition to giving you information on your genetic lineage. The benefits, they claim, are that you will learn about your carrier status and therefore the risk of passing on genetic diseases to your children. The information will also inform you about health risks so that you can change your behavior to manage them. Finally the genetic information will tell you about how you might respond to different drugs so that you can “arm your doctor with information.”

The home page also contains a link to testimonials about how their DNA testing has changed people’s lives.

This all sounds great – the promise of genomics that we have been hearing about now for about two decades. Isn’t this exactly what we were led to expect once we mapped the human genome?

Why, then, has the FDA recently sent a warning letter to 23andMe instructing them to discontinue marketing their Personal Genome Service (PGS)?

The primary reason appears to be a lack of documentation for the validity and reliability of the tests, but I have concerns that go even deeper. (more…)

Posted in: Public Health

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The Nuances of Informed Consent

Modern medical ethics are built upon the concept of informed consent. This is not, however, as straightforward a concept as it may seem.

Physicians and health care providers have a duty to provide informed consent to their patients or their patients’ guardians, which means that they have to inform them appropriately about the risks and benefits of their recommendations and interventions. This includes informing them about the risks of not treating an illness.

This principle is, in turn, based largely upon the principle of autonomy – people have the right to control their own lives, and one cannot have control without information.

This is all simple enough, but where it becomes tricky is in deciding how much information to give patients, and how to present it. (more…)

Posted in: Critical Thinking, Medical Ethics, Science and Medicine

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Detecting Consciousness in the Vegetative

People in a vegetative state, usually as a result of brain trauma or anoxia (lack of oxygen) by definition have no signs of conscious awareness or activity. The definition, therefore, is based largely on the absence of evidence for consciousness.

Of course, arguments based upon the absence of evidence are only as compelling as the degree to which evidence has been properly searched for. In recent years technology has advanced to the point that our ability to detect the possible subtle signs of consciousness in those presumed to be vegetative has increased – mainly through functional MRI scans (fMRI) and electroencephalograms (EEGs).

There has been a steady stream of studies demonstrating that a small minority of patients thought to be vegetative actually display some signs of minimal consciousness. The latest such study was recently published in Neuroimage: Clinical by a research team from the University of Cambridge.

But let’s back up a bit first. Even prior to evaluating vegetative patients with fMRI and advanced EEG techniques, several studies showed that a detailed neurological exam specifically designed to detect the most subtle clinical signs of consciousness could find such signs in some patients who were diagnosed as being vegetative by more standard neurological exam. According to one study as many as 41% of patients diagnosed as vegetative were really minimally conscious, meaning they had subtle signs of consciousness, but still cannot wake up, converse, or act purposefully. (more…)

Posted in: Neuroscience/Mental Health

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Lorenzo’s Oil

Augusto Odone is an Italian economist best known for his son, Lorenzo, after which Odone named the oil that he helped develop to treat his son’s neurological disease. Lorenzo’s oil was the subject of a 1992 movie starring Nick Nolte and Susan Sarandon, and of course what most people think they know about the story they learned from the Hollywood version.

This past week Augusto Odone died at the age of 80, prompting another round of media reporting about Lorenzo’s oil.

Probably because of the Hollywood movie, this story more than any other is an iconic example of the disconnect between the simple narratives the media love to tell (and we love to tell ourselves) and the more complex reality.

The basic facts of the story are not in dispute. Lorenzo Odone, son of Augusto and his wife, had a neurological disease known as X-linked adrenoleukodystrophy (X-ALD). This is a devastating genetic disease in males, with two basic forms. Childhood onset tends to progress rapidly and typically death occurs by age 10, although lifespan can be increased if an early bone marrow transplant is given. In adult onset, symptoms may not appear until adulthood, and then tends to progress more slowly, over decades. Some boys with the X-ALD gene do not develop clinical findings. Women are carriers, with partial protection from their second X chromosome. About half of female carriers become symptomatic, with the slower adult form of the disease.

(more…)

Posted in: Neuroscience/Mental Health, Science and Medicine

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The CAM Worldview

Harriet has written some excellent recent posts about how to talk to CAM (complementary and alternative medicine) proponents, and answers to common CAM fallacies. I have written about this myself numerous times – we deal with the same logically-challenged claims so often that it’s useful to publish standard responses.

In fact, I often wonder about the seeming uniformity of poor arguments put forward by advocates of CAM and critics of SBM. Do their arguments represent common problems of thought, pathways of mental least resistance, or are we seeing the repetition of arguments resonating in the echochamber of a subculture? I suspect it’s all of those things, which all feed into a particular world-view.

Actually CAM proponents seem to fall into one of several common world views, or flavors, as I like to call them, ranging across the spectrum from pseudoscience to anti-science. There is substantial overlap, however, with common anti-scientific themes.

I recently had an exchange with an SBM reader who was demanding that a particular post be taken down, because “every single fact in the article is wrong.” I responded as I always do – please point out the factual errors, with proper references, and I will make sure that all appropriate corrections are made. This did not satisfy the e-mailer who insisted that the article was 100% false and libelous.

(more…)

Posted in: Science and Medicine

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Monochloramines in Tap Water

I recently had a clogged drain requiring the services of a plumber. While discussing the details of the job, he took out brochures and a “fact sheet” prepared by his company explaining that my city tap water was going to kill me. Fortunately, they could provide a solution – a home-wide water filtration system.

The plumber seemed naively sincere, and genuinely fearful of the cancer-causing contaminants found in drinking water. He invited me to read through the material he provided while he unclogged by drain. I did better than that. I took the time to do a quick search for some more objective information on the topic.

Monochloramines

The focus of this particular scaremongering is the additive monochloramine, which is added to city water. According to the Environmental Protection Agency (EPA):

Chloramines are disinfectants used to treat drinking water. Chloramines are most commonly formed when ammonia is added to chlorine to treat drinking water. The typical purpose of chloramines is to provide longer-lasting water treatment as the water moves through pipes to consumers. This type of disinfection is known as secondary disinfection. Chloramines have been used by water utilities for almost 90 years, and their use is closely regulated. More than one in five Americans uses drinking water treated with chloramines. Water that contains chloramines and meets EPA regulatory standards is safe to use for drinking, cooking, bathing and other household uses.

(more…)

Posted in: Public Health, Science and Medicine

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The End for CCSVI

A new study published in The Lancet provides the most definitive evidence to date that chronic cerebrospinal venous insufficiency (CCSVI), a hypothetical syndrome of narrowed veins draining the brain that some believe is the true cause of multiple sclerosis (MS), is not associated with MS.

In a science-based world, this study would be yet one more nail in the coffin of this failed hypothesis. But that’s not the world we live in.

CCSVI background

CCSVI was first proposed in 2009 by Italian vascular surgeon, Dr. Paolo Zamboni – that multiple sclerosis (MS) is caused by chronic blockage of the veins that drain the brain. The current scientific consensus is that MS is a chronic autoimmune disease, and the pathology is caused by primary inflammation. Dr. Zamboni believes that the venous anomalies he has discovered are the primary cause and the inflammation is secondary. (more…)

Posted in: Neuroscience/Mental Health

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Chiropractor Breaks Baby’s Neck – A Risk vs Benefit Analysis

It is unfortunately that individual dramatic cases are often required to garner public and regulatory attention toward a clear problem. The Australian press is reporting:

Melbourne paediatrician Chris Pappas cared for a four-month-old baby last year after one of her vertebrae was fractured during a chiropractic treatment for torticollis – an abnormal neck position that is usually harmless. He said the infant was lucky to make a full recovery.

Medicine is a game of risk vs benefit – everything we do, or don’t do, should be evaluated on the potential benefit vs the potential risk, using the best available evidence and scientific rationale. This case is important, not because it is a case of harm, which can happen with any intervention, but because it highlights the risk vs benefit question. Are there any indications for chiropractic care of children, for neck manipulation at any age, and what are the risks?

For an overview of chiropractic see my prior summaries here and here. Overall the evidence suggests some benefit for manipulative therapy for acute uncomplicated lower back strain, but probably no better than physical therapy or even minimal intervention. The risks of chiropractic are not sufficiently studied, and other indications have not been established by adequate evidence. (more…)

Posted in: Chiropractic

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Candida and Fake Illnesses

Savvy consumers have learned over the years that the primary goal of marketing is to create demand for a product or service. This has risen to the point of inventing problems that do not really exist just to sell a product that addresses the fake problem. Who knew that my social status could be destroyed by spotty glassware.

Better yet, if you can make people worry about a nonexistent problem, something that they were not previously aware of and don’t understand, they might buy your solution just to relieve their worry.

This type of “artificial demand” marketing can be very insidious when it occurs with medical products and services. The pharmaceutical industry has been accused of generating artificial demand for some of their drugs. For example, osteopenia is a relative decrease in bone density, but not enough to qualify for osteoporosis. Osteopenia is not really a disease, or even necessarily a mild version of osteoporosis, although it is a risk factor. Merck, however, was happy to broaden the market for its drug for osteoporosis and argue that patients with osteopenia should be treated also, even though the evidence really did not support this.

Sometimes the accusations are flat-out wrong. GSK has been accused of inventing restless leg syndrome (RLS) to sell a failed Parkinson’s drug. In fact the drugs used for RLS are successful Parkinson’s drugs. Further, I found references to RLS in neurology texts going back over 50 years, and there were even older references although not using the same name.

(more…)

Posted in: Science and Medicine

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Quantum Neurology

As the resident neurologist on SBM, my ears always prick up when I come across a new neurology-based scam, and my colleagues often send such items my way. In addition the word “quantum” has become a standard marketing term of alt. med quackery. So how could I resist taking a bite out of “quantum neurology”?

One might think (if one were a completely naïve rube) that those claiming to practice quantum neurology have, through diligent research, discovered how certain quantum principles apply to nervous system function and disease, leading to new treatment modalities. On the other hand, a more savvy consumer of such health claims (such as regular readers of SBM) would likely suspect that quantum neurology will turn out to be the same-old mix of nonsense and snake oil in a shiny new package.

Let’s have a look.

(more…)

Posted in: Chiropractic, Neuroscience/Mental Health

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