Wednesday, July 28, 2010

More autism scare tactics

So apparently someone got bored of the vaccines cause autism nonsense, and decided a new brand of nonsense was needed to keep new and future parents afraid of advanced medical technology.  His name is Dr. Manuel Casanova:
Dr. Manuel Casanova believes something very common to all pregnant women may be contributing to the growing number of autism cases.
Nearly every pregnant woman gets an ultrasound - or two or three.
These days, parents post the pictures on websites; everything from YouTube, where you’ll find images of babies in-utero with background music, to their own personal blogsites.
In ultrasounds, high frequency sound waves get images of the baby, measurements are taken, abnormalities detected, and the sex of the baby is learned
Now, though, Dr. Manuel Casanova, a noted research scientist at the University of Louisville, is sounding a warning about ultrasounds.
“It's not just about taking a picture of your baby,” he said.  “This has physical and chemical effects and it's poorly regulated by the government.”
Casanova published a report earlier this year in the journal “Medical Hypothesis,” spelling out his concerns of ultrasounds.
OK, so ultrasounds are more common than in the past, and diagnosis of autism is more common than in the past.  Therefore, ultrasounds cause autism.  Anyone else see the problem with this reasoning?

But I'll bite, what other evidence does he have?  The article is useless, but that doesn't mean anything.  Science reporting is almost always poor, without presenting anything useful from the original publications.  Unfortunately, I can't get to the full original article by Dr. Casanova (and no other links found on Google Scholar).  But here is the abstract:
The phenotypic expression of autism, according to the Triple Hit Hypothesis, is determined by three factors: a developmental time window of vulnerability, genetic susceptibility, and environmental stressors. In utero exposure to thalidomide, valproic acid, and maternal infections are examples of some of the teratogenic agents which increase the risk of developing autism and define a time window of vulnerability. An additional stressor to genetically susceptible individuals during this time window of vulnerability may be prenatal ultrasound. Ultrasound enhances the genesis and differentiation of progenitor cells by activating the nitric oxide (NO) pathway and related neurotrophins. The effects of this pathway activation, however, are determined by the stage of development of the target cells, local concentrations of NO, and the position of nuclei (basal versus apical), causing consequent proliferation at some stages while driving differentiation and migration at others. Ill-timed activation or overactivation of this pathway by ultrasound may extend proliferation, increasing total cell number, and/or may trigger precipitous migration, causing maldistribution of neurons amongst cortical lamina, ganglia, white matter, and germinal zones. The rising rates of autism coincident with the increased use of ultrasound in obstetrics and its teratogenic/toxic effects on the CNS demand further research regarding a putative correlation. 
I don't know enough about NO pathways and the suggested effects to know how good his reasoning is in this summary.  If any biologist/med students reading know about this stuff, I'd love to hear about it in the comments.  Also, if anyone has access to the article, I'd be very interested in reading it.  (I'm going to try accessing the article when I'm at work tomorrow; I can sometimes get access to articles on Northeastern's wireless service that I don't have at home, but I don't expect this journal to be accessible.  If I do, I'll amend this post, or create a new one.)

But even if he is right on about NO pathways, the number of assumptions made from NO activation to autism here suggests to me there's a lot of conjecture that needs to be baked up by evidence.  The ending of the summary simply states that rising autism rates coincide with increased use of ultrasound, with no mention of testing all of these connections in the reasoning chain, suggesting he doesn't address them in the paper (or its a poor summary of what research was actually done, which is what I expect to see in an abstract/summary).

Given that, I tentatively suspect that the news article is unnecessarily puffing up a very preliminary idea as something we really need to fear.  In addition, it appears that Dr. Casanova may not be very objective:
Dr. Casanova admitted autism is not just a professional pursuit.  For him, it's also a personal matter.  His grandson is autistic.
 Bertrand is Dr. Casanova's first grandchild.  Until he was 18-months-old, Bertrand played, babbled, and developed normally.
Then, he was diagnosed with Retts Syndrome, a rare form of autism in which the development regresses.
Dr. Casanova began to sound his warning about ultrasounds after seeing photos of Bertrand at his daughter’s house.
“She had in her coffee table a book that summarizes my grandson's first year of life,” he said. “For every year we have pictures.  The first picture, first page of that the first year of life, do you know what was his first picture?  Ultrasound.”
Dr. Casanova is a scientist who relies on years of painstaking research to draw conclusions, but this time, he’s raising his concerns early .
“My daughter, when I told her about ultrasound, she told me ‘Why, Daddy, why didn't you tell me you always suspected it could be a risk factor?  Why didn't you tell me?’” he said. “ I said, we have to be cautious. Right now maybe that has colored my perspective, and I’m not that cautious, but I know if I can prevent this even in one patient, I will have made my life's work.”
OK, now I'm much more confident in my assessment.  "But this time, he's raising his concerns early?"  How can anyone take this seriously?  He sees an ultrasound of his grandson, and concludes that must be what did it.  You'd think a scientist would be able to separate personal, emotional responses from his research.  Or if he can't, at least be aware that his personal experience may be clouding his judgment and be more cautious about drawing conclusions.

This sensationalist article isn't a surprise:  it seems to be popular for the news media to encourage people to fear everything about our modern society.  I hope this doesn't result in fear of ultrasounds and other important medical procedures, as the anti-vaccine movement has done for vaccinating children.
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