Thursday, August 26, 2010
As I mentioned in an earlier blog, I used to enjoy quail hunting. Flushing a covey that your dogs have pointed and having fried quail for breakfast was a real treat in the South where I live. But those days are gone. In Texas, where I'm from there are still quail, but the difference seems to be that in Texas there is ranch land and in the area of the South where I live it's farmland. Farmland means chemicals-pesticides-herbicides-fertilizer-etc. There are studies that show the closer you live to an agricultural field the higher the incidence of autism. I think there is a good chance that whatever killed the quail is also getting into our children either pre or post-natal. Humans are larger than quail so the unknown chemical culprits are not in high enough concentration to be fatal, but in high enough concentration to mess with the wiring of the brain. I was glad to see that more research into the environmental causes of autism was suggested to the Interagency Autism Coordinating Committee (IACC). Autism has a genetic component, but the concordance rate is low and other etiological factors have to be investigated. There is already some evidence to suggest that ADHD is related to environmental chemicals so the hypothesis seems reasonable.
Wednesday, August 18, 2010
The argument regarding the autism epidemic goes on. One side saying we are in the midst of an autism epidemic with 1 in 110 children being born ending up with an autism diagnosis. The other side saying changes in the diagnostic criteria for autism which resulted in a drop in the number of children diagnosed with mental retardation and learning disabilities explains the increase. A recent study by Peter Bearman at Columbia University in New York sheds some light on the controversy. He and his colleagues identified three variables, which account for much of the increase in the number of cases of autism. Diagnostic changes, parents being more aware of autism, and older parents. However, when they quantified these 3 variables to see what percentage of the increase they accounted for they found that these 3 variables only accounted for half of the increase in the number of autism cases. So it sounds like both sides are right--half right anyway.
Thursday, August 12, 2010
A class of drugs called selective serotonin reuptake inhibitors (SSRI's) are commonly used to treat autism in children as young as two. SSRI's are better known as antidepressants by their trade names--Prozac, Zoloft, Celexia, etc. Serotonin is a neural transmitter in the brain involved in a variety of functions and some studies have implicated low serotonin levels in the brains of children with autism. Serotonin is measured peripherally in the blood or urine and no one has proved that peripheral measures of serotonin correspond to serotonin levels in the brain. A recent study concludes that there is not clear evidence that the SSRI's help children with autism. And I believe that when you look at the group statistics that is true. In our clinic many of the children with autism are prescribed SSRI's at some point. In some children I see no improvement. But in others, usually the younger children with poor muscle tone I see significant improvement so I think a trial is warranted.
Friday, August 06, 2010
Autism is 4-5 times more common in males than females. This observation led Simon Baron-Cohen to suggest that autism is caused by an extreme “male brain” which is in turn is caused by exposure to high levels of testosterone in utero. Research has shown that both males and females exposed to high levels of testosterone in the womb develop behaviors characteristic of autism. In my opinion, this is the best theory of autism that we have to date. In thinking about studies to test this theory I thought of a study that would test this theory, but was potentially harmful and could not be done. Then, this week to my surprise I read that if was being done--sort of anyway. Lupron is cancer drug, which blocks the body from making testosterone. Taking advantage of desperate parents, a group of doctors in South Florida are giving the drug to children with autism. But this is not a test of the extreme male brain theory. This is an attempt to remove mercury from the body, which is "believed" by some to be the cause of autism. There's no evidence that the Lupron removes mercury or that mercury is excessive in children with autism. Futhermore, there are significant health risk in giving Lupron treatments, which cost around $5000 a month, to children.
Tuesday, August 03, 2010
A recent large-scale study published online in Pediatrics reports that children with autism are "slow feeders" at 6 months and at 15 months are finicky eaters compared to normally developing children. However, these feeding problems do not appear to affect growth or energy levels. The authors suggest that feeding problems may be early diagnostic signs of autism so clinicians should ask about feeding problems. I think this is a good idea, but maybe the finicky eating has nothing to do with food. In my clinic I often note that children with autism are finicky eaters at all ages. But I think this could be because children with autism are just as likely to reject food on the basis of texture as taste and I also know that children with autism do not like change and characteristically follow rigid routines. I've seen cases where a rigid diet would be followed for years and I don't think it had anything to do with food, but simply routine. I know of one adult with autism who had eaten the same exact lunch, a peanut butter and jelly sandwich, for 20 years and on the few occasions when some other food was given to him he had tantrums. He would eat the other foods that were offered to him just not at lunch.