January 20th, 2011
Autism: What’s the Truth??
Hollywood is known for a lot of things: celebrities, the “sign,” the Walk of Fame, and Rodeo Drive. However, Hollywood recently has started to make its name in another way. Between the 1988 film Rain Man and the recent ramblings of ex-Playmate Jenny McCarthy, this iconic location has become a hotbed of controversy about autistic disorders.
Autism, or more appropriately
Autism Spectrum Disorder (ASD), is “a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior.” Originally a condition that was diagnosed later in life, the numbers of newly diagnosed pediatric cases are rapidly increasing, most likely because of increased attention brought to it by the media. But the question that should be asked is whether the prevalence of autism is becoming more prevalent or are we just becoming more sensitive to it?
Jenny McCarthy is, without question, partly responsible for this new awareness. She has successfully redefined herself from Playboy pin-up to the face of autism in the media. Jenny has made it her mission in life to provide awareness of and support to autistic children. The motivation behind her undertaking is her son, Evan, who at the age of 2.5 years, was diagnosed with autism.
While on the Oprah Winfrey Show in 2007, she talked about the discovery of her son’s disorder and the trials of dealing with an autistic child. She detailed the horror that so many parents feel when facing their children’s first immunizations. Jenny recounts that even before her son received his vaccines, she tried to talk to her pediatrician about the risk.
“Right before his MMR shot, I said to the doctor, ‘I have a very bad feeling about this shot. This is the autism shot, isn’t it?’ And he said, ‘No, that is ridiculous. It is a mother’s desperate attempt to blame something,’ and he swore at me, and then the nurse gave [Evan] the shot,” she says. “And I remember thinking, ‘Oh, God, I hope he’s right.’ And soon thereafter — boom — the soul’s gone from his eyes…What number will it take for people just to start listening to what the mothers of children who have autism have been saying for years, which is, ‘We vaccinated our baby and something happened.'”
Subsequently, one of her platforms in discussing ASD is raising the alertness of vaccines and their perceived predilection to cause autism. This relationship originated from British physician Dr. Andrew Wakefield’s 1998 Lancet study that stated that the MMR vaccine directlycaused autistic disorders. According to the paper, Wakefield wrote, “We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers” — the possible triggers reported were the MMR vaccine in eight cases, and measles infection in one.
Further bringing attention to the association of vaccines and autistic disorders was the use of thimerosal as a preservative. Thimerosal is a mercury compound that is broken down to ethylmercury, which can be neurotoxic in high doses. This preservative has been used since the 1930s, but came under scrutiny when it was noted that as the incidence of autism was rising along with the use of thimerosal in vaccines. In July 1999, the FDA finally concluded that thimerosal be removed from all childhood vaccines because some children were receiving higher amounts of mercury than the established guidelines deemed to be safe. Currently, all childhood vaccines are thimerosal free, seemingly putting this aspect of the controversy to rest .
The other part of the controversy, the link between the MMR vaccine and ASD, should finally be settled as well. In the January 2011 issue of the British Medical Journal, an editorial was published by the BMJ editor, Fiona Godlee, that referred to Dr. Wakefield’s 1998 paper as an “elaborate fraud.” This comes after a reporter exposed that Wakefield and his colleagues altered the facts about their patients in the original study. Brian Deer, a British journalist, compared the patients’ diagnoses in the original paper to those in their hospital charts and found significant discrepancies. Whereas Wakefield stated that he found “gastrointestinal disease and developmental regression in a group of previously normal children,” this new analysis found that 5 of the 12 children had previously documented developmental problems.
Initially questioned because of its small sample size, the original conclusions never gained widespread medical acceptance because multiple repeat studies throughout the years continued to refute the findings. Now, convincingly, it can widely be accepted that vaccines are not directly related to ASD.
However, the coals have been burning too long on this fiery debate to simply cool off. On Jenny McCarthy’s website, it continues to say “We hope the media will take the time to read the actual Lancet study, rather than repeating the message of a vaccine-industry funded media circus… If all the science on vaccines and autism has been done, how come no one has yet looked at unvaccinated children?” The National Autism Association maintains on their website, “To date, studies conducted or funded by the CDC that purportedly dispute any correlation between autism and vaccine injury have been of poor design, under-powered, and fatally flawed. The CDC’s rush to support and promote such research is reflective of a philosophical conflict in looking fairly at emerging theories and clinical data related to adverse reactions from vaccinations.”
Just as one controversy quiets, another arises. To further confound the issue as to what causes autism, an article by Cheslack-Postava et al., published in the January 2011 issue of Pediatrics, the official journal for the American Academy of Pediatrics, reports the incidence of autism is threefold greater when siblings are born within 1 year of each other. It further states that siblings born 12 to 23 months after their first-born siblings have twice the risk, while siblings born 24 to 35 months after their first-born siblings are 26% more likely to develop autism than are their first-born siblings. This study was conducted retrospectively on 660,000 children born in California between 1992 and 2002.
So what are we to think? Do birth order and timing affect the likelihood of autism?
As far as science goes, due to the complexity of the disease process and its variable range of severity, no conclusive evidence tells us what causes autism. The working theory is that it is a condition that is influenced collectively by both genetics and environment. Researchers have located and identified several genes that might be associated with this condition but, again, data are inconclusive. Other studies suggest that it is caused by anatomic irregularities in the brain or to abnormal levels of neurotransmitters (e.g., serotonin).
Regardless, we can safely to say that the jury is still out. From a primary care perspective, we should be mindful of the perceptions that our patients have when it comes to autism and vaccines. Sometimes reassurance is all it takes, but often times, we are left with their decision not to vaccinate, even if it is against our own recommendations. And with this new study about the timing of pregnancies, who knows what the future holds.