06-25-2006, 09:15 PM
Infants whose heads suddenly begin to grow rapidly appear to be at risk of autism, perhaps indicating the increasingly common disorder may be traced to missed connections in fast-expanding brains, researchers said.
The report also appeared to offer further proof that childhood vaccinations are not a cause of autism as some have suggested.
In a study involving 48 autistic subjects, 59 percent had accelerated skull growth -- and presumably brain expansion -- beginning around the age of 2 months and ending between four months and a year.
The study, published in this week Journal of the American Medical Association, found autistic children’s skulls went from being smaller than 75 percent of children to larger than 84 percent of them at the end of the growth spurt, wrote lead author Eric Courchesne of the University of California, San Diego, in La Jolla.
"This burst of overgrowth takes place in a brief period of time, between about two months and six to 14 months of age," Courchesne said. "So, we know it cannot be caused by events that occur later, such as vaccinations for mumps, measles and rubella or exposure to toxins during childhood."
Vaccinations and exposure to environmental poisons such as mercury have both been thought to be possible causes of autism. A study earlier this year pointed to a genetic component in some cases traced to chromosome 15.
The key question for researchers is whether rapid brain growth -- which in theory is too fast for vital neurological connections to form -- is the cause or just a symptom of autism. Autism is only diagnosed later, as early as age 2.
While the study was small it "is the first ... to our knowledge to find a potential early warning biological sign for autism and to link it to a later brain abnormality," Courchesne wrote. He agreed there is a need for a larger study.
U.S. autism cases tripled in the 1990s and it affects as many as six in 1,000 children, with four times as many boys as girls developing the condition.
Autism is defined by a wide range of symptoms. British scientists recently suggested Albert Einstein and Isaac Newton may have had mild forms after assessing their unsociable personalities; but it usually involves unusual social and emotional reactions and distancing from the environment.
From onlinenews.com
The report also appeared to offer further proof that childhood vaccinations are not a cause of autism as some have suggested.
In a study involving 48 autistic subjects, 59 percent had accelerated skull growth -- and presumably brain expansion -- beginning around the age of 2 months and ending between four months and a year.
The study, published in this week Journal of the American Medical Association, found autistic children’s skulls went from being smaller than 75 percent of children to larger than 84 percent of them at the end of the growth spurt, wrote lead author Eric Courchesne of the University of California, San Diego, in La Jolla.
"This burst of overgrowth takes place in a brief period of time, between about two months and six to 14 months of age," Courchesne said. "So, we know it cannot be caused by events that occur later, such as vaccinations for mumps, measles and rubella or exposure to toxins during childhood."
Vaccinations and exposure to environmental poisons such as mercury have both been thought to be possible causes of autism. A study earlier this year pointed to a genetic component in some cases traced to chromosome 15.
The key question for researchers is whether rapid brain growth -- which in theory is too fast for vital neurological connections to form -- is the cause or just a symptom of autism. Autism is only diagnosed later, as early as age 2.
While the study was small it "is the first ... to our knowledge to find a potential early warning biological sign for autism and to link it to a later brain abnormality," Courchesne wrote. He agreed there is a need for a larger study.
U.S. autism cases tripled in the 1990s and it affects as many as six in 1,000 children, with four times as many boys as girls developing the condition.
Autism is defined by a wide range of symptoms. British scientists recently suggested Albert Einstein and Isaac Newton may have had mild forms after assessing their unsociable personalities; but it usually involves unusual social and emotional reactions and distancing from the environment.
From onlinenews.com
) , always meant I was like 2 or 3 sizes bigger than everyone else for helmets and stuff in the scouts or horse riding.