Can a brain bleed cause Autism?

madrabbitwoman · May 13, 2011, 11:44am

I have a friend with a nice, reasonably sociable intelligent kid. He was born very premature and as a result he had some bleeding in his brain and now has some issues. He has also been diagnosed as having aspergers syndrome. She seems to equate the bleed on his brain with him being on the autism spectrum. Is she correct?

ramel · May 13, 2011, 2:43pm

Most evidence is pointing towards AS being caused by genetic factors.

Bridget_Burke · May 13, 2011, 2:53pm

io9 has a report on studies being discussed at the current International Meeting for Autism Research. Lots of interesting stuff & links to even more interesting stuff.

And one crucial bit of information from yesterday’s press conference: David Amaral of U.C. Davis says that changes in brain growth associated with regressive autism are observable as early as 4-6 months of age, long before any behavior changes show up. “Precocious” brain growth and larger head diameters in those early months are associated with regression. (Which means, among other things, that the MMR vaccine, which is administered at 12 months, can’t possibly be causing these cases.)

Researchers have been able to identify autistic children at younger and younger ages, thanks to new diagnostic guidelines, and one result is a huge MRI study of autistic children aged 12 to 40 months. Among other things, researcher Eric Courchesne found that connectivity between the temporal lobe and the limbic system (including the amygdala) is very different in austistics, from early on. And young autistics have twice the number of cells in their frontal cortex as other kids. Also, a measure of brain development called fractional anisotropy (FA) is much higher in young autistics than other kids, but then doesn’t grow as quickly as it does in normal children as they grow older…

Other research presented today suggested that a difficult labor or fever during the early part of pregnancy could help cause autism-spectrum disorder (ASD), and that mothers who have hypertension or diabetes, or are obese before pregnancy, may be more likely to have autistic children.

WhyNot · May 13, 2011, 3:00pm

It’s…complicated.

Yes, preemies have higher rates of autism. Micropreemies have higher rates of autism than older preemies. Preemies who have cerebral bleeds have higher rates of autism than preemies who don’t have bleeds.

But that doesn’t mean the bleed *caused *the autism. It may be that something else (genetics, gestational diabetes, perhaps even an infection in pregnancy) caused the autism *and *the brain bleed *and *the prematurity. We just don’t know.

On a practical note, I wouldn’t try to talk her out of it. Really, it doesn’t do much good at this point. The child now has autism, and we don’t treat autism after a brain bleed and differently than we do autism with no history of brain bleed. She needs, emotionally if not logically, something to ascribe this condition to, and a brain bleed is as good as any other reason, and a better one than most.