Sunday, December 05, 2010

Autism Brain Scan Tests or Just High Functioning Autism Brain Scan Tests?

MSNBC has an article by Amanda Chan on the recent "autism" brain scans Brain scan 'best thing so far' for detecting autism. The article  cautions that the fMRI tests used in a recent study have to be run many times and achieve similar results before the test can be put to clinical  use. The article also does point out that the "autism" subjects in the test were all persons with high functioning autism.  Notwithstanding the cautions expressed the article still  refers to the test results in terms of detecting autism with substantial accuracy  not just high functioning autism.  Given the large numbers of persons with Autistic Disorder who have intellectual disabilities  references to high functioning autistic persons as being representative of autism generally are inaccurate and potentially misleading.

In Study: More Hope for a Brain Scan for Autism Meredith Melnick of TIME also reports on the recent brain scan studies and the same pattern emerges. The use of high functioning autistic subjects only is noted and cautions expressed about the need for more tests.  But once again the article indicates that the study results were able to detect "autism" in a large,  93%, of cases. There is even a reference in the article to "the autistic brain" when describing the results of a recent London MRI study which found that "the test was able to identify the autistic brain with about 90% accuracy."

Influential media sources like MSNBC and TIME are creating a popular view of "autism" as being represented by "high functioning autism".  They are doing so based on a string of research studies which use high functioning autistic subjects and exclude those with low functioning autism. The cautions expressed in such articles are likely to be forgotten as more and more studies of high functioning autistic subjects publish their reports and the excitement builds that a reliable brain scan test has arrived.

Autism disorders are neurological disorders.  Whether and to what extent various genetic and environmental considerations come in to play are matters of great contention. But to my knowledge no one except a few ignorant, cynical comics dispute that autism disorders are neurologically based.  Brain scans do in fact appear to be promising as tests that could distinguish "autism" neurology from others and thereby provide a reliable biologically based diagnostic tool. But only if study participants from all points on the autism spectrum are considered.

Unless low functioning and intellectually disabled subjects are included in the studies used to develop autism brain scan tests such tests could only in honesty be used to detect high functioning autism and could not rule out low functioning autism in any given case.

We should not lose sight of these fundamental truths when developing "autism" brain scan tests.


Larry Arnold PhD FRSA said...

I have a glimmer of hope here, that maybe we do agree on something that not everything that is announced about so called science is accurate or truthful.

I think because the tools are there, that we will see yet another set of mutually incompatible conclusions drawn by different research institutes.

And do you know why?

They are intellectually lazy!

Jake Crosby said...

I would think if they could detect the more subtle abnormalities in high-functioning autism, that they'd be able to pick up the more severe end of the spectrum, too.

Unknown said...

Interesting point Jake but it is an assumption. We don't actually know if all instances of autism disorders, particularly low vs high functioning, result from the same neurological profiles. The scans could just as conceivably result in exclusion of low functioning autistic persons because of different neurological profiles. We won't know unless brain scan studies include participants from other points on the spectrum which assumptions hold up.