Autism » Theories of the Etiology » Brain Trauma
Susan Bryson has said that some autistics have evidence of trauma to the
brain stem in early development, and that a small portion of the thalidomide
victims have become autistic. The victims' limbs were normal unless thalidomide
use continued later in the pregnancy. The brain stem anomaly's most striking
feature is inability to focus attention away from a stimulus in a short
time like neurotypicals, as demonstrated in a psychological test.
Some people claim the inability to shift attention quickly interferes
with the ability to read nonverbal language where fast attention shifts
are needed (such as eye language), suggesting that being nonverbal is
not a primary feature of autism. Strong and shiftless focus is however
a benefit in some areas like science, programming, and advanced mathematics.
This is supported by the monotropism hypothesis.
Dr. Bernard Rimland's influential research and his book Infantile Autism
(1967) argued that autism was not caused by childhood trauma or abuse,
but by damage to certain areas of the brain, particularly the reticular
formation which associates present sensory input with memories of past
experiences. Dr. Rimland is a foremost advocate of the theory that autism
may be precipitated by mercury and heavy metal toxicity. He also is
prominent in increasingly common claims of successful treatment of autism
in children—particularly regarding improvements in ability to comprehend
the spoken word—with the gluten-free, casein-free diet and mercury
chelation therapy.
Others claim Dr. Bernard Rimland's methods alleviate the symptoms of
heavy metal poisoning, but not autism. Curing heavy metal poisoning when
it is present is a worthy goal (it helps with IQ and other learning difficulties
as well as general health), but claiming a cure for autism is a misrepresentation.
Heavy metal poisoning may be more common among autistics due to a severe
metallothionein deficiency, but more evidence is needed to substantiate
the idea that heavy metals cause autism. It is still being studied. The
presence of heavy metals, particularly mercury, might make an autism diagnosis
more likely, however.
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