Dyslexia 'seen in brain scans' of pre-school children

Brain scans may allow detection of dyslexia
in pre-school children even before they
start to read, say researchers.
A US team found tell-tale signs on scans that
have already been seen in adults with the
condition.
And these brain differences could be a cause
rather than a consequence of dyslexia -
something unknown until now - the Journal of
Neuroscience reports.
Scans could allow early diagnosis and
intervention, experts hope.
The part of the brain affected is called the
arcuate fasciculus.
Shrinkage
Among the 40 school-entry children they
studied they found some had shrinkage of this
brain region, which processes word sounds
and language.
They asked the same children to do several
different types of pre-reading tests, such as
trying out different sounds in words.
Those children with a smaller arcuate
fasciculus had lower scores.
It is too early to say if the structural brain
differences found in the study are a marker of
dyslexia. The researchers plan to follow up
groups of children as they progress through
school to determine this.
Lead researcher Prof John Gabrieli said: "We
don't know yet how it plays out over time, and
that's the big question.
"We do not know how many of these children
will go on to develop problems. But anyway,
we want to intervene before that, and the
younger you do that the better. We already
know that reading programmes and
interventions can really help."
Early intervention
In the study, the volume of the left arcuate
had a particularly strong link with poorer pre-
reading test results.
The left arcuate fasciculus connects an area of
the brain involved in speech production with
another used to understand written and spoken
language.
A larger and more organised arcuate fasciculus
could aid in communication between those two
regions, the researchers say.
Prof Gabrieli said: "This brain area fits with a
lot of what we already know. So it's a good
candidate."
A few years ago, US doctors described the case
of a child who developed dyslexia after
radiation treatment for a brain tumour. The
same brain region - the arcuate fasciculus -
was involved.
A spokeswoman for the British Dyslexia
Association said brain imaging was providing
"increasing evidence" of notable differences
between the brains of people with and without
dyslexia.
"It is particularly exciting to envisage a future
where this technology could be part of a
cluster of indicators that would identify a risk
of dyslexic difficulties," she said.
But she said there needed to be far more
research to determine if in the future it might
be possible to diagnose dyslexia with a brain
scan

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