- Autism spectrum disorders (ASD's) are diagnosed on an average at
about 3 to 4 years of age based on behavioral impairments.
- Earlier diagnosis is essential to initiate appropriate
interventions that improve the long-term prognosis for the child.
- The research team has shown that increased
cerebrospinal fluid (CSF) in infants detected by magnetic resonance
imaging (MRI) could predict autism risk at 6 months.
diagnosed with autism at 2 years age had significantly higher amounts of
cerebrospinal fluid (CSF) at 6 months and 12 months compared to normal children
according to a study led by Joseph Piven, MD belonging to UNC
School of Medicine.
Reason for the Study
Autism spectrum disorders
(ASDs) are developmental disorders associated
with impaired social and communication skills, associated with repetitive
‘Cerebrospinal Fluid imaging of infants could help predict autism risk earlier in order to initiate necessary interventions sooner so that long term outcomes are better for the child’
Studies have shown that early diagnosis of autism and initiation of
interventions help in decreasing the impairments and improves the
for the child.
However at present, there are no biological markers
to predict the risk of autism in infants early and typically diagnosis is made on an average
at around 4
years due to impaired behavioral patterns. Studies have shown
that babies who have an older sibling diagnosed with ASD might be at an increased risk of being diagnosed with
There are indications that biological
differences such as larger head size at 4 to 6 months of age and alterations in
the organization of white matter might predict autism diagnosis later. However, it is not clear whether MRI can detect
clinically significant structural variations in infants at higher risk for ASD
and if these are associated with development of ASD.
of the study was to determine if any consistently observable MRI findings as
early as 6 months might differentiate infants who develop ASD from normal
or occurrence of other developmental delays.
Details and Findings of the Study
The present study included 343 children,
of which 221 were at increased risk for development of autism
they had an older sibling diagnosed with autism. Forty-seven of these children went on to be
diagnosed with autism at 24 months. MRI's were taken at ages 6, 12 and 24
- The MRI's of the 6-month-olds who
were diagnosed with autism showed 18 percent more CSF compared to the 6-month-olds that
did not develop autism. The amount of CSF remained elevated even at 12
months and 24 months.
- Infants who developed severe autism
had even more (24 percent higher) CSF at 6 months compared to children who
were not diagnosed with ASD
- Higher amounts of CSF at 6 months
was associated with a greater impairment of gross motor skills such as
head and limb control.
"The CSF is easy to see on standard
MRIs and points to a potential biomarker of autism before symptoms appear years
later," said Piven, co-senior author of the study. According to Thomas E.
Castelloe Distinguished Professor of Psychiatry, and director of the Carolina
Institute for Developmental Disabilities (CIDD). "We also think this finding
provides a potential therapeutic target for a subset of people with
Newly Discovered Role of the CSF
Until recently it was believed that the
CSF was a protective cushion between the brain and the skull. Scientists recently found that the CSF acts to filter
out inflammatory proteins and other by-products
of brain metabolism. This
is then replaced by formation of new CSF four times a day in children as well
The findings of the study suggest that faulty CSF flow could be one of the causes
for autism risk,
possibly by affecting the developing brain.
"We know that CSF is very important
for brain health, and our data suggest that in this large subset of kids, the
fluid is not flowing properly," said Mark Shen, PhD, CIDD postdoctoral
fellow and first author of the study. "We don't expect there's a single
mechanism that explains the cause of the condition for every child. But we
think improper CSF flow could be one important mechanism."
In 2013, Shen co-led a similar study of
CSF in infants at UC Davis, and worked with David Amaral, PhD, co-senior author
of the current†study. Using MRIs, they found significantly higher amounts
of CSF in babies that went on to develop autism. They acknowledged the study
was small; it involved 55 babies and 10 went on to be diagnosed with autism. A
larger study was needed to substantiate the findings which led to the current
The authors found that CSF predicted with
nearly 70 percent accuracy, the risk for autism development. Although not a
perfect predictor, the differences are easily observable on MRI and this could
be used by child specialists as an additional tool for diagnosing autism risk
early and for possible intervention.
- Early brain enlargement and elevated extra-axial
fluid in infants who develop autism spectrum disorder - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3754460/)