A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Spring, 2017 | Number 2, Volume 31

Excess CSF may be early clue in autism

Excess cerebrospinal fluid (CSF) in one region of the brain may be a very early marker for autism risk, a new study suggests. 

In a small 2013 pilot study, Mark Shen and colleagues at UC Davis detected substantially greater volumes of CSF in babies who later developed autism. In the new study, Shen collaborated with colleagues at the University of North Carolina at Chapel Hill to study 343 infants, 221 of whom were at high risk of developing ASD because they had a sibling with an ASD diagnosis. Forty-seven of these children later developed ASD. 

Analyzing MRI scans of the infants’ brains, the researchers found that many of those later diagnosed with autism had a significantly greater amount of CSF between the brain and skull—called extra-axial CSF—at 6 and 12 months of age than infants who did not become autistic. In addition, the more CSF detected at 6 months, the more severe autistic symptoms were at 2 years of age. 

The CSF between the brain and the skull acts as a filtration system for the byproducts of brain metabolism. Study coauthor Joseph Piven says, “We can’t yet say for certain that improper CSF flow causes autism. But extra-axial CSF is an early marker, a sign that CSF is not filtering and draining as it should. This is important because improper CSF flow may have downstream effects on the developing brain; it could play a role in the emergence of autism symptoms.” 

Piven adds, “The CSF is easy to see on standard MRIs and points to a potential biomarker of autism before symptoms appear years later. We also think this finding provides a potential therapeutic target for a subset of people with autism.”


“Increased extra-axial cerebrospinal fluid in high-risk infants who later develop autism,” Mark D. Shen, Sun Hyung Kim, Robert C. McKinstry, Hongbin Gu, Heather C. Hazlett, Christine W. Nordahl, Robert E. Emerson, Dennis Shaw, Jed T. Elison, Meghan R. Swanson, Vladimir S. Fonov, Guido Gerig, Stephen R. Dager, Kelly N. Botteron, Sarah Paterson, Robert T. Schultz, Alan C. Evans, Annette M. Estes, Lonnie Zwaigenbaum, Martin A. Styner, David G. Amaral, Joseph Piven, and the IBIS Network, Biological Psychiatry, March 6, 2017. Address: Mark Shen, University of North Carolina at Chapel Hill School of Medicine, Carolina Institute for Developmental Disabilities, Campus Box #3366, Chapel Hill, NC 27599. [email protected]


“Researchers link increased infant brain fluid to autism,” news release, University of North Carolina, March 7, 2017