A study, led by the University of North Carolina at Chapel Hill, found that as early as six months old, high-risk infant brain scans show significant differences between an infant who develops autism and an infant who does not. This represents the earliest detection method for autism in children.
In this study, 92 infants, with older siblings with autism, were considered to be at high risk for autism. These infants were enrolled at six-months-old and underwent diffusion tensor imaging, a type of magnetic resonance imaging (MRI). Then at 24-months-old, the infants underwent a behavioral assessments. At 24 months, 28 infants (30 percent) showed signs for autism spectrum disorders, compared to 64 infants (70 percent) who did not.
Using fractional anisotropy (FA), white matter fiber tract development differed between these two infant groups. White matter fibers are crucial for brain function because white matter is made up of the neuron axons that are responsible for transmitting signals in the brain. Having different white matter fiber development affects how different pathways are connected in the brain, which could alter behavior and function. FA tracks water molecule movement through brain tissue, which measures white matter organization and development. Between the two infant groups, there were differences in white matter tracks among 12 of the 15 tracts examined.
Using FA, infants, who later developed autism, showed elevated FA at six-months-old, and over time, they experienced slower change. By two-years-old, infants, who developed autism, had lower FA values than infants without autism.
The study’s findings suggests that autism does not appear suddenly in children; however, instead autism develops gradually during infancy. This highlights the possibility that the process of developing autism can be stopped through targeted intervention.
Jason J. Wolff, PhD, lead author of the study and a postdoctoral fellow, admits that these findings are still preliminary, yet promising. He is optimistic to develop a biomarker for diagnosing autism.
This study was published in the journal American Journal of Psychiatry.
In the U.S., about one in 110 children have an autism spectrum disorder. Signs of autism include not giving full eye contact, lacking of interest in peer relationships, having delayed language development, and having persistent fixation on parts of objects.
Typically parents do not notice symptoms of autism until the infant is about one or two-years-old. Yet, on average, children are not diagnosed with autism until the age of five-years-old. In addition, many parents report that their child’s symptoms appeared suddenly, which contributes support for the idea that autism is caused by vaccines. However, this vaccine connection to autism is becoming less supported by science.
This study does have its criticisms. It is important to mention that this study involved only high-risk infants for autism. Lacking a control group of normal-risk infants could highlight a significant brain scan difference between all children. In addition, diagnosing autism spectrum disorders at two-years-old is earlier than when most children with autism are diagnosed. In addition, diagnoses of autism can occur later in life, as well. Thus, this study may be picking up differences between brain scans of the two groups prematurely of true autism outcomes.
