Functional magnetic resonance imaging (fMRI) may serve as an early and objective indicator of autism, according to a study slated for publication in the August issue of Radiology. Already posted online, the study was conducted by researchers at Columbia University in New York City, who used the technique to document language impairment in autistic children.
To execute the study, the researchers performed fMRI exams on 15 control children with a mean age of 12.1and on 12 language-impaired and age-matched autistic children with a (mean age of 12.4. fMRI was used to measure neural activity in working brain tissues, while the children listened to recordings of their parents talking to them. The researchers then measured activation levels during passive stimulation within the primary auditory cortex (A1) and superior temporal gyrus (STG). Activity in the A1 region did not appear to differ between autistic and control patients, but activation within the STG was greater for control children relative to autistic patients.
"These findings first tell us that the autistic children in our study appeared normal with respect to the primary auditory system," says Joy Hirsch, Ph.D., a professor at Columbia University Medical Center and director of the Functional MRI Laboratory. "But it appears that the STG in the autistic brains was not as sensitive to the language narratives as was the STG in the brains of the typical children."
An additional 27 autistic children undergoing routine MRI exams with sedation were also included in the study. Via a similar analysis of sedation-adjusted values from the control group, the researchers identified 26 of 27 (96%) of sedated autistic patients with autism.
"This study suggests that fMRI acquired during listening to a language narrative can be used to distinguish children with autism from those without," Hirsch states. "Based on these initial findings, future studies using these or similar fMRI methods may result in an early and objective imaging indicator for autism."