Functional MRI May Indicate Language Disability in Autism
Difference in activation within the superior temporal gyrus in children with and without autism
WEDNESDAY, June 1 (HealthDay News) -- Functional magnetic resonance imaging (fMRI) may be used as an indicator of language impairment in children with autism, according to a study published online May 31 in Radiology.
Grace Lai, Ph.D., from Columbia University Medical Center in New York City, and colleagues investigated the use of fMRI as an indicator of language disability in children with autism. A total of 15 children (mean age, 12.1 years) without autism and 12 children with language impairment and autism (mean age, 12.4) underwent fMRI during passive presentations of pre-recorded speech. An additional 27 children with autism (mean age, 8.4) who underwent routine MRI scans with sedation were also included in the study. The spread and amplitude of fMRI activation were quantified in the primary auditory cortex (A1) and superior temporal gyrus (STG). The threshold for autism was defined as one standard deviation below the control mean for children who underwent nonsedated scans. A similar threshold was estimated for sedated children with autism.
The investigators found that there was no difference between children with and without autism in A1 activity, but there was a significant difference in the mean amplitude and spread of activity in the STG. Values for 10 of the 12 (83 percent) nonsedated children with autism decreased at least one standard deviation below the control distribution. By using the threshold derived from sedation-adjusted values of the control group it was possible to identify 26 of the 27 (96 percent) sedated children with autism.
"Functional MR imaging activation within the STG in response to passive speech stimulation helped differentiate autistic from control subjects, demonstrating the potential utility of functional MR imaging as an objective indicator of language impairment in autism," the authors write.