The study, published online recently in the Journal of Neurodevelopmental Disorders, should guide other researchers working to better understand neurodevelopmental disorders such as autism.
“If we really want to understand the neural bases of autism, we have to figure out a way to include all children with autism, even those with more severe impairments, in MRI research studies,” said lead author Christine Wu Nordahl, assistant professor of psychiatry and behavioral sciences at UC Davis. “In this paper, we outline methods used to obtain high quality MRI images in children with very severe impairments without using general anesthesia. Much to our own surprise and pleasure, we were more successful than we hoped and obtained high quality images for all of the children tested thus far.”
MRI is an important tool for understanding the brain-based differences in children with autism, but getting an MRI requires the child to lie still in the scanner for anywhere up to 30 minutes and even the slightest head movements can lead to a bad MRI scan. Because most investigators assumed that this would be too difficult for more severely impaired children with ASD, most autism studies using MRI have included only children with IQ scores in the normal to above average range. Sedation or general anesthesia is typically used to get MRI scans of children with autism with lower IQ scores.
Sedation in children with ASD is considered safe, according to Nordahl, though anesthesia does pose a minimally increased risk. Some parents hesitate to put their children under when it is not medically necessary.
Many children with ASD receive applied behavior analysis as part of their intervention plans. The therapy, which involves positive reinforcement, also has been used to help prepare children with ASD for clinical visits, but hadn’t yet been used in research settings using MRI.
Nordahl and her team enlisted the help of trained behavior analysts to help children in the study with the MRI process. After initial conversations with parents to get an idea of what rewards work for their children, the behavior analysts acclimated the children to the MRI environment and helped them lie still long enough to get good images.
The research included 17 children with ASD who are participants in the UC Davis Autism Phenome Project, a comprehensive study of brain development from early to middle childhood. Children in the current study were between 9 and 13 years old.
To create a comfortable and safe environment for the participants, researchers used behavioral strategies aimed at increasing motivation and the child’s sense of control, peer modeling, verbal reminders, visual timers and countdowns.
The children were supported throughout the entire process and given either social or tangible reinforcement after they had successfully completed each step.
For all patients, only one MRI visit was necessary to acquire high-quality brain scans. Some children required multiple attempts, but all 17 eventually had scans without the use of sedation.
“The use of applied behavior analysis mixed with time and support created a very high success rate,” Nordahl said. “MRI is one of the best and safest ways to look at the brain, and children with more severe impairments have been under-represented in research studies. This method requires patience but could give researchers a way to give more children with autism the research attention they deserve.”
Other study authors include Melissa Mello, Audrey Shen, Mark Shen, Laurie Vismara, Deana Li, Kayla Harrington, Costin Tanase, Beth Goodlin-Jones, Sally Rogers, Leonard Abbeduto and senior author David Amaral, all of UC Davis.
The study was funded by the National Institutes of Health (grant numbers U54 HD079125, R01MH104438-0151 and R01MH103371) and the UC Davis MIND Institute Intellectual and Developmental Disabilities Research Center.
The UC Davis MIND Institute in Sacramento, Calif., was founded in 1998 as a unique interdisciplinary research center where families, community leaders, researchers, clinicians and volunteers work together toward a common goal: researching causes, treatments and eventual preventions and cures for neurodevelopmental disorders. The institute has major research efforts in autism, fragile X syndrome, chromosome 22q11.2 deletion syndrome, attention-deficit/hyperactivity disorder (ADHD) and Down syndrome. More information about the institute is available online at mindinstitute.ucdavis.edu