A Multimodal Study of the Contributions of Conduction Velocity to the Auditory Evoked Neuromagnetic Response: Anomalies in Autism Spectrum Disorder
Abstract
This multimodal imaging study used magnetoencephalography, diffusion magnetic resonance imaging (MRI), and gamma‐aminobutyric acid (GABA) magnetic resonance spectroscopy (MRS) to identify and contrast the multiple physiological mechanisms associated with auditory processing efficiency in typically developing (TD) children and children with autism spectrum disorder (ASD). Efficient transmission of auditory input between the ear and auditory cortex is necessary for rapid encoding of auditory sensory information. It was hypothesized that the M50 auditory evoked response latency would be modulated by white matter microstructure (indexed by diffusion MRI) and by tonic inhibition (indexed by GABA MRS). Participants were 77 children diagnosed with ASD and 40 TD controls aged 7–17 years. A model of M50 latency with auditory radiation fractional anisotropy and age as independent variables was able to predict 52% of M50 latency variance in TD children, but only 12% of variance in ASD. The ASD group exhibited altered patterns of M50 latency modulation characterized by both higher variance and deviation from the expected structure–function relationship established with the TD group. The TD M50 latency model was used to identify a subpopulation of ASD who are significant “outliers” to the TD model. The ASD outlier group exhibited unexpectedly long M50 latencies in conjunction with significantly lower GABA levels. These findings indicate the dependence of electrophysiologic sensory response latency on underlying microstructure (white matter) and neurochemistry (synaptic activity). This study demonstrates the use of biologically based measures to stratify ASD according to their brain‐level “building blocks” as an alternative to their behavioral phenotype.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 14, 2020
- Source ID
- 10.1002/aur.2369
Entities
People
- Carissa R. Jackel
- J Christopher Edgar
- Jeffrey Berman
- Lisa Blaskey
- Luke Bloy
- Matt Ku
- Timothy Roberts
Organizations
- Children's Hospital of Philadelphia
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- National Institute of Mental Health
- National Institute on Deafness and Other Communication Disorders
- United States Department of Defense
- University of Pennsylvania