Magnetoencephalography in the study of children with autism spectrum disorder

Abstract

Magnetoencephalography (MEG) is a non-invasiveneuroimaging technique that provides a measure of cortical neural activity on a millisecond timescale with high spatial resolution. MEG has been clinically applied to various neurological diseases, including epilepsy and cognitive dysfunction. In the past decade, MEG has also emerged as an important investigatory tool in neurodevelopmental studies. It is therefore an opportune time to review how MEG is able to contribute to the study of atypical brain development. We limit this review to autism spectrum disorder (ASD). The relevant published work for children was accessed using PubMed on 5 January 2015. Case reports, case series, and papers on epilepsy were excluded. Owing to their accurate separation of brain activity in the right and left hemispheres and the higher accuracy of source localization, MEG studies have added new information related to auditoryevoked brain responses to findings from previous electroencephalography studies of children with ASD. In addition, evidence of atypical brain connectivity in children with ASD has accumulated over the past decade. MEG is well suited for the study of neural activity with high time resolution even in young children. Although further studies are still necessary, the detailed findings provided by neuroimaging methods may aid clinical diagnosis and even contribute to the refinement of diagnostic categories for neurodevelopmental disorders in the future.Key words: auditory-evoked field, autism spectrum disorder, connectivity, magnetoencephalography, young children. MAGNETOENCEPHALOGRAPHY IN YOUNG CHILDRENM AGNETOENCEPHALOGRAPHY (MEG) AND electroencephalography (EEG) are non-invasive methods for recording neural activity. Contrary to functional magnetic resonance imaging and singlephoton emission computed tomography, which measure a hemodynamic response linked to metabolic demand, MEG and EEG measure a direct consequence of the electrical activity of neurons. These two techniques have a temporal resolution of approximately 1 ms, which is the typical resolution of measurable electrical phenomena in the brain. These two techniques have advantages over other neuroimaging techniques for use in young children, including fewer constraints and the absence of radiation and unpleasant sounds.MEG has been in development for human use since the 1960s, and its development has been greatly

A theoretical rut: revisiting and critically evaluating the generalized under/over‐connectivity hypothesis of autism

“…Among children who passively viewed engaging videos (chosen by each child), there were no differences in local power at any of the sensors, but there was greater gamma band coherence between right parietal and temporal sensor locations in the children with autism. In a subsequent study with a larger sample using the same task, Kikuchi et al (2015) found reduced theta coherence between left anterior and right posterior source locations in the children with autism, that predicted ADOS total scores.…”

“…In a subsequent study with a larger sample using the same task, Kikuchi et al . () found reduced theta coherence between left anterior and right posterior source locations in the children with autism, that predicted ADOS total scores.…”

“…Relatively few task-based functional connectivity studies have been conducted in MEG that meet our inclusion criteria, and fewer types of tasks have been examined than in studies using fMRI. Researchers have employed passive viewing of videos (Kikuchi, Yoshimura, Shitamichi, Ueno, Hirosawa et al, 2013;Kikuchi, Yoshimura, Mutou & Minabe, 2015), and of faces and houses (Khan, Gramfort, Shetty, Kitzbichler, Ganesan et al, 2013). Kikuchi et al (2013) examined long-range functional connectivity (coherence) using a custom-MEG system designed for children.…”

Auditory structural connectivity in preterm and healthy term infants during the first postnatal year

“…Another limitation is that we only measured the structure of the pathways, and not auditory function. Other studies have focused on the association between white matter maturation in the auditory cortex and singlecell electrophysiology in animal models, or used other techniques (i.e., Magnetoencephalography, Electroencephalography) to examine the development of human auditory cortex function during both typical and atypical development (Edgar et al, 2015;Kikuchi, Yoshimura, & Minabe, 2015;Roberts et al, 2009;Roberts, Lanza, Dell, Qasmieh, & Hines, 2014). Future multimodal studies, therefore, are needed in order to follow the specific development of these pathways and relate them with the development of auditory processing abilities.…”

Assessing Neuroplasticity Using Magnetoencephalography (MEG) in Patient with Left-Temporo-Parietal Pilocytic Astrocytomas Treated with Endoscopic Surgery

“…The role of neuroimaging techniques such as Magnetoencephalography (MEG) in evaluating brain activities and function has been subject to numerous report (Majchrzak et al 2012). There are many research reports describing the role and clinical applications of MEG in assessing auditory, motor and visual processing (Fruchter & Marantz 2015;Liu, Harris & Kanwisher 2002;Hund et al 1997;Hara et al 2007;Kikuchi et al 2015). Moreover, MEG technique is also used for mapping onto patients with neurological disorders or brain damage to further understand the effect of morbidity and mechanism of neuroplasticity to the brain function (Idris et al 2014;Kakisaka et al 2013).…”