Association Between Magnetoencephalographic Interictal Epileptiform Discharge and Cognitive Function in Young Children With Typical Development and With Autism Spectrum Disorders.

Tetsu Hirosawa,Mina Fukai,Yoshio Minabe,Kyung-Min An,Shoryoku Hino,Tatsuru Kitamura,Paul Sowman,Tetsuya Takahashi,Yoshiaki Miyagishi,Mitsuru Kikuchi,Yuko Yoshimura

doi:10.3389/fpsyt.2018.00568

Abstract

Electroencephalograms of individuals with autism spectrum disorders (ASD) show higher rates of interictal epileptiform discharges (IEDs), which are known to have an inverse association with cognitive function in typically developed (TD) children. Nevertheless, that phenomenon has not been investigated adequately in children with ASD. From university and affiliated hospitals, 163 TD children (84 male, 79 female, aged 32–89 months) and 107 children (85 male, 22 female, aged 36–98 months) with ASD without clinical seizure were recruited. We assessed their cognitive function using the Kaufman Assessment Battery for Children (K-ABC) and recorded 10 min of MEG. Original waveforms were visually inspected. Then a linear regression model was applied to evaluate the association between the IED frequency and level of their cognitive function. Significantly higher rates of IEDs were found in the ASD group than in the TD group. In the TD group, we found significant negative correlation between mental processing scale scores (MPS) and the IED frequency. However, for the ASD group, we found significant positive correlation between MPS scores and the IED frequency. In terms of the achievement scale, correlation was not significant in either group. Although we found a correlative rather than a causal effect, typically developed children with higher IED frequency might better be followed up carefully. Furthermore, for children with ASD without clinical seizure, clinicians might consider IEDs as less harmful than those observed in TD children.

Highlights

Autism spectrum disorder (ASD) is a lifelong, often severely impairing neurodevelopmental syndrome characterized by impaired social cognition and communication as well as repetitive or obsessive behavior and interests [1]
We investigate the association between interictal epileptiform discharges (IEDs) and cognitive function in children with autism spectrum disorders (ASD) and compare it with that in typically developing children of a control group
We examined the relation between variables using a series of scatterplots and augmented component-plus-residual plots for the variables (i.e., mental processing scale scores (MPS) or Achievement Scale (ACH) scores and frequency of IEDs)

Summary

INTRODUCTION

Autism spectrum disorder (ASD) is a lifelong, often severely impairing neurodevelopmental syndrome characterized by impaired social cognition and communication as well as repetitive or obsessive behavior and interests [1]. Results of recent studies suggest that ID in ASD might emerge as a consequence of social-communication deficits According to this model, because social input is crucially important for normal brain development [6], poor sociality in children with ASD stunts their cognitive development by precluding them from social experience [6, 7]. Because animal studies showed that IED effects on cognitive function in children might be different from the effects in adults [31], results found for inhomogeneous populations might not reflect the true relation. A noteworthy exception is a study conducted by Gillian et al with no such limitations [27] They found no correlation between the IED frequency and cognitive dysfunction in children with ASD. We used magnetoencephalography (MEG) instead of EEG because it is more sensitive to epileptiform activity [32]

Participants

RESULTS

DISCUSSION