Hemispheric Coherence in ASD with and without Comorbid ADHD and Anxiety.

A Saunders,K E Waldie,I J Kirk

doi:10.1155/2016/4267842

Abstract

There is a growing body of evidence suggesting that altered brain connectivity may be a defining feature of disorders such as autism spectrum disorder (ASD), anxiety, and ADHD. This study investigated whether resting state functional connectivity, measured by 128-channel EEG oscillation coherence, differs between developmental disorders. Analyses were conducted separately on groups with and without comorbid conditions. Analyses revealed increased coherence across central electrodes over the primary motor cortex and decreased coherence in the frontal lobe networks in those with ASD compared to neurotypical controls. There was increased coherence in occipital lobe networks in the ADHD group compared to other groups. Symptoms of generalised anxiety were positively correlated with both frontal-occipital intrahemispheric (alpha only) coherence and occipital interhemispheric coherence (alpha, approaching theta band). The patterns of coherence in the ASD pure group were different when comorbid conditions were included in the analyses, suggesting that aberrant coherence in the frontal and central areas of the brain is specifically associated with ASD. Our findings support the idea that comorbid conditions are additive, rather than being symptoms of the same disorder.

Highlights

Brain connectivity describes the pattern of links between regions of our brain
A 2 × 4 (ADHD, anxiety, autism spectrum disorder (ASD), and control) multivariate ANOVA was conducted on the eyes closed alpha band coherence values
The analyses revealed differential patterns of coherence in the ASD group

Summary

Introduction

Brain connectivity describes the pattern of links between regions of our brain. Connectivity is broadly split into functional connectivity (which describes the similarity of temporal characteristics of brain activity in different brain regions) or structural connectivity (the physical connections of regions) [1]. Communication and integration of segregated areas or networks of the brain are vital for the successful execution of cognitive and motor functions [2]. Measuring synchronisation or coherence of EEG while the brain is at rest is a common method with which to gauge cortical functional connectivity. Resting state connectivity measures allow investigators to study the flow of mental events in the absence of task performance (which requires the employment of task specific regions). Brain activation during resting state connectivity investigations can be used as a measure of baseline brain activity [3]

Objectives

Results

Discussion

Conclusion