Systematic Review on EEG Analysis to Diagnose and Treat Autism by Evaluating Functional Connectivity and Spectral Power

Figures & data

Figure 1 PRISMA flow diagram for further selecting some key journals. The inclusion and exclusion criteria were based on six factors; the year of publication, the country, language, subject, type of materials, and the population included. The studies were included if they were (a) published between 2007 to 2022 in any country worldwide, (b) written in English., (c) involved EEG signals in diagnosing ASD in children and adults with ASD disorder, and (d) peer-reviewed articles. The studies were also considered eligible if they included individuals with ASD diagnosed based on the Diagnostic and Manual of Mental Disorders, Fourth Edition (DSM-IV) and if the diagnosis was based on the individual’s age and intelligence quotient (IQ). Finally, the EEG signal analysis on functional connectivity and lower spectral power.

Notes: PRISMA figure adapted from Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. Syst Rev. 2021;10 (89). Creative Commons.

Table 1 Selected Studies Related to Functional Connectivity for an Overview of Relevant Advances in the Field

Paper	Number of Subjects (Those with ASD)	Control	Environment	Analysis	ASD Changes
Orekhova et al^Citation16	N=28; 18 females and 10 males	N/A	Video stimuli	Weighted phase lag index	It was found that there is hyper-connectivity in frontal and central areas
Righi et al^Citation17	N=Unspecified	N/A	Speech and Sound	Coherence analysis	Higher risk for people
Murias et al^Citation12	N=18	N=18 males	Eyes closed and relaxed	Coherence analysis	Increased frontal and temporal hemisphere and decreased frontal area
Boersma et al^Citation15	N=12; mean age 3.5 years	N=19	Using car pictures	Clustering analysis	The whole-brain activity was affected
Catarino et al^Citation13	N=15	N=15	Recognizing objects	Coherence analysis	Decreased coherence
Carson et al^Citation14	N=19	N=13 typically developing children; 9 males and 4 females	Videos of people reading a story	Coherence analysis	Decreased frontal and temporal lobes
Cantor et al^Citation18	N=11	N=88; Normal children but intellectually disabled N=18; Mentally handicapped children N=13; Mentally age-matched normal toddlers	Eyes open and relaxed	Coherence analysis	Increased coherence in delta and alpha band
Buckley et al^Citation19	N=87	N=21; Developmental delay without autism. N=29; typical development	Awake or in Low Sleep	Coherence analysis	Increased frontal coherence

Table 2 Selected Studies Related to Spectral Power for an Overview of Relevant Advances in the Field

Paper	Number of Subjects (Those with ASD)	Control	Condition	Measure	Changes in ASD
Sheikhani et al^Citation26	N=15	N=26 females and 29 males	Relaxed and eyes opened	Spectral properties	Alpha frequency power ratio was found to be reduced
Van Diessen et al^Citation27	N=Unspecified	N/A	Speech and Sound	Spectral power	Gamma power was found to be increased in frontal and temporal regions.
Stroganova et al^Citation28	N=40	N=40 males	Sustained visual issues	Spectral power	Issues of electrode location from myogenic artefacts
Yang et al^Citation25	N=5	N=7 with age-matched	Analysing known photographs	Spectral power	Decrease in the frequency range
Elhabashy et al^Citation30	N=21	N=21 with an age range of 4–12 years	Relaxed eyes movement	Absolute and relative spectral	Delta and that power was found to be increased in the frontal region
Lushchekina et al^Citation29	N=27	N=19 males and 8 females	Relaxed eyes movement and counting numbers	Alpha, beta, and gamma spectral power	Increase in spectral power and ASD gamma spectral power

Orekhova EV, Elsabbagh M, Jones EJ, Dawson G, Charman T, Johnson MH. EEG hyper-connectivity in high-risk infants is associated with later autism. J Neurodev Disord. 2014;6(1). doi:10.1186/1866-1955-6-40

 PubMedGoogle Scholar

Righi G, Tierney AL, Tager-Flusberg H, Nelson CA. Functional Connectivity in the First Year of Life in Infants at Risk for Autism Spectrum Disorder: an EEG Study. PLoS One. 2014;9(8):e105176. doi:10.1371/journal.pone.0105176

 PubMed Web of Science ®Google Scholar

Murias M, Webb SJ, Greenson J, Dawson G. Resting State Cortical Connectivity Reflected in EEG Coherence in Individuals with Autism. Biol Psychiatry. 2007;62(3):270–273. doi:10.1016/j.biopsych.2006.11.012

 PubMed Web of Science ®Google Scholar

Boersma M, Kemner C, de Reus MA, et al. Disrupted Functional Brain Networks in Autistic Toddlers. Brain Connect. 2013;3(1):41–49. doi:10.1089/brain.2012.0127

 PubMedGoogle Scholar

Catarino A, Andrade A, Churches O, Wagner AP, Baron-Cohen S, Ring H. Task-related functional connectivity in autism spectrum conditions: an EEG study using wavelet transform coherence. Mol Autism. 2013;4(1):1. doi:10.1186/2040-2392-4-1

 PubMedGoogle Scholar

Carson AM, Salowitz NMG, Scheidt RA, Dolan BK, Van Hecke AV. Electroencephalogram Coherence in Children with and Without Autism Spectrum Disorders: decreased Interhemispheric Connectivity in Autism. Autism Res. 2014;7(3):334–343. doi:10.1002/aur.1367

 PubMed Web of Science ®Google Scholar

Cantor DS, Thatcher RW, Hrybyk M, Kaye H. Computerized EEG analyses of autistic children. J Autism Dev Disord. 1986;16(2):169–187. doi:10.1007/bf01531728

 PubMed Web of Science ®Google Scholar

Buckley AW, Scott R, Tyler A, et al. State-Dependent Differences in Functional Connectivity in Young Children with Autism Spectrum Disorder. E Bio Med. 2015;2(12):1905–1915. doi:10.1016/j.ebiom.2015.11.004

 Google Scholar

Sheikhani A, Behnam H, Noroozian M, Mohammadi MR, Mohammadi M. Abnormalities of quantitative electroencephalography in children with Asperger disorder in various conditions. Res Autism Spectr Disord. 2009;3(2):538–546. doi:10.1016/j.rasd.2008.11.002

 Web of Science ®Google Scholar

van Diessen E, Senders J, Jansen FE, Boersma M, Bruining H. Increased power of resting-state gamma oscillations in autism spectrum disorder detected by routine electroencephalography. Eur Arch Psychiatry Clin Neurosci. 2014;265(6):537–540. doi:10.1007/s00406-014-0527-3

 PubMed Web of Science ®Google Scholar

Stroganova TA, Nygren G, Tsetlin MM, et al. Abnormal EEG lateralization in boys with autism. Clin Neurophysiol. 2007;118(8):1842–1854. doi:10.1016/j.clinph.2007.05.005

 PubMed Web of Science ®Google Scholar

Yang HH, Savostyanov AN, Tsai AC, Liou M. Face recognition in Asperger syndrome: a study on EEG spectral power changes. Neurosci Lett. 2011;492(2):84–88. doi:10.1016/j.neulet.2011.01.061

 PubMed Web of Science ®Google Scholar

Elhabashy H, Raafat O, Afifi L, Raafat H, Abdullah K. Quantitative EEG in autistic children. Egypt J Neurol Psychiatry Neurosurgery. 2015;52(3):176. doi:10.4103/1110-1083.162031

 Google Scholar

Lushchekina EA, Podreznaya ED, Lushchekin VS, Novototskii-Vlasov V, Strelets VB. Comparative Studies of EEG Theta and Gamma Rhythms in Normal Children and Children with Early Childhood Autism. Neurosci Behav Physiol. 2014;44(8):902–908. doi:10.1007/s11055-014-9999-x

 Google Scholar