Quantitative electroencephalographic changes in children with autism spectrum disorders

Abstract

Background Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by impairment of social interaction, communication, and behavior. It has been recently suggested that ASD are characterized by abnormal brain networks and connectivity, which was studied using neuroimaging modalities. Objective The aim of this study is to assess the quantitative electroencephalographic (QEEG) findings in children with ASD compared with age-matched children and to assess if QEEG analysis is a sensitive and simple method to aid in the diagnosis of ASD in children. Patients and methods QEEG recordings of 50 children with ASD between the ages of 2 and 6 years were compared with those of 50 age-matched controls under eyes-closed condition. Brain functioning and its connectivity were examined using measurements of spectral analysis of both absolute and relative power and interhemispheric coherence. Results There were statistically significant differences in electroencephalogram spectral power and coherence between the study and control groups. It revealed an increased absolute delta power in the frontal, anterior temporal, midtemporal, central, and parietal regions and an increase of absolute alpha power mainly in the prefrontal and frontal regions. There was a greater beta power in midtemporal and posterior temporal regions. In addition, interhemispheric coherence showed a pattern of frontal overconnectivity and temporal underconnectivity with the other brain areas in children with ASD in comparison with the control group. Moreover, statistical differences in electroencephalogram spectral power and coherence between the different grades of children with ASD were noticed. Conclusion These results suggested that children with ASD have QEEG dysfunctions that underlie their symptomatology. Hence, QEEG provides a useful method that aids in the diagnosis of children with ASD.