Sleep Characteristics in Patients with Autism Spectrum Disorders

Autism Spectrum Disorder (ASD) is a heterogeneous, behaviorally defined neurodevelopmental disorder. Patients with ASD might also have co-morbid disorders such as intellectual impairment, epilepsy, and anxiety. Findings from questionnaire studies have revealed the existence of several sleep problems in pediatric patients with ASD. However, few studies have analyzed the relationship between these disturbances and Polysomnographic (PSG) findings. On the other hand, about a third of people with autism also suffer from epilepsy. For this reason, long-duration electroencephalograms including an adequate amount of slow wave sleep should be carried out in order to detect epileptiform activity. The aim of this work is to describe the sleep characteristics and to detect EEG anormalities in ASD patients using polysomnographic recordings. Methods: Polysomnographic recordings were carried out in 12 autistic children for two consecutive nights and compared to those of the age and sex-matched controls. Sleep efficiency as well as percentages of each sleep phase were obtained from the two groups of participating children. Distribution of SWS and REM sleep throughout the night was also obtained and compared between both groups. Simultaneously, EEG characteristics were analyzed and compared. Results: ASD children presented low sleep efficiency, fragmented sleep and reduction in both SWS and REM sleep. Epileptifom brain activity was observed in 50% of ASD children. Conclusion: ASD patients presented quantitative and qualitative sleep disturbances as well as EEG abnormalities. IntroductIon Autism Spectrum Disorder (ASD) is a heterogeneous, behaviorally defined, neurodevelopmental disorder that occurs in 1 of 150 children [1]. Individuals with autism have deficits in social interaction and verbal and nonverbal communication, as well as in restricted or stereotyped patterns of behavior [2]. These patients might also have co-morbid disorders such as intellectual impairment, epilepsy, and anxiety. Epilepsy is associated with pathology of multiple brain regions, among which the cerebral cortex, amygdale, cerebellum, and hippocampal formation are included. These brain regions have also been implicated in autism [1]. Postmortem and magnetic resonance imaging studies have highlighted the frontal lobes, amygdale, and cerebellum as pathological regions in autism. Despite these findings, no unambiguous and consistent pathology has emerged for this neurodevelopmental disorder. Additionally, recent studies emphasize that disturbances in the time course of brain development are fundamental in ASD [3]. It has been suggested that the heterogeneity of both the core and co-morbid features is related to the heterogeneous pattern of the neuropathology observed in ASD patients. In this context, defined phenotypes in larger samples of children and well-characterized brain damage are indispensable to elucidate the neuroanatomy of ASD. The neurological and social deficits observed in autistic patients contribute to varying levels of impairment. Recent advancements in autism research have improved the understanding of the disorder; however, numerous questions about the pathophysiology of ASD remain without precise answers. The expression of ASD is extremely heterogeneous due to the complex interactions between genes, the central nervous system, and the behavior throughout development. Therefore, some researchers refer to ‘the autisms’ or ASD rather than a single autism phenotype [4]. *Corresponding author Fructuoso Ayala-Guerrero, Department of Psychology, Laboratory of Neurosciences, National Autonomous University of Mexico, University Avenue, Ciudad City, CP 04510, Mexico, Tel: 5622-2222 #41243; Email: Submitted: 26 February 2014 Accepted: 17 March 2014 Published: 24 March 2014 Copyright © 2014 Ayala-Guerrero et al.