An investigation of sleep characteristics, EEG abnormalities and epilepsy in developmentally regressed and non-regressed children with autism

The role of epilepsy and epileptiform EEGs in autism spectrum disorders

Autism is a neurodevelopmental disorder of unknown etiology characterized by social and communication deficits and the presence of restricted interests/repetitive behaviors. Higher rates of epilepsy have long been reported, but prevalence estimates vary from as little as 5% to as much as 46%. This variation is probably the result of sample characteristics that increase epilepsy risk such as sample ascertainment, lower intelligence quotient (IQ), the inclusion of patients with nonidiopathic autism, age, and gender. However, critical review of the literature reveals that the rate in idiopathic cases with normal IQ is still significantly above the population risk suggesting that autism itself is associated with an increased risk of epilepsy. Recently, there has been interest in the occurrence of epileptiform electroencephalograms (EEGs) even in the absence of epilepsy. Rates as high as 60% have been reported and some investigators propose that these abnormalities may play a causal role in the autism phenotype. Although this phenomenon is still not well understood and risk factors have yet to be determined, the treatment implications are increasingly important. We review the recent literature to elucidate possible risk factors for both epilepsy and epileptiform EEGs. We then review existing data and discuss controversies surrounding treatment of EEG abnormalities.

Sleep problems in autism spectrum disorders: prevalence, nature, & possible biopsychosocial aetiologies

As considerably more people are diagnosed with an autism spectrum disorder (ASD), interest in the associated behaviours, including sleep problems has increased. This has resulted in a subsequent increase in the research related to the sleep problems occurring in people with an ASD. This article summarizes and evaluates the current literature related to a) the higher prevalence of a sleep problem compared to typically developing children, b) the specific types of sleep problems for people with an ASD, and c) the possible aetiology of sleep problems in the ASDs within a biopsychosocial framework. It is concluded that recent studies confirm that the majority of this population are likely to experience sleep difficulties, with settling issues in children with an ASD the most commonly reported. However, exploration of the types of sleep difficulties and associated aetiological factors in the ASDs is still in its infancy.

Convulsing toward the pathophysiology of autism

The autisms and epilepsies are heterogeneous disorders that have diverse etiologies and pathologies. The severity of impairment and of symptoms associated with autism or with particular epilepsy syndromes reflects focal or global, structurally abnormal or dysfunctional neuronal networks. The complex relationship between autism and epilepsy, as reflected in the autism-epilepsy phenotype, provides a bridge to further knowledge of shared neuronal networks that can account for both the autisms and the epilepsies. Although epilepsy is not a causal factor for autism, increased understanding of common genetic and molecular biological mechanisms of the autism-epilepsy phenotype has provided insight into the pathophysiology of the autisms. The autism-epilepsy phenotype provides a novel model to the study of interventions that may have a positive modulating effects on social cognitive outcome.