Ictal EEG in patients with autistic spectrum disorder and epilepsy

Staring spells in children with autism spectrum disorder: A clinical dilemma

To assess the role of clinical features in diagnosing seizures in children with autism spectrum disorder who present with staring spells. A 10-year retrospective chart analysis of autism spectrum disorder patients aged 3–14 years was performed at a tertiary care children’s hospital. Patient demographics, clinical presentation, and epileptic seizure versus non-epileptic spell diagnosis were assessed. Target episodes of staring spells were captured during a long-term electroencephalogram monitoring record. Multilevel likelihood ratios and a receiver operating characteristic curve were determined using 8 of the 11 clinical variables. Among the cohort of 140 patients with autism spectrum disorder, 16% were diagnosed with epileptic seizures with the most common seizure being atypical absence seizures (64%). Clinical semiology differed between those diagnosed with epileptic seizures versus those diagnosed with non-epileptic spells in the average duration of episodes (42 s vs 87 s), frequency of spells per week (6 vs 11.5 spells), increase in frequency of staring spells over time (100% vs 40%), and response to verbal stimulation (0% vs 100%), respectively. Multilevel likelihood ratios based on the receiver operating characteristic curves and clinical semiology features may be helpful in differentiating epileptic seizures from non-epileptic spells in children with autism spectrum disorder.

Lay Abstract

It is a common occurrence for children with autism spectrum disorder to be diagnosed with staring spells. Staring spells are defined as periods of time when children “space out” and are subcategorized as either “absence seizures” (brain activity resembling a seizure but with no physical seizure symptoms) or “non-epileptic spells” (inattentiveness or daydreaming). Due to the subtle characteristics of staring spells, they are usually diagnosed via long-term video electroencephalogram. The child is monitored for 3–5 days with an electroencephalogram which records brain waves. An electroencephalogram may be difficult to perform in children with autism spectrum disorder due to behavior, cognitive, or sensory concerns. Therefore, we wanted to investigate other clinical characteristics that may help us differentiate between epileptic seizures versus non-epileptic spells in children with autism spectrum disorder presenting with staring spells. We reviewed 140 charts retrospectively from the years of 2010–2021. We abstracted demographic and clinical information from the electronic medical record system and reviewed electroencephalogram videos to group the 140 children into epileptic seizure diagnosis group versus non-epileptic spell group. Of the 140 children in this study, 22 were diagnosed with epileptic seizures and the remaining were diagnosed with non-epileptic spells. We found that the two groups differed in certain clinical characteristics such as how long the staring spells lasted, how many staring spells the child had in 1 week, and whether they responded to verbal commands. We believe that clinical features may be helpful in differentiating epileptic seizures from non-epileptic spells in children with autism spectrum disorder.

Electroencephalogram Abnormalities and Epilepsy in Autism Spectrum Disorders: Clinical and Electroencephalogram Findings

It has been known for several decades that epilepsy and autism spectrum disorders (ASD) are related to each other. Epilepsy frequently accompanies ASD. The purpose of this study was to investigate relationship between clinical and electroencephalogram (EEG) findings in ASD patients and to identify EEG characteristics that may create a disposition to epilepsy in ASD by examining differences in clinical and EEG findings between patients diagnosed with ASD without epilepsy and ASD with epilepsy. A total of 102 patients aged 2 to 18 years and diagnosed with ASD based on Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) diagnostic criteria between January 2017 and June 2019 were included in the study. Patients were assigned into two groups: (1) ASD with epilepsy and (2) ASD without epilepsy. Clinical findings were retrieved from patients' files, and EEG findings from first EEG records in the EEG laboratory at the time of diagnosis. EEG findings were defined as central, parietal, frontal, temporal, or generalized, depending on the location of rhythmic discharges. The incidence of epilepsy in our ASD patients was 33.7% and that of febrile convulsion was 4%. Generalized motor seizures were the most common seizure type. Epileptic discharges most commonly derived from the central and frontal regions. These abnormalities, especially frontal and central rhythmic discharges, may represent a precursor for the development of epilepsy in ASD patients.