Evolution of EEG findings in children with autism spectrum disorder: A tertiary care centre's clinical experience

Abstract

Epilepsy and Autism Spectrum Disorder (ASD) are frequently co-morbid conditions. There are no clear testing modalities or biomarkers to distinguish children with ASD who are at risk for developing epileptic seizures from those who are not. Epileptiform electroencephalogram (EEG) abnormalities are common in children with ASD, suggesting a possible shared underlying pathophysiology with epilepsy. Our study analysed EEGs in children with ASD who underwent serial EEG studies. We show that initial EEG classification was a significant prognosticator for future EEG findings (p < 0.0001). Our study failed to demonstrate a statistically significant difference in the presence of epileptiform EEGs in children with ASD and co-morbid epilepsy as compared to those without co-morbid epilepsy. Furthermore, analysis of children with ASD and developmental regression or ASD and language impairment failed to demonstrate statistically significant differences in presence of epileptiform EEG abnormalities. Together these findings suggest that repeat EEGs should be obtained on a case-by-case basis in children with ASD and epileptiform EEG abnormalities in ASD in the absence of convincing epileptic seizures should be cautiously interpreted.

Autism, Epilepsy and Intellectual Disability: A Clinical Conundrum

“…It is unclear whether autism leads to epilepsy or it is the other way around. Similarly, whether the combination of the two leads to cognitive decline or a significantly low intellect is an independent risk factor for epilepsy in autism, is debatable [3]. Moreover what to do if an abnormality is detected on EEG, especially when clinical seizures are absent, make a protocolized management plan elusive.…”

“…Pediatricians should consider autism as an age dependent symptom complex of multifactorial and diverse etiology which either manifests alone as 'essential' autism or as a part of a more pervasive disorder such as tuberous sclerosis, electrical status epilepticus in sleep (ESES), progressive neurodegenerative or metabolic disorders [4]. In the latter type of presentation, there should be a high index of suspicion for co-morbid conditions including epilepsy and a low threshold for treatment of the same [3]. For those presenting with 'essential' autism, EEG should be reserved in cases with seizures or events that may represent seizures or with clear language regression [5].…”

“…Along with it, diagnosing seizure in autism may be difficult as the behavioral and motor stereotypes associated with some seizure types may mimic autistic behavior traits. Due to this ambiguity, guidelines discourage screening EEG in absence of clinical seizure [3]. If a clinician decides to order an EEG, it should preferably be a 30 min sleep record with arousal/awake response with or without intermittent photic stimulation.…”