Extremely/Very Premature Birth Associated With Focal Epileptic Activity in Comorbid Autism and Epilepsy

Abstract

BackgroundAutism spectrum disorder and epilepsy commonly occur together (ASD+EPI), suggesting shared pathology. However, epilepsy phenotypes within ASD+EPI are very heterogenous. Preterm birth poses a risk for both autism and epilepsy, and therefore may have a distinctive phenotype.MethodsWe used clinical EEG reports from more than 200 patients diagnosed with ASD+EPI and extracted lateralization and location data across multiple EEG time points. We analyzed epilepsy phenotypes between children born <32 weeks, 32-36⁺⁶, and 37-40⁺⁶ weeks to determine whether gestational age at birth impacts propensity for focal vs generalized epileptic activity.ResultsPatients with a history of birth before 32 weeks' gestational age had increased incidence of focal interictal activity compared with patients born after 32 weeks. There were no differences in seizure or interictal categorization between patients born moderately/late preterm and those born at term.ConclusionsThese results suggest that patients born extremely/very preterm who develop ASD+EPI have a predisposition toward focal epileptic activity, which may be due to changes in white matter development following very preterm birth.

Keywords: EEG; autism; electroencephalography; epilepsy; preterm.

Figure 1.

Categorization of Interictal Epileptiform Discharges across gestational age groups. Patients with a history of extremely/very premature birth had significantly higher (Chi-Square test, p=0.035) incidence of focal interictal activity compared to patients born at or after 32 weeks. P-value is generated from the number of patients in each category, not the percentages (numbers listed in Table 1).

Figure 2.

Seizure and Interictal Epileptiform Discharge categorization between moderately/late preterm patients and patients born at term. A) Unlike patients born EVPT, MLPT patients seemed to have a higher incidence of generalized seizures (88.9%) compared to term patients (50%), while B) IED categorization across groups was nearly identical.