title: Clinical characteristics of children with autism spectrum disorder and co-occurring epilepsy.
abstract: OBJECTIVE
  To estimate the prevalence of epilepsy in children with Autism Spectrum Disorder (ASD) and to determine the demographic and clinical characteristics of children with ASD and epilepsy in a large patient population.
  
  
  METHODS
  Cross-sectional study using four samples of children with ASD for a total of 5,815 participants with ASD. The prevalence of epilepsy was estimated from a population-based sample. Children with and without epilepsy were compared on demographic and clinical characteristics. Multivariate logistic regression was used to examine the association between demographic and clinical characteristics and epilepsy.
  
  
  RESULTS
  The average prevalence of epilepsy in children with ASD 2-17 years was 12.5%; among children aged 13 years and older, 26% had epilepsy. Epilepsy was associated with older age, lower cognitive ability, poorer adaptive and language functioning, a history of developmental regression and more severe ASD symptoms. The association between epilepsy and the majority of these characteristics appears to be driven by the lower IQ of participants with epilepsy. In a multivariate regression model, only age and cognitive ability were independently associated with epilepsy. Children age 10 or older had 2.35 times the odds of being diagnosed with epilepsy (p<.001) and for a one standard deviation increase in IQ, the odds of having epilepsy decreased by 47% (p<.001).
  
  
  CONCLUSIONS
  This is among the largest studies to date of patients with ASD and co-occurring epilepsy. Based on a representative sample of children with ASD, the average prevalence of epilepsy is approximately 12% and reaches 26% by adolescence. Independent associations were found between epilepsy and older age and lower cognitive ability. Other risk factors, such as poor language and developmental regression, are not associated with epilepsy after controlling for IQ. These findings can help guide prognosis and alert clinicians to patients with ASD who are at increased risk for epilepsy.
authors.affiliation: Department of Epidemiology, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America.
authors.forename: Emma W
authors.initials: EW
authors.lastname: Viscidi
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Triche
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Pescosolido
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: McLean
authors.forename: Robert M
authors.initials: RM
authors.lastname: Joseph
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Spence
authors.forename: Eric M
authors.initials: EM
authors.lastname: Morrow
mesh_terms: D000293:Adolescent; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D002675:Child, Preschool; D003071:Cognition; D003430:Cross-Sectional Studies; D004827:Epilepsy / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007804:Language Development; D008297:Male; D011159:Population Surveillance; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D014481:United States / Q000453:epidemiology