EEG abnormalities and epilepsy in autistic spectrum disorders: Clinical and familial correlates Ozalp Ekinci a, * , Ays ße Rodopman Arman b , Ug ˘ur Is ßık c , Yasin Bez d , Meral Berkem b a Antakya State Hospital of Obstetrics and Child Care, Antakya, Turkey b Department of Child and Adolescent Psychiatry, Marmara University, Istanbul, Turkey c Division of Pediatric Neurology, Department of Pediatrics, Acibadem University, Istanbul, Turkey d Psychiatry Clinic, Ergani State Hospital, Diyarbakir, Turkey article info Article history: Received 2 October 2009 Revised 13 November 2009 Accepted 18 November 2009 Available online 29 December 2009 Keywords: Autistic spectrum disorder Autism Electroencephalography Epilepsy Interictal EEG abnormality abstract Our aim was to examine the characteristics of EEG findings and epilepsy in autistic spectrum disorders (ASD) and the associated clinical and familial risk factors. Fifty-seven children (86% male) with ASD, mean age 82 ± 36.2 months, were included in the study. Thirty-nine (68.4%) children had the diagnosis of aut- ism, 15 (26.3%) had Pervasive Developmental Disorder Not Otherwise Specified, and 3 (5.3%) had high- functioning autism. One hour of sleep and/or awake EEG recordings was obtained for each child. All patients were evaluated with respect to clinical and familial characteristics and with the Childhood Aut- ism Rating Scale, the Autism Behavior Checklist, and the Aberrant Behavior Checklist. The frequency of interictal epileptiform EEG abnormalities (IIEAs) was 24.6% (n = 14), and the frequency of epilepsy was 14.2% (n = 8). IIEAs were associated with a diagnosis of epilepsy (P = 0.0001), Childhood Autism Rating Scale Activity scores (P = 0.047), and a history of asthma and allergy (P = 0.044). Epilepsy was associated with a family history of epilepsy (P = 0.049) and psychiatric problems in the mother during pregnancy (P = 0.0026). Future studies with larger samples will help to clarify the possible associations of epi- lepsy/IIEAs with asthma/allergy, hyperactivity, and familial factors in ASD. Ó 2009 Elsevier Inc. All rights reserved. 1. Introduction Autistic spectrum disorders (ASD) are devastating conditions with an onset in early childhood and core symptoms of varying de- grees involving communication and social and cognitive develop- ment, and usually sparing gross motor development. In 1943, Kanner was the first to describe the case of an autistic individual who developed epilepsy [1]. The frequency of epilepsy in autism ranges from 4% to 42% according to different studies [2–6]. It is known that a significant majority of patients with ASD without sei- zures have interictal epileptiform EEG abnormalities (IIEAs) on routine EEG studies [5,6]. The incidence of IIEAs in autistic individ- uals was found to be between 6% and 74% [5,6–8]. Previous studies have reported age, mental status and neurolog- ical findings as risk factors for epilepsy in ASD. There is a bimodal age distribution of seizures in autism: one peak occurs before 5 years of age and the other in adolescence after age 10 [7,9,10]. Individuals with ASD who have profound mental retardation and/ or cerebral palsy are at high risk for epilepsy [5,7]. However, whether there are other factors associated with epilepsy and epi- leptiform EEG abnormalities in ASD remains unknown. Indeed, although not previously shown, the factors associated with epi- lepsy and IIEAs may differ. The aim of this study was to examine the characteristics of EEG findings and epilepsy in ASD subtypes and the association between epilepsy and EEG abnormalities and clinical, psychiatric, developmental, and familial risk factors. 2. Methods Fifty-seven patients between the ages of 2 and 18 years who were diagnosed with ASD (autism, Asperger syndrome, Pervasive Developmental Disorder Not Otherwise Specified [PDD-NOS], high-functioning autism [HFA]) according to DSM-IV [11] criteria were included in the study. For all patients, 1-hour recordings of sleep and/or awake EEGs were obtained. Patients with a diagnosis of schizophrenia, schizophrenic disorder or any other psychotic disorder, Rett syndrome, childhood disintegrative disorder, and severe mental retardation (Total IQ <25) were excluded from the study. The study period was from June 2007 to April 2008. The EEGs were performed in three university hospitals in Istan- bul. However, all of the EEGs were reevaluated blindly by the same pediatric neurologist who has expertise in pediatric epilepsy (U.I.). Electrodes were placed according to the international 10–20 system; 18 electrodes were used and recorded with bipolar and referential 1525-5050/$ - see front matter Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2009.11.014 * Corresponding author. E-mail address: ozalpekinci@yahoo.com (O. Ekinci). Epilepsy & Behavior 17 (2010) 178–182 Contents lists available at ScienceDirect Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh