Electroencephalography (EEG) alteration in Autism Spectum Disorder (ASD)

Electroencephalography (EEG) alteration in Autism Spectum Disorder (ASD) FLORINA RAD 1, CAMELIA CIOBANU 2, GIANINA ANGHEL 3, IULIANA DOBRESCU 4 ABSTRACT There is a controversial relationship between Autism Spectrum Disorder (ASD) and epilepsy; these two disorders are comorbid in 6.5-10-15% of cases. Some children with ASD have a history of convulsions; others have only changes to the route EEG without clinical expression. There is still controversy concerning the role of epilepsy and epileptiforme discharge in ASD. It is known that they are frequently associated, but their causal link is unclear yet. Objective. The purpose of this paper is to perform a descriptive retrospective analysis of EEG s alteration in a sample of 69 children diagnosed with ASD. Our purpose is to asses the prevalence of EEG alteration in children with ASD, with or without another psychiatric disorder. Method. The clinical sample includes 69 patients, aged between 2 and 6 years old, hospitalized in Child and Adolescent Department, Prof. Dr. Alex. Obregia Hospital of Psychiatry, diagnosed with ASD. The diagnosis was established based on DSM IV TR criteria, using KID-SCID (semistructured interview), NEPSY test (to identify typical and atypical developmental profiles) and Portage Test (to evaluate the developmental level). All EEG were performed in the Hospital s EEG Laboratory and analyzed by a medical doctor specialist in EEG interpretation. We followed the presence of EEG s alteration and we identified the main areas with EEG alteration. We made a descriptive analysis for the variables. Results. 1 MD, Specialist doctor in Child and Adolescent Psychiatry, Child and Adolescent Psychiatry Department, Prof. Dr. Al. Obregia Psychiatry Hospital, Bucharest, Assistant Professor Child and Adolescent Psychiatry Department, University of Medicine and Pharmacy Carol Davila Bucharest 2 MD, resident in Child and Adolescent Psychiatry, Child and Adolescent Psychiatry Department, Prof. Dr. Al. Obregia Hospital of Psychiatry, Bucharest 3 MD, Specialist doctor in Child and Adolescent Psychiatry, Medicover Pediatric Clinic, Bucharest 4 MD, PhD, Primary doctor in Neuropsychiatry, Child and Adolescent Psychiatry Department, Prof. Dr. Al. Obregia Psychiatry Hospital, Bucharest, Professor Child and Adolescent Psychiatry Department, University of Medicine and Pharmacy Carol Davila Bucharest

The clinical sample includes 69 patients, 58 boys and 11 girls 2 to 6 years old. The principal EEG s alterations in our clinical sample were bioelectric immaturity (slow theta/subtheta rhythm) at 45% and the association of bioelectric immaturity and epileptiform activity at 38% from children. The EEG s alterations were identified most frequent in POT (parietal - occipital - temporal) area bilateral: 68%. Conclusions. Discussions. In the clinical sample diagnosed with ASD we identified the following EEG s alteration: convulsive discharge (with clinical correspondent): 4%, bioelectric immaturity (slow theta/subtheta rhythm): 45%, epileptiform activity: 12% and bioelectric immaturity and epileptiform activity: 38%. The main affected area is POT bilateral (68%). Our dates are similar with literature s dates (ASD and epilepsy may be comorbid in 6.5-10-15% of cases). Key words: autism, EEG s alteration, epilepsy REZUMAT Între Tulburarea de Spectru Autist (TSA) şi epilepsie există o relaţie controversată, cele 2 tulburări fiind comorbide în 6,5-10-15% din cazuri. O parte dintre copiii cu TSA au un istoric de convulsii în timp ce la alţii întâlnim doar modificări EEG fără corespondent clinic. Există încă controverse în ceea ce priveşte rolul epilepsiei şi a modificărilor epileptiforme în TSA. Ele sunt frecvent asociate dar legătura lor cauzală nu este încă elucidată. Obiective Scopul acestei lucrări este de a efectua o analiză descriptivă retrospectivă a modificărilor EEG într-un lot clinic de 69 de copii diagnosticaţi cu TSA. Scopul nostru este de a aprecia prevalenţa modificărilor EEG la copiii diagnosticaţi cu TSA cu sau fără alte tulburări comorbide. Metodă Lotul clinic include 69 de pacieţi, cu vârsta cuprinsă între 2 şi 6 ani, internaţi în Clinica de Psihiatrie a Copilului şi Adolescentului, Spitalul Clinic de Psihiatrie Prof. Dr. Alex. Obregia Bucureşti. Diagnosticaţi cu TSA. Diagnosticul a fost stabilit pe baza criteriilor DSM IV-TR, folosind KID-SCID (interviu semistructurat), testul NEPSY (pentru identificarea profilelor tipice şi atipice e dezvoltare) şi Testul Portage (pentru a evalua nivelul de dezvoltare). Toate

înregistrările EEG au fost efectuate în Laboratorul de EEG al Spitalului şi interpretate de un specialist în EEG. Am urmărit prezenţa modificărilor EEG şi am identificat principalele derivaţii în care apar modificări. Am efectuat o analiză descriptivă a vareabilelor. Reultate Principalele modificări EEG identificate în lotul nostru au fost imaturitatea bioelectrică (ritm lent teta/subteta) la 45% din cazuri şi asocierea imaturitate bioelectrică modificări epileptiforme la 38% dintre copii. Principalele derivaţii în care au fost identificate modificările sunt POT (parieto-occipital-temporal) bilateral la 68% din cazuri. Concluzii. Discuţii Principalele modificări EEG identificate la copiii cu TSA sunt: modificări epileptice (cu corespondent clinic) la 4%, imaturitate bioelectrică (ritm lent teta/subteta) la 45%, activitate epileptiformă la 12% şi imaturitate bioelectrică asociată cu activitate epileptiformă la 38%. Aria cerebrală cel mai frecvent implicată este POT bilateral la 68%. Datele obţinute sunt similare cu cele din literatura de specialitate: TSA şi epilepsia sunt asociate în 6,5-10-15% din cazuri. Cuvinte cheie: autism, modificări EEG, epilepsie INTRODUCTION There is a controversial relationship between Autism Spectrum Disorder (ASD) and epilepsy, the two disorders being comorbid in 6.5-10-15% of cases. Some children with ASD have a history of convulsions; others have only changes to the route EEG without clinical expression. There is still controversy concerning the role of epilepsy and epileptiforme discharge in ASD. It is known that they are frequently associated, but their causal link is unclear yet. OBJECTIVE The purpose of this paper is to perform a descriptive retrospective analysis of EEG s alteration in a sample of 69 children diagnosed with ASD. Our purpose is to asses the

prevalence of EEG alteration in children with ASD, with or without another psychiatric disorder. METHOD The clinical sample includes 69 patients, aged between 2 and 6 years old, hospitalized in Child and Adolescent Department, Prof. Dr. Alex. Obregia Hospital of Psychiatry, between 1st of January 2005 to 31 st of December 2006 and diagnosed with ASD. From this sample 48% were diagnosed with pure ASD and the rest of 52% were diagnosed with ASD comorbid with other psychiatric disorders (delay in language development, mental retardation, ADHD, eating disorder and oppositional defiant disorder). The diagnosis was established based on DSM IV TR criteria, using KID-SCID (semistructured interview), NEPSY test (to identify typical and atypical developmental profiles) and Portage Test (to evaluate the developmental level). All EEG were performed in EEG s Laboratory of the Hospital and analyzed by a medical doctor specialist in EEG interpretation. Gender distribution was: 58 boys and 11 girls. The dates were obtained from department s EpiInfo database. We analized the presence of EEG s alteration and we identified the main areas with EEG alteration. The data was statistically processed. We made a descriptive analysis for the variables studied using Excel 2003. RESULTS The clinical trial Gender distribution includes 69 patients, 58 boys and 11 girls with age between 2 and 6 years old (Figure 16% girls 1). 84% boys

Figure 1. Gender distribution We identified the following EEG s alteration in our clinical trial: Group 1 = normal EEG: 1% Group 2 = convulsive discharge (with clinical correspondent): 4% Group 3 = bioelectric immaturity (slow theta/subtheta rhythm): 45% Group 4 = epileptiform activity: 12% Group 5 = bioelectric immaturity and epileptiform activity: 38% (Figure 2). The prevalence of EEG's alteration 38% 1% 4% 12% 45% Normal EEG Convulsive discharge Bioelectric immaturity Epileptiform activity Bioelectric immaturity and epileptiform activity Figure 2. The prevalence of EEG s alteration Depending on the location of EEG s alteration we have identified the following areas with more frequent epileptiform discharge: 1. POT (parietal - occipital - temporal) bilateral: 68% 2. T (temporal) bilateral: 6% 3. Bioccipital: 26% (Figure 3).

The main areas 26% 6% 68% POT bilateral T bilateral Bioccipital Figure 3. Location of EEG s alteration In our clinical trial 48% of children were diagnosed with pure ASD while 52% of cases have a comorbid diagnosis (Figure 4). Comorbid diagnosis 52% 48% Without comorbid diagnosis With comorbid diagnosis Figure 4. Comorbid diagnosis

The main comorbid diagnoses in this sample were: 1. Expressive language delay:11% 2. Mental retardation: 58% 3. ADHD: 25% 4. Eating disorders: 3% 5. Oppositional defiant disorder: 3% (Figure 5). The main comorbid diagnoses 25% 3% 3% 11% 58% Expressive language delay Mental retardation ADHD Eating disorders Oppositional defiant disorder Figure 5. The main comorbid diagnosis Because of comorbid disorders our results are not very specific for ASD. Some of the EEG s alterations are not specific for ASD and we usually come across them in ADHD or in Mental retardation. For this reason we selected from our sample only those children diagnosed with pure ASD, without comorbid disorders. In clinical sample diagnosed with ASD without comorbidities (38 children=48%) we found the following EEG s alteration: Group 1 = normal EEG: 0% Group 2 = convulsive discharge (with clinical correspondent): 9% Group 3 = bioelectric immaturity (slow theta/subtheta rhythm): 40% Group 4 = epileptiform activity: 15% Group 5 = bioelectric immaturity and epileptiform activity: 36% (Figure 6).

EEG s alteration in children with pure ASD 36% 0% 9% 40% 15% Normal EEG Convulsive discharge Bioelectric immaturity Epileptiform activity Bioelectric immaturity and epileptiform activity Figure 6. EEG s alteration in children with pure ASD Depending on the location of EEG s alteration we have identified the following areas with more frequent epileptiform discharge: 4. POT (parietal - occipital - temporal) bilateral: 65% 5. T (temporal) bilateral: 6% 6. Bioccipital: 29% (Figure 7). The main areas 29% 6% 65% POT bilateral T bilateral bioccipital

Figure 7. Location of EEG s alteration CONCLUSIONS. DISCUSSIONS. In the clinical sample diagnosed with ASD we identified the following EEG s alteration: convulsive discharge (with clinical correspondent): 4%, bioelectric immaturity (slow theta/subtheta rhythm): 45%, epileptiform activity: 12% and bioelectric immaturity and epileptiform activity: 38%. The main affected area is POT bilateral (68%). A comorbid diagnosis is present in 52% of cases. The main comorbid diagnoses are ADHD and Mental retardation. Because of comorbid disorders, these results are not very specific for ASD. For this reason we selected from our sample only those children diagnosed with pure ASD, without comorbid disorders. In the clinical trial of children diagnosed with pure ASD we identified the following EEG s alterations: convulsive discharge (with clinical correspondent): 9%, bioelectric immaturity (slow theta/subtheta rhythm): 40%, epileptiform activity: 15% and bioelectric immaturity and epileptiform activity: 36%. Our data are similar with data found in medical research works (ASD and epilepsy may be comorbid in 6.5-10-15% of cases). There are frequent EEG s alterations such as: bioelectric immaturity and epileptiform activity. The main affected area is POT bilateral.