Autisim spectrum disorders are series off related conditions such as aspergurs, typical autism or pervasive developmental disorder which is an atypical autism. That share a set of core symptoms of social and comunication deficit such as problems relating to others or interacting in normal social situations. In addition to these core sympotoms we also find other symptoms typclally associated with autism such as poor muscle tone poor motor planning, deficit in motor coordination or even sensory abnormalities. In up to 10% of individual we even see unusual abilities such as memorizastion of trivia or autistic savants. Given that ASD stems from neurodevelopmental problems the fact that we see an association with seizure and epilepsy is not surprising.
Prevalence studies= The number of cases of a disease in a populationN= Measure of sample size= number of people in the study who have ASDWe never had enough studies and for the ones we had were small sample sizes so there’s no really powerful studies/ concrete answer to determine what the prevalence is therefore consider variability exist (to have a lot of data)
This slide illustrates some of the prior prevalence studies that have been done on ASD. As you can see from the information shown here, the studies done have had small sample sizes and display varying prevalence data. For example, the study by Rossi with 60 inpaitients found a 38.3% prevalence whereas the study from Gillberg found closer to 33%. While not wildly different, it does show the challenge is correctly assessing prevalence with small sample sizes.
People withepilepticseizures had other disorders so they concluded that people who have seizures were likely due to comorbidity of other disorders and brain dysfunction besides autism.
Nosology - The branch of medical science dealing with the classification of diseases.
This is just to show you what EEG is and how it works and place the electrode on a persons head
ASD is a neurodevelopmental in origin and seizure is a neurodevelopmental in origin so there might be some sort of common pathway in the brain. However abnormal EEGs w/ ppl with ASD doesn’t mean what kind of ASD they have.There’s not enough data to this date, to classify seizures.
This slide illustrates some of the different waveforms seen on EEG in people with seizures
This pic shows how GABA and glutamate works
Acquired epileptic aphasia - typically develops in healthy children who acutely or progressively lose receptive and expressive language ability coincident with the appearance of paroxysmal electroencephalographic (EEG) changes. In 1957, Landau and Kleffner initially described acquired epileptic aphasia and subsequently reluctantly agreed to the attachment of their names to the syndrome. In this article, acquired epileptic aphasia is used as a synonym for Landau-Kleffner syndrome (LKS). - http://emedicine.medscape.com/article/1176568-overviewSome hypothesized that regression from normal development (up to age 20-24months ) could be related to seizure activity- seizure maybe responsible for regressionin normal development.
We know the there’s a correlation between epilepsy and autistic regression. But we don’t know the cause and effect of it. This is an example of a study that looked at the relationship between epilepsy and autistic regression so that they can establish a cause and effect relationship. Regression at age of less than 3, they are more likely to be male and autistic and regression at greater than 3, are more likely to have seizures.
People who have challenging behavior are associated w/ ASD and have other mental problems ( comorbid psychopathology)Although seizures are a neurological in origin disorders but they can be affected by environment.
Seizures and Epilepsy and Their Relationship to Autism
Seizures and epilepsy and their relationship to autism spectrum disorders Research in Autism Spectrum Disorders 3 (2009) 999–1005 Brian Wells, MPH, MSM
Autism Spectrum Disorders• Autism spectrum disorders (ASD) are five related conditions that all share core symptoms of social and communication deficits as well as rituals and stereotypies• Accompanying these core symptoms are often a host of others problems and disabilities.• Among these difficulties are comorbid psychopathology, challenging behaviors, and other neurodevelopmental disorders such as intellectual disabilities• Given the neurodevelopmental origins of ASD, and the many complicating factors that accompany it, the fact that ASD puts the individual at risk for seizures and epilepsy as well should come as no surprise
Autism Spectrum Disorders• Another concern regarding seizure and epilepsy problems in ASD is simply the large number of persons who display them. Furthermore, these numbers have been increasing in recent years.• Onset of ASD is in early childhood, the numbers are large, and the condition is life long
Autism Spectrum Disorders• Seizures of all types occur in persons with ASD• Two or more seizures of any type (usually within a 3- year period) that are not environmentally induced (e.g., trauma, infection, alcohol withdrawal) are described as epilepsy• Prevalence studies of epilepsy and seizures in general are highly variable for the ASD population. Rates have been reported from 5% to 38%• There have not been many prevalence studies on epilepsy and ASD to date, and most of those have included small sample sizes.• This factor may at least in part account for the fact that considerable variability exists in the current prevalence data.
Autism Spectrum Disorders• Prior studies – Rossi et al. (2000) - 60 inpatients from 12 to 29 years of age with autism. 38.3% of their ASD group evinced seizures/epilepsy. – The 38% figure was also reported by Danielsson, Gillberg, Billstedt, Gillberg, and Olsson (2005) who studied 120 autistic children. – Saemundson, Ludvigsson, Hilmarsdottir, and Rafusson (2007) found seizures in 37% of their 84 autistic child sample – Gabis, Pomeroy, and Andriola (2005) report a co- occurrence of seizures/epilepsy and ASD at 40%. – Gillberg (1987) reported rates of about 1/3 for persons with ASD and seizures/epilepsy. – Finally, on the high end of the seizure/epilepsy and ASD overlap, Oslejskova´ et al. (2008) report a 40% rate.
Autism Spectrum Disorders• A substantial number of studies have concluded that the overlap in seizures and ASD is about 30% of cases or more.• However, a few studies have reported very low overlaps in these problems. – Pavone et al. (2004) reported epilepsy in subgroups with and without comorbid conditions. – Reported 3–55% of the sample by group, with epileptic seizures occurring much more frequently where comorbid disorders were present. – They concluded that seizures were likely due to comorbidity of other disorders and underlying brain dysfunction versus autism.
Nosology• Autistic children with seizures/epilepsy in, general, have lower IQ, less adaptive behavior, more emotional problems, and higher psychiatric drug use.• EEG paroxysmal abnormalities and/or febrile convulsions be used to define the disorder in persons with autism. – In their sample of 106 persons with autism they found the same types of epilepsy seen in the typically developing populations, with idiopathic forms being more common. – Finally, 45% of these individuals first began experiencing seizures after 10 years of age.
Noslogy• Abnormal EEG patterns appear to be a common method of describing seizure and epileptiform activity in persons with ASD• High prevalence of these abnormal EEG and seizures plus the general view that ASD has an underlying neurodevelopmental cause, suggests possible similar neurological pathways across these disorders.• However, abnormal EEGs in ASD do not serve as a means of subtyping ASD• To date, there is a lack of descriptive data on the appearance of seizures in ASD.• Some efforts at looking at EEG patterns have emerged, and it appears that all forms of seizures appear in ASD, although at higher rates than seen in the general population.
Etiology• The general consensus is that ASD is neurodevelopmental in origin. It is further hypothesized that central nervous system dysfunction is neurobiological in origin, thus explaining high rates of abnormal EEG and seizures in ASD• This argument is bolstered by the presence of other central nervous system dysfunctions at higher rates than seen in the general population• One explanation for this overlap of seizures/epilepsy and ASD is an imbalance between excitatory (glutamate) and inhibitory components of neurobiology (gamma aminobutyric acid, GABA).
Austistic Regression• Some have hypothesized that regression from relatively normal development up to age 20–24 months may be related to seizure activity.• It is known that regression in language is associated with seizures or abnormal EEG activity• Up to a third of autistic children may regress• Confusions persist over various definitions of similar disorders to ASD. – Acquired epileptic aphasia and Landau-Kleffner Syndrome (LKS) are often confused with autistic regression due to nonspecific language determination
Autistic Regression• Several authors have proposed a direct link between epilepsy and autistic regression. But, their data is correlational and clear cause and effect relationships are yet to be established. – Shinnar et al. (2001) studied 177 children with language regression. – They concluded that regression earlier than age 3, and being male were most likely to be associated with autism. – Seizures were more common in children over 3 years who regressed but were less likely to be autistic. – Finally, they noted that regression in language was highly correlated to regression in other aspects of functioning such as cognitive and social behavior.
Conclusion• ASD co-occurs with a host of problems such as intellectual disability• Challenging behaviors are often associated with ASD, as is comorbid psychopathology• With respect to seizures, researchers have found that while these disorders are neurological in origin they can be affected by environmental variables and overlapping conditions.• The picture is complex with respect to understanding the causes of the event.• Cause/effect links between seizures and epilepsy to ASD may occur in the future.• At present, much more needs to be learned. Having said that, the clinician should be aware of this high co-occurrence during assessment and intervention.