Autism Spectrum Disorder and Epilepsy / How Common?

epilepsy / a neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain.


Helio Pediatric Annals

Children with Autism Spectrum Disorder and Epilepsy (click for full article)

Amy Francis, DO; Michael Msall, MD; Emily Obringer, MD; Kent Kelley, MD

Autism and Epilepsy

There is much controversy about the interplay between autism and epilepsy. To better understand this linkage, a review of terminology is imperative.

A seizure is characterized as a transient abnormal, excessive, disorderly discharge of neurons primarily in the cerebral cortex.11 Clinically, seizures are paroxysmal, stereotyped, brief interruptions of behavior associated with electrographic seizure patterns.12

Nonconvulsive or subclinical seizures yield EEG abnormalities without clinically recognizable cognitive, behavioral, or motor patterns, or discernible loss of consciousness. Inter-ictal epileptiform activity is paroxysmal electrographic activity containing spike or sharp waves that interrupt the background.12

Epilepsy is defined as two or more unprovoked seizures of any type: generalized, focal, or unknown in origin.11 Therefore, febrile seizures and seizures resulting from acute illness, trauma, infection, or metabolic disturbances are not considered epilepsy. Epilepsy is further classified as electroclinical syndromes, nonsyndromic epilepsies with structural-metabolic causes, and epilepsies of unknown cause.11The clinical diagnosis of seizures in children with autism can be challenging.

Children with autism have many other behaviors that are not epileptic; therefore, video EEG is recommended to confirm that these behaviors are indeed epileptic. Many children display restricted and repetitive patterns of behaviors such as visual perspectiving (?) and these, usually described as “staring episodes” by parents, can mimic absence seizures. Stereotypies are rigid heterogeneous behaviors that are inflexible and nonfunctional in nature, simple or complex, and are reported in 37% to 95% of individuals with ASD.13 They may include arm flapping, hand-finger mannerisms, body rocking, sniffing, or facial grimacing and occur without interruption of consciousness. They are often interpreted by caregivers as seizures. Note that in a report of 15 children with autism referred for seizure evaluation, none of the events recorded were epileptic seizures; however, 73% had EEG abnormalities.14

Seizure types associated with autism depend on age and etiology, and all seizure types have been reported. In one study, the most common type of clinical seizure reported in children with idiopathic autism was complex partial seizures typical of rolandic epilepsy.15 Other studies have reported that generalized tonic-clonic and atypical absence seizures were most common.16 Myoclonic and tonic-clonic seizures have also been reported.17 The overall incidence of epilepsy in children with ASD increases as the child ages.18 (Figure 1).

Figure 1. Relationship between incidence of idiopathic autism and epilepsy. EEG = electroencephalogram. Image courtesy of Amy Francis, DO. Note two peaks of seizure onset.

Many researchers studying the association of autism and epilepsy tend to divide patients into three groups: 1. patients without clinical seizures and EEG paroxysmal abnormalities, 2. patients with EEG paroxysmal abnormalities but no clinical seizures, and 3. patients with epilepsy.10,16 The second and third groups are more likely to have cerebral lesions and autistic regression. The occurrence of severe/profound mental retardation was also more frequent in the third group.

Epidemiology of ASD

The lifetime co-occurrence of epilepsy and ASD is extremely variable and ranges from 5% to 46%.4 The prevalence of epilepsy in children with ASD is between 7% to 14%, and the cumulative prevalence by adulthood ranges from 20% to 35%7 (Figure 1).

Even with conservative estimates, these prevalence rates are substantially higher than in the general population, and are the basis for confirming that ASD is a risk factor for the development of epilepsy.4 There appears to be a bimodal incidence of epilepsy, although not clearly defined, with one peak occurring in the preschool years (younger than 5 years) and a second peak in adolescence (older than 10 years).5 (Figure 1)

For individuals with ASD and intellectual disability, prevalence rates of epilepsy of up to 21% have been reported and are 2.6 times more likely than for those children with ASD but without intellectual disability.8 Among children with ASD and severe intellectual disability (IQ < 55), the average age of seizure onset is 3.5 years. For those with mild intellectual disability (IQ 55–69), the average age of seizure onset is 7.2 years.8 Prevalence is related to both etiology and severity, and epilepsy is more prevalent in children with autism combined with cerebral palsy (27%) and cerebral palsy plus severe mental retardation (67%) than in those without.9 Syndromic autism and severe intellectual disability also occurred more often in individuals with epilepsy.10

Much, much more including MRI and EEG info: Please read full article….

Note that the “Conclusion” boils down to SEE A PEDIATRICIAN who can establish a PHYSICAL BASELINE for your specific child. If your pediatrician doesn’t understand or deal with “brain issues” get a different doctor or see a specialist: the money you spend now is likely MINISCULE compared to what you will spend if you seek diagnosis from a psychologist first (psychologists are not medical doctors, psychiatrists are). Psychologists do not deal with the “physical reality” that all behavior arises from our PHYSICAL BRAIN-BODY; they work from “theories” that are not proven, nor can be proven by use of the scientific method.   


Epilepsy is common in children and young adults with autism, but the relationship is complicated and controversial. (Hint: Turf wars) Though epilepsy is considered to be a negative prognostic factor (poor outcome) for children with autism, advances in understanding specific genetic pathways underlying seizures and autism hold the promise of new treatments and improved long-term outcomes. Concurrent epilepsy and autism are strongly associated with lower cognitive and adaptive behavior levels. Remission rate of epilepsy in children with autism and intellectual disability is only 16%.8 Adults with epilepsy, autism, and intellectual disability experience lower adaptive functioning and encounter more barriers as they transition from pediatric to adult medical care.

Children with autism and seizures represent a unique group of children with special health care needs, and it is important for the general pediatrician to establish a medical home for this population. Early diagnosis and ongoing care coordination is necessary. Ensuring early intervention services, coordinating pediatric subspecialty referrals, managing medications, encouraging an appropriate educational experience, supporting parents, and planning for transition are key elements in providing a medical home for children with autism and seizures.

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