By: Aliana Gordon
The relationship between autism, or autism spectrum disorder (ASD), and epilepsy have been commonly concurrent with one another, but the link has not yet been proven. More research needs to be conducted to provide a rationale between the two as scientists say they possibly share common pathophysiological properties (1). Sharing prevalent symptoms, such as intellectual disability, related disorders may shed light on the relationship manifesting in different environments.
What is ASD?
Autism spectrum disorder is a developmental disorder that can affect the social, emotional, and communication abilities of a person. As in the name, the spectrum aspect refers to a wide variety of mental disorders that have differing levels of symptoms and disability. The severity of ASD can range where could be fully independent to those who need help in their everyday life with disorders including Asperger syndrome, childhood disintegrative disorder, and unspecified pervasive developmental disorders (2).
Many with ASD show signs in childhood relating to the way they learn, how they react, and their attention. The signs are manifested through social impairment, communication difficulties, and repetitive behaviors. Some examples are (3):
- not showing interest in age-related objects
- have trouble relating to others or not have an interest in other people at all
- avoid eye contact and want to be alone
- have trouble understanding other people’s feelings or talking about their feelings
- appear to be unaware when people talk to them, but respond to other sounds
- Repetitive behaviors
- have trouble adapting when a routine changes
Relationship between Autism and Epilepsy
Compared to the general population, individuals with autism experience seizure disorders at a substantially higher rate. In children with autism of 13 years and older, epilepsy was present in 26% in comparison to the 1% occurring to the general public. Researchers have associated this with the finding that 80% of children with ASD have abnormal EEG results (4). The abnormal electrical surges within the brain could have a correlation to the severity of how autism presents itself in an individual, but more information is needed.
Both ASD and epilepsy have genetic factors that could result in the development of neurological disorders. Autism can be inherited from a parent with the risk of epilepsy in the proband (5). Currently, there are 50 genes and numerous variations that could predispose individuals to autism spectrum disorder (4). With the known association and early speculation from physicians, it has been found that the two conditions are more likely to coexist than to occur individually (1). Although they have an association, there is an unlikely chance that there is one pathophysiological reason for the occurrence.
Studies have been conducted examining tuberous sclerosis complex (TSC) as it is a paradigm. TSC is a rare genetic disease resulting in benign tumors growing on vital organs, affecting the central nervous system resulting in seizure activity in early development. The early onset seizures have been associated with a high risk of ASD as the individual develops. In TSC, 75%-100% of patients with ASD have a co-occurrence with seizures, where seizures occur independently for 70%-80% and ASD occurs independently for 25%-50% of patients (6). Supporting evidence has shown that early treatment for epilepsy has reduced the risk of ASD in TSC but has not erased the risk of development.
With no definitive correlation, there is no specific treatment to cover both conditions. It is currently being treated as an individual with seizures unless it is present in other syndromes such as Landaur-Kleffner Syndrome, Rett syndrome, and Angelman syndrome. The dominant type of epilepsy associated with autism is generalized tonic-clonic seizures. This kind of seizure is characterized by widespread abnormal electrical surges that cause the individual to have muscle contractions and to lose consciousness (7). To reduce the occurrence of seizures, medication is often prescribed along with a change in diet.
- Buckley AW, Holmes GL. Epilepsy and Autism. Cold Spring Harbor Perspectives in Medicine. 2016;6(4):a022749. doi:10.1101/cshperspect.a022749
- Autism Spectrum Disorder Fact Sheet | National Institute of Neurological Disorders and Stroke. Nih.gov. Published 2021. Accessed July 29, 2021. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Autism-Spectrum-Disorder-Fact-Sheet
- CDC. What is Autism Spectrum Disorder? Centers for Disease Control and Prevention. Published March 25, 2020. Accessed July 29, 2021. https://www.cdc.gov/ncbddd/autism/facts.html
- autismAdmin. Autism and Seizures. Autism Research Institute. Published September 8, 2020. Accessed July 18, 2021. https://www.autism.org/autism-and-seizures/
- Bolton PF, Carcani-Rathwell I, Hutton J, Goode S, Howlin P, Rutter M. Epilepsy in autism: features and correlates. Br J Psychiatry. 2011;198(4):289-294. doi:10.1192/bjp.bp.109.076877
- Tuberous Sclerosis Fact Sheet | National Institute of Neurological Disorders and Stroke. Nih.gov. Published 2021. Accessed July 27, 2021. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Tuberous-Sclerosis-Fact-Sheet
- Generalized tonic-clonic seizure: MedlinePlus Medical Encyclopedia. Medlineplus.gov. Published 2016. Accessed July 29, 2021. https://medlineplus.gov/ency/article/000695.htm