Epilepsy and autism are both relatively common conditions of the brain and frequently exist together.

Researchers are seeing increasing evidence of a link between these conditions. There is no plausible reason for autism causing epilepsy, however, the co-occurrence of autism and epilepsy is almost certainly because of underlying factors predisposing the person to both conditions, including both genetic and environmental factors.

Autism is more common in people with epilepsy, and epilepsy is more common in people with autism[i]

The figures

• Epilepsy and seizures are more common in people with autism than in the general population. [ii]
• In Australia, approximately 1% of the population have active epilepsy and up to 3.5% of people will develop epilepsy over their lifetime. [iii]
• It is estimated that approximately 1.5% of the population are on the autism spectrum disorder. [iv]

Figures differ greatly for the combination of both conditions, but data from a review of multiple studies showed that:

• The average overall occurrence of epilepsy in people with autism is approximately 12% (range: 1.8-60%).
• The rate of autism in epilepsy further increases in people with intellectual disability. So having an intellectual disability greatly increases the risk of epilepsy in people with autism.[i]

Someone with epilepsy is almost 10 times more likely to be diagnosed with autism than someone in the general population. [vii] While a connection between the two exits, how they influence each other has yet to be identified.

Conditions such as attention deficit hyperactivity disorder, anxiety and sleep disorders are also common in both people with epilepsy and autism.

Overlapping features

There is no doubt some of the features seen with seizures and autism can overlap.  Behaviours or movements seen in some seizures can look like some features of autism, and vice versa, sometimes making it difficult to distinguish between the two.

Overlapping features such as episodic, repetitive behaviours, staring episodes, motor tics and stereotyped movements can be seen in both diagnoses and if they are present, can make it difficult to make a distinction between the subtle signs of seizures and the characteristics of autism. This can make diagnosis challenging.

Even so, it is important to establish if these features are seizures, or other neurological events because it is necessary to treat seizures appropriately. EEG’s can sometimes help capture abnormal electrical activity and assist with the correct diagnosis.

What might explain the link between autism and epilepsy? [ix]

One theory for the overlap is that the conditions share common biological mechanisms.

Epilepsy is characterised by too much excitation in the brain, which may stem from too little inhibition. A landmark study published in 2003 proposed that autism may also stem from an imbalance between excitation and inhibition in the brain. There are data to support this theory from studies in both animals and people, but there is still debate over this theory.

Does one condition cause the other? [i]

From the current evidence, it appears that epilepsy is rarely the cause of features seen in people with autism, although poorly controlled or inadequately treated seizures can cause these features. This can occur in some epilepsy syndromes such as Landau Kleffner, Dravet Syndrome, West Syndrome and Electrical Status Epilepticus of Slow-Wave Sleep (ESES), so it is important to treat seizures promptly and effectively. One challenge in people with autism is to determine why early childhood regression occurs in perhaps 25% of children. Whether epilepsy plays a role in the regression of this subgroup of children with autism who lose skills remains to be determined.

There is no plausible argument for suggesting that autism could cause epilepsy.

It seems that the weight of evidence now favours a common underlying cause for both conditions.

Do epilepsy and autism spectrum disorder share genetic risk factors? [ii]

The co-occurrence of autism spectrum disorder and epilepsy is almost certainly the result of underlying factors predisposing to both conditions, including both genetic and environmental factors. In people with autism and epilepsy, almost half have a genetic cause.

Genetic testing is very important for epilepsy and autism spectrum disorder because it may be helpful for clinicians to determine appropriate management and interventions, treatment, and prognosis.[x]

Environmental factors include maternal health or complications, mental health, medications taken during pregnancy, parental age, gestational age the baby is born, low birth weight, jaundice, and postnatal infection.[xi]

Having a greater understanding of the relationship between these two conditions could have significant effects on their management. If the risk factors for developing epilepsy in people with autism were better understood, perhaps the epilepsy could be prevented in this group, or at least recognised early and managed better, as a result. Good management of autism, epilepsy and comorbidities can greatly improve the quality of life of both the affected person and the family.

If you think you or your child may be on the autism spectrum

Someone on the autism spectrum will have symptoms such as: [xii]

Social communication challenges

Children and adults with autism have difficulty with verbal and non-verbal communication. For example, they may not understand or appropriately use:

• Spoken language (around one third of people with autism are non-verbal)
• Gestures
• Eye contact
• Facial expressions
• Tone of voice
• Expressions not meant to be taken literally

Additional social challenges can include difficulty with:

• Recognising emotions and intentions in others
• Recognising one’s own emotions
• Expressing emotions
• Seeking emotional comfort from others
• Feeling overwhelmed in social situations
• Taking turns in conversation
• Gauging personal space (appropriate distance between people)

Restricted and repetitive behaviours

Restricted and repetitive behaviours vary greatly across the autism spectrum. They can include:

• Repetitive body movements (e.g. rocking, flapping, spinning, running back and forth)
• Repetitive motions with objects (e.g. spinning wheels, shaking sticks, flipping levers)
• Staring at lights or spinning objects
• Ritualistic behaviours (e.g. lining up objects, repeatedly touching objects in a set order)
• Narrow or extreme interests in specific topics
• Need for unvarying routine/resistance to change (e.g. same daily schedule, meal menu, clothes, route to school)

If you or your child have these features you should talk to your GP or child health nurse about it, or any other health professional you or your child see and discuss how to get a further assessment.

The assessment is done by specialists in the field, and it is quite comprehensive and lengthy but waiting times can be very long for a formal autism assessment, so it is best to speak to someone early if you have concerns.

Tips for when you speak to someone

• Write a list of the signs of autism you think you or your child have and bring it with you. Don’t overthink this, they are experts and know what questions to ask
• Ask people who know you or your child well (like friends, family or teachers) for some honest feedback about you/your child’s traits
• Bring someone who knows you well with you if you think it might help

At the end of the assessment, a lengthy report will be drafted to confirm the diagnosis of autism spectrum disorder or other possible diagnoses.

How a diagnosis can help

For parents and children, a diagnosis can help you:

• Understand your child’s needs and how you can help your child
• Get appropriate interventions in place
• Get support for your child at school
• Get financial support for parents and carers
• Understand that your child is not just being “difficult”

For adults, a diagnosis can help you:

• Understand why you might find some things harder than other people
• Explain to others why you see and feel the world in a different way
• Get support at college, university or at work
• Get some financial support to help with therapies if you need them

Seizures in people with autism - 'red flags'

Doctors and caregivers of people with autism should look for the following “red flags” as signs that the person may be having a seizure:

• Short spells of unexplained staring
• Transient involuntary, unusual, or repetitive movements
• Confusion and/or wandering with no apparent cause
• Loss of bladder control
• Changes in abilities or emotions for no clear reason

Poorly controlled or untreated seizures may affect a person's:

• Language and communication skills
• Thinking, memory and reasoning skills
• Behaviour

Anyone who has symptoms of seizures should see a neurologist. A correct diagnosis and treatment may help control the brain activity and prevent seizures.[xiii]

If you have concerns about anything raised in this article, contact Epilepsy Action Australia on 1300 3745 47 or Autism Awareness Australia.

Source: Epilepsy Action Australia

References

[i] BesagF. M. (2017). Epilepsy in patients with autism: links, risks and treatment challenges. Neuropsychiatric disease and treatment, 14, 1–10. https://doi.org/10.2147/NDT.S120509  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739118/

[ii] Lee, B. H., Smith, T., & Paciorkowski, A. R. (2015). Autism spectrum disorder and epilepsy: Disorders with a shared biology. Epilepsy & behavior : E&B, 47, 191–201. https://doi.org/10.1016/j.yebeh.2015.03.017

[iii] EpilepsyAction Australia. Facts and Statistics https://www.epilepsy.org.au/about-epilepsy/facts-and-statistics/ AccessedJan 2022

[iv] Center for Disease Control and Prevention USA. https://www.cdc.gov/ncbddd/autism/new-data.html AccessedJan 2022

[v] https://www.sciencedirect.com/science/article/abs/pii/S1525505019304949

[vi] XianLiu, Xin Sun, Caihong Sun, Mingyang Zou, Yiru Chen, Junping Huang, Lijie Wu,Wen-Xiong Chen. (2021) Prevalence of epilepsy in autism spectrum disorders: A systematic review and meta-analysis

ResearchArticle https://doi.org/10.1177/13623613211045029

[vii] https://www.spectrumnews.org/news/the-link-between-epilepsy-and-autism-explained/ AccessedJan 2022

[viii] https://tacanow.org/family-resources/seizures/ AccessedJan 2022

[ix] https://www.spectrumnews.org/news/the-link-between-epilepsy-and-autism-explained/ AccessedJan 2022

[x] LongShasha, Zhou Hao, Li Shuang, Wang Tianqi, Ma Yu, Li Chunpei, Zhou Yuanfeng,Zhou Shuizhen, Wu Bingbing, Wang Yi. (2019) The Clinical and Genetic Features of Co-occurring Epilepsy and Autism Spectrum Disorder in ChineseChildren. Frontiers in Neurology. Vol 10. Pg. 505.

https://www.frontiersin.org/article/10.3389/fneur.2019.00505

[xi] Karimi,P., Kamali, E., Mousavi, S. M., & Karahmadi, M. (2017). Environmental factors influencing the risk of autism. Journal of research in medical sciences: the official journal of Isfahan University of Medical Sciences, 22, 27. https://doi.org/10.4103/1735-1995.200272

[xii] AutismSpeaks. Symptoms of Autism https://www.autismspeaks.org/what-are-symptoms-autism Accessed Jan 2022

[xiii] https://www.medicalnewstoday.com/articles/260649#contacting-a-doctor Accessed Jan 2022

https://www.autism.org/autism-and-seizures/ Accessed Jan 2022