Recent research has uncovered links between epilepsy and autism. In this article, we will cover some of the studies that have brought scientists to this conclusion, and ask why it might be the case.
Epilepsy and autism are both prevalent and disruptive conditions. Autism is estimated to affect 1 percent of the population, and epilepsy has been calculated to affect 1 in 26 people during their lifetime.
Although the conditions do not seem, at first glance, to have much in common, medical research is slowly uncovering links between the two.
Contents of this article:
Here are some key points about epilepsy and autism. More detail and supporting information is in the main article.
- Epilepsy is more common in individuals with autism than the general population
- Some estimate that more than 15 percent of people with epilepsy have autism traits
- Why the link between autism and epilepsy exists is still unknown
- Some researchers believe that epilepsy medication might ease some symptoms of autism
Epilepsy and autism
Increasing evidence shows that autism and epilepsy are linked.
Epilepsy is a disorder of the brain - it is neurologic. People with epilepsy have seizures when certain brain nerves fire abnormally, causing effects that they have no control over.
The type of epileptic seizures most people are familiar with are the type where an individual loses consciousness, falls to the floor, and experiences uncontrolled movements of their body.
However, this is only one form of seizure that people with epilepsy have. Other symptoms include:
- Absences - loss of consciousness with only minor muscle effects
- Partial seizures - rarely, epilepsy affects only part of the body, and the person remains conscious during the episodes
- Auras - some people experience unusual smells, fears, or anxiety
- Seizures during sleep - some people with epilepsy only have seizures while asleep
- Twitches - such as of the eyes or eyelids
Autism is a disorder of childhood development. It is known as autism spectrum disorder, or ASD for short. Children with ASD start showing problems with social and behavioral progress. There is a range of ASD types, with various behavioral presentations in children.
The main features of any ASD are:
- Poorer social abilities, with less communication or interaction - perhaps, less able to respond to conversation, understand body language, and emotion, or form relationships.
- Interests and activities, or patterns of behavior that are narrower and repetitive - perhaps becoming distressed when a fixed routine is disrupted.
Epilepsy is the result of an abnormality in the brain, and autism probably is, too, with differences in brain structure and function. They are clearly different conditions - but there are overlaps between their features. Could they have biological links?
Research into links between epilepsy and autism
There are many questions about links between epilepsy and autism that are being explored by medical science.
What is certain is that epilepsy is more common in people who have autism, and also that ASD is more common in people who have epilepsy. This link shows in different ways, at various levels of epilepsy and autism.
Some research has found that electrical activity in the brains of people with autism display epilepsy-type discharges more often than in people without ASD.
Other work has shown that adults with epilepsy have more autistic traits than those without epilepsy.
The overlap is two-way: people with epilepsy are more likely to have ASD, and people with ASD are more likely to have epilepsy. The estimates for the amount of overlap are that:
- Autism spectrum disorders could be present in anywhere between 15 percent and almost half of people who have epilepsy
- Between about a fifth and a third of children who have ASD develop epilepsy before becoming adults
Theories of why epilepsy and autism are linked
One review of the current research on the topic looked at various findings about the brain's electrical activity, using EEG.
EEG is often used to diagnose epilepsy. It can record epilepsy seizures, but it can also detect other 'epileptiform (resource no longer available at www.tacanow.org)' electrical activity. These studies have shown clear EEG overlaps between epilepsy and autism.
The review, which was published in the journal Pediatric Research, said that some studies found high rates of epileptiform EEGs with autism, even when there was no diagnosis of epilepsy. Some scientists believe these abnormalities might have something to do with causing autism, but there is still no clear proof. The review itself could not draw solid conclusions about the links.
It could be that the genetic factors behind epilepsy overlap with those behind autism, but research on this is limited.
Although there is much evidence of a link, there are still many questions to answer.
Can epilepsy treatment help with autism?
If epilepsy is linked to autism, could epilepsy medication help autism?
Scientists have also investigated whether treating epilepsy in children who have autism could benefit both epilepsy and autism.
The review authors looking into EEG findings confirmed that diagnosed cases of epilepsy should, of course, be treated. However, for individuals with autism and no epilepsy, but who did show EEG discharges, it was not clear if they should also be treated with epilepsy drugs.
The authors of the review wrote that better research was needed to investigate whether epilepsy drugs could have any overall benefit for individuals with autism. Doctors helping to manage autism will also be wary of trying such treatment until there is good evidence from clinical trials.
SallyAnn Wakeford has done a lot of work into epilepsy and autism. In her 2015 publication, she agreed that more work was needed. She found that:
- People with epilepsy are more likely to display autism traits
- These are worse with longer-term epilepsy
- Traits improve with effective anti-epilepsy drug treatment
But, the autism characteristics in people with epilepsy were limited to traits of social responsiveness. There was no increase in repetitive behaviors with epilepsy, for instance. Wakeford questions whether epilepsy and autism are truly related, or if they just overlap.
What to do about the link between autism and epilepsy
In her review, Wakeford is clear that there is a link between autism and epilepsy, but the reasons are still a mystery:
- It could be indirectly due to epilepsy's impact on social and psychological life
- Or, it could be more direct, with epilepsy involving a "social cognitive dysfunction" - a problem in the brain affecting social thinking and ability
Whether there is a direct link or not, it is important that people with epilepsy or ASD, and their carers and health professionals, should be alert to the other condition.
It is particularly important that epilepsy - as for anyone else - is diagnosed and treated in people with autism.