As 20 to 30 percent of children with autism will develop epilepsy, and 15 to 20 percent of individuals with epilepsy are autistic, it has been suggested that there is a link between the two conditions. A recent study has further strengthened that connection by finding that individuals who have a relative with epilepsy may be at an increased risk of being autistic themselves.
Autism is a spectrum of disorders which are characterized by difficulties communicating and interacting with other people. At first glance, the condition seems completely unrelated to epilepsy – a disease in which increased electrical activity in the brain leads to whole-body seizures – but a link between the two has been well-established.
While it’s unknown why this connection exists, researchers from Sweden decided to further investigate the link between epilepsy and autism. The results of their research were published in the journal, Neurology.
“Other studies have linked the two conditions, however, our study looks specifically at the brothers and sisters and sons and daughters of people with epilepsy to determine a possible autism risk in these relatives,” said primary study author Dr. Heléne E.K. Sundelin, from the Department of Pediatrics (H.E.K.S.), University Hospital, Linköping.
By accessing a data registry known as the Swedish Patient Register, the researchers identified 85,201 individuals with epilepsy. Sundelin and colleagues also studied 80,511 siblings of the epileptic patients, along with their combined 98,534 children.
The study investigators compared each epileptic patient’s data to that of five non-epileptic individuals of the same sex, age and country of origin. The siblings of the people with epilepsy were compared to siblings and children of people who did not have the disorder.
During the six-year study period, 1,381 of the epileptic individuals were diagnosed with autism. This is compared to 700 of the non-epileptic patients who were also diagnosed with the condition.
The researchers concluded that individuals with epilepsy have a 1.6 percent risk of being diagnosed with autism, compared to the 0.2 percent risk for the general population. What’s more, those diagnosed with epilepsy in childhood faced a 5.2 percent risk of autism later in life.
Siblings and offspring of people with epilepsy were found to have a 63 percent greater risk of developing autism. Children of mother’s with epilepsy had the greatest risk of autism at 91 percent, while offspring of epileptic fathers had a 38 percent increased risk.
“The goal is to find out more about how these two diseases may be linked so that treatments may be developed that will target both conditions,” said Sundelin. While the true cause of both conditions is unknown, some believe that autism and epilepsy share a genetic basis.