How common are seizures among people with autism, and what can help?
Back by popular demand: The “Got Questions?” feature of the Autism Speaks Science blog. Today’s answer comes from…
Seizures are indeed more common in both children and adults on the autism spectrum. Independently, autism and epilepsy (seizures of unknown cause), each occur in around 1 percent of the general population. But epilepsy rates among those with autism spectrum disorders (ASD), range from 20 to 40 percent, with the highest rates among those most severely impaired by autism. Conversely, about 5 percent of children who develop epilepsy in childhood go on to develop autism.
Autism and epilepsy share many similarities. Both exist on a spectrum—that is, the severity varies widely among those affected. In addition, a number of different abnormal genes are associated with increased risk of developing one or both disorders.
Importantly to families of children affected by both autism and epilepsy, we know that the combination is often associated with overall poor health and premature death. So development of effective therapies is critically important. This goal begins with increasing our understanding of the shared brain networks, genes, and other biological mechanisms that underlie these two conditions. Autism Speaks is currently partnering with the International League against Epilepsy and Citizens United for Research in Epilepsy to further this research.
At present the treatment of epilepsy in children with autism is based on the same principles as treatment of epilepsy in any child. Should parents suspect that their child is suffering seizures, the first step is to work with a pediatric neurologist to obtain a brain study called an electroencephalogram (EEG), which can determine if these events are indeed seizures. Treatment usually involves an antiepileptic drugs, which the treating physician chooses based on the type of seizure and the associated EEG patterns—to both maximize effectiveness and minimize side effects. By themselves, anti-epileptic drugs fail to resolve seizures in around a third of patients. Such difficult-to-control cases sometimes respond to a so-called ketogenic diet (high-fat, adequate-protein, low-carbohydrate) and/or brain surgery.
Autism Speaks has more information on autism and epilepsy here. Got another question for our scientists and clinicians? Please post it in the comment section.