Epilepsy is a common condition in the population of people with intellectual disability and for many proves intractable. Over the last 20 years a host of new antiseizure medications (antiepileptics) have been introduced to the market, and the evidence base to support their use in people with intellectual disability is reviewed. This will aim to cover new treatment approaches such as cannabinoid preparations succinctly.

There are an estimated 150,000 new cases of epilepsy per year in the United States, with prevalence rates of 7–8 per 1,000 persons. These data, combined with the large number of patients who have seizures from nonepileptic causes, indicate that seizure occurrence is relatively frequent and can result from diverse causes. Although many patients who have a seizure do not need emergency department (ED) care, some present to the ED critically ill and require immediate, definitive management. Advances in the understanding of seizure types and use of new antiseizure medications have enhanced the emergency physician’s ability to diagnose the cause of a patient’s seizures accurately and to treat both the underlying abnormality and the seizures in a rational and systematic fashion.