Overview
A seizure is an episode of neurologic dysfunction caused by abnormal neuronal activity that results in a sudden change in behavior, sensory perception, or motor activity. The clinical spectrum of seizures includes simple and complex focal or partial seizures and generalized seizures.
The term “epilepsy” refers to recurrent, unprovoked seizures from known or unknown causes. The term “ictus” describes the period in which the seizure occurs, and the term “postictal” refers to the period after the seizure has ended but before the patient has returned to his or her baseline mental status.
A focal or partial seizure consists of abnormal neuronal firing that is limited to 1 hemisphere or area of the brain and that manifests itself as seizure activity on 1 side of the body or one extremity. These seizures are classified as simple partial if there is no change in mental status or complex partial if there is some degree of impaired consciousness.
A generalized seizure consists of abnormal electrical activity involving both cerebral hemispheres that causes an alteration in mental status. Traditionally, the patient with 30 minutes of continuous seizure activity or a series of seizures without a return to full consciousness is defined as being in status epilepticus (SE). Newer definitions suggest that SE is defined by duration of 5 continuous minutes of generalized seizure activity or 2 or more separate seizure episodes without return to baseline.
This article focuses on the emergency department (ED) evaluation, management, and disposition of adult patients presenting for evaluation of seizure. Febrile seizures in children are a distinct entity and are discussed in a separate article.