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Key Points

  • Always check a bedside glucose level in seizure patients.

  • Monitor airway, breathing, and circulation in actively seizing patients and intervene when needed.

  • Intravenous lorazepam is the drug of choice for actively seizing patients.

  • Search for a secondary cause of seizures in first-time seizure patients and those with a known seizure disorder who have new or different features.


A seizure is an episode of abnormal neurologic function caused by inappropriate, excessive activation of neurons in the brain. Seizures account for up to 2% of emergency department (ED) visits and affect approximately 4 million people in the United States. The incidence of seizures is highest among those <20 and >60 years of age. Status epilepticus is continuous or intermittent seizure activity for more than 5 minutes without recovery of consciousness. It has a mortality rate of up to 20%. Half of all patients presenting to the ED in status epilepticus have no prior history of seizures. ED management of seizures should focus on cessation of seizure activity.

Seizures result from abnormal excitation or lack of inhibition of neurons in the brain. The cause may be primary (idiopathic) or secondary, with an underlying etiology that may be treatable such as hypoglycemia. In patients with a known seizure disorder, the most common cause of recurrent seizures includes medication noncompliance, sleep deprivation, alcohol or substance withdrawal, and infection. Secondary causes of seizures include head trauma, stroke, intracranial infection or mass, electrolyte abnormalities, alcohol withdrawal, drug overdose, and eclampsia.

Seizures are classified as generalized or partial. Generalized seizures are characterized by excitation of the entire cerebral cortex and always cause alteration of mental status. Generalized seizures can manifest as a staring spell (absence or petit mal), diffuse motor activity (tonic-clonic or grand mal), or drop attacks (myoclonic, tonic, clonic, or atonic). The postictal period refers to the time (lasting up to 1 hour) after a generalized seizure when the patient gradually returns to baseline mental status. The postictal period often distinguishes generalized seizures from other causes of sudden altered mental status such as syncope.

Partial seizures are caused by localized neuronal activation that may remain localized or spread to involve other areas of the brain (referred to as partial seizure with secondary generalization). Patients with simple partial seizures experience brief focal motor or sensory symptoms without altered mental status. Complex partial seizures are characterized by altered consciousness with autonomic, sensory, motor, and/or psychological manifestations (Table 83-1).

Table 83-1.

Classification of seizures.

Clinical Presentation


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