• “A seizure is an episode of abnormal neurologic function caused by an inappropriate electrical discharge of brain neurons.”
  • “Epilepsy is a clinical condition which an individual is subject to recurrent seizures.”
  • “Primary (or idiopathic seizures) are those in which no evidence caused can be identified.”
  • “Secondary (or symptomatic seizures) are a consequence of an identifiable neurologic condition, such as a mass lesion, previous head injury, or stroke.”


The differential diagnosis of seizures includes syncope, pseudoseizures, hyperventilation syndrome, movement disorders, and migraine to name a few. These can be considered “seizure mimics” and should always be kept in mind when working up your seizure patient. 


Seizures are classified into “generalized” and “partial” seizures.

  • GENERALIZED seizures:
    • “Generalized seizures are thought to be caused by nearly simultaneous activation of the entire cerebral cortex, perhaps caused by electrical discharge originating deep in the brain and spraying outward.
      • The attacks begin with abrupt loss of consciousness.
    • Generalized tonic clonic seizures (grand-mal) are the most familiar and dramatic of the generalized seizures. They begin with the abrupt loss of consciousness without warning or aura.
      • In a typical attack, the patient suddenly becomes rigid, trunk and extremities are extended, and the patient falls to the ground.
    • Absence seizures (petit-mal) are very brief, generally lasting only a few seconds. Patients suddenly lose consciousness without losing postural tone.
      • They appear confused, detached, or withdrawn, and current activity seizes.”2


  • PARTIAL (Focal) seizures:
    • “Partial seizures are due to electrical discharges beginning in a localized region of the cerebral cortex. The discharge may remain localized from a spread to involve nearby cortical regions or the entire cortex.
    • In simple partial focal seizures, the seizure remains localized, and consciousness and mentation are not affected.
    • Complex partial seizures are focal seizures in which consciousness or meditation is affected.
      • Symptoms may include automatisms, visceral symptoms, hallucinations, memory disturbances, distorted perception, and affective disorders.”2



Status Epilepticus

Status epilepticus is continuous or intermittent seizures for more than 5 minutes without recovery of consciousness. Treatment for status epilepticus should be initiated in all patients with continuous seizure activity lasting more than 5 minutes.”2


Click HERE for a list of all mentioned FOAM resources.


  1. Kornegay, J., Chapter 171, “Seizures”. Tintinalli’s Emergency Medicine – A Comprehensive Study Guide. J Tintinalli. 8th ed. McGraw-Hill Education, 2016.
  2. Lung, D., Catlett, C., Tintinalli, J., Chapter 165, “Seizures and Status Epilepticus”. Tintinalli’s Emergency Medicine – A Comprehensive Study Guide. J Tintinalli. 7th ed. McGraw-Hill Education, 2010.


Prepared by Alex Mungham PGY1 FM – University of Ottawa