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Types of Generalized Seizures

Generalized seizures begin with widespread manifestations caused by widespread electrical dysfunction of the entire cortex. Types of generalized seizures in children include:
  • Absence seizures (as seen in Childhood Absence Epilepsy appear as a sudden impairment in consciousness and are associated with eye blinking, staring, and other minor facial movements. There is an abrupt interruption of preceding activities (talking, eating, or walking), but the child does not fall down or have a convulsion. Absence seizures may last from a few seconds to a minute and typically occur multiple times per day with abrupt onset/termination and minimal, if any, post-ictal manifestations.
  • Atypical absence seizures are most common in Lennox-Gastaut Syndrome and other epilepsy syndromes. Atypical absence seizures have gradual onset and termination, cyclic frequency, and are more prolonged or pronounced than typical absence seizures.
  • Myoclonic seizures are lightning-quick limb or body jerks, either unilateral or bilateral, usually without impairment of consciousness.
  • Tonic seizures are episodes of increased muscle tone (spasm) of truncal and facial muscles associated with flexion of upper extremities and extension of lower extremities. They are most common in childhood and may result in falls.
  • Clonic seizures are common in children and may resemble myoclonus except for a loss of consciousness, a slower repetition rate, and the seizures are usually longer.
  • Tonic-clonic seizures generally involve tonic posturing followed by clonic activity typically with sudden onset of increased truncal tone that causes the patient to cry out with forced expiration. They are usually accompanied by a marked increase in heart rate and blood pressure. Incontinence after the spells, as sphincter muscles relax, and post-ictal impairment of consciousness are common.
  • Atonic seizures (also called "drop attacks") result in a sudden loss of all muscle tone, causing the patient to fall to the ground, often with injury.

Authors & Reviewers

Initial publication: March 2013; last update/revision: January 2019
Current Authors and Reviewers:
Author: Lynne M. Kerr, MD, PhD
Authoring history
2013: first version: Lynne M. Kerr, MD, PhDA; Matthew Sweney, MDA
AAuthor; CAContributing Author; SASenior Author; RReviewer