Classification of Seizures

Introduction

In March 2017, the International League Against Epilepsy (ILAE) introduced a new method to categorize seizures, providing doctors with a more accurate means to describe and treat them effectively.

Types of Seizures

Seizures are categorized based on:

• Onset: Where they originate in the brain
• Awareness: Whether or not a person's awareness is affected
• Additional Symptoms: Whether other symptoms, such as movement, are involved

Focal Onset

Focal seizures, previously known as partial seizures, originate in a specific area or network on one side of the brain. They may:

• Start on the brain's surface or deeper areas
• Remain localized or spread to larger areas
• Involve more than one network

Generalised Onset

Generalized seizures affect both sides of the brain or large networks of cells on both sides from the start. They may:

• Impact surface or deeper brain areas
• Not necessarily involve the entire brain, but affect parts of both sides

Unknown Onset

If the beginning of a seizure is unclear, it may be categorized as of unknown onset. As more information becomes available, the type may be reclassified.

Understanding Seizures and Epilepsy

The brain's millions of nerve cells control various functions by transmitting electrical signals. Disruption or excessive signaling can trigger a seizure.

Causes of Seizures

Identifying the cause of seizures can be challenging. Possible causes include:

• Brain damage from birth complications, infections, strokes, or head injuries
• Genetic predisposition
• Other conditions such as tuberous sclerosis
• Unknown factors