====== ILAE Classification of the Epilepsies ======

The [[International League Against Epilepsy]] (ILAE) [[2017]] [[classification]] provides a [[comprehensive]] [[framework]] for classifying [[seizure]] types and epilepsy syndromes. It improves upon previous classifications by incorporating newer understandings of seizure semiology, electroclinical features, and etiology.

1. Classification of Seizure Types (ILAE 2017)
Seizures are classified based on three key descriptors:

Onset (Where the seizure begins in the brain)
Level of awareness
Motor or non-motor features
A. Focal Onset Seizures (Originates in one hemisphere)
Focal aware seizure: Consciousness is intact.
Focal impaired awareness seizure: Consciousness is impaired.
Motor onset: Includes automatisms, atonic, clonic, epileptic spasms, hyperkinetic, myoclonic, or tonic movements.
Non-motor onset: Includes autonomic, behavior arrest, cognitive, emotional, or sensory symptoms.
Can evolve into a focal to bilateral tonic-clonic seizure.
B. Generalized Onset Seizures (Originates in both hemispheres)
Motor seizures: Includes tonic-clonic, clonic, tonic, myoclonic, myoclonic-tonic-clonic, myoclonic-atonic, atonic, or epileptic spasms.
Non-motor seizures (Absence seizures): Includes typical, atypical, myoclonic, and eyelid myoclonia.
C. Unknown Onset Seizures
Used when the onset is not observed or unclear.
Can be motor (e.g., tonic-clonic, epileptic spasms) or non-motor (behavior arrest).
2. Classification of Epilepsy Types
Epilepsy is categorized into four main types:

Focal epilepsy (previously called partial epilepsy)
Generalized epilepsy
Combined generalized and focal epilepsy
Unknown epilepsy (if the classification is unclear)
3. Classification of Epilepsy Syndromes
Some patients can be diagnosed with specific epilepsy syndromes (e.g., childhood absence epilepsy, juvenile myoclonic epilepsy, Dravet syndrome, Lennox-Gastaut syndrome, etc.).

4. Etiology of Epilepsy
Epilepsy is classified based on its underlying cause:

Structural (e.g., cortical dysplasia, stroke, trauma)
Genetic (e.g., Dravet syndrome, SCN1A mutation)
Infectious (e.g., neurocysticercosis, viral encephalitis)
Metabolic (e.g., mitochondrial disorders)
Immune (e.g., autoimmune encephalitis)
Unknown (when no cause is identified)
Key Improvements in ILAE 2017 Classification
Greater emphasis on focal vs. generalized onset rather than simply classifying based on loss of consciousness.
Introduction of new seizure types such as focal behavior arrest seizures and myoclonic-atonic seizures.
Recognition of combined generalized and focal epilepsy as a separate category.
Emphasis on identifying epilepsy etiology to guide management and treatment.