1. ILAE Commission for Classification and Terminology

2. Purpose of the International Classification of Seizures and Epilepsies  To provide a common international terminology and classification  Largely for clinical (treatment) purposes  Purpose of classification: to organize items according to their fundamental relationships

3. 2005-2009 Commission Report, Epilepsia 2010;51:676-685

4. Main changes, modifications LLanguage and structure for organizing epilepsies GGeneralized versus Focal Seizures ““Etiology” DDiagnostic specificity NNew recommended terms OOrganization NNO changes to electroclinical syndromes AA diagnosis can be made as previously eg Lennox-Gastaut syndrome, childhood absence epilepsy AA diagnosis is not the same as a classification

5. Focal reconceptualized  For seizures:  Focal epileptic seizures are conceptualized as originating within networks limited to one hemisphere. These may be discretely localized or more widely distributed.…

7. Focal seizures Blume et al, Epilepsia 2001  Without impairment of consciousness or awareness  Previous term: simple partial  With observable motor or autonomic components  eg. focal clonic, autonomic, hemiconvulsive  With subjective sensory or psychic phenomena  Aura - specific types  Where alteration of cognition is major feature  Previous term: complex partial  Dyscognitive

8. Focal seizures Blume et al, Epilepsia 2001  Evolving to bilateral, convulsive seizure  Previous terms: partial seizure secondarily generalized; secondarily generalized tonic-clonic seizure  With tonic, clonic or tonic and clonic components

9. Generalized - reconceptualized  For seizures  Generalized epileptic seizures are conceptualized as originating at some point within, and rapidly engaging, bilaterally distributed networks. …can include cortical and subcortical structures, but not necessarily include the entire cortex.

12. Generalized Seizures Tonic-clonic (in any combination) Absence - Typical - Atypical - Absence with special features Myoclonic absence Eyelid myoclonia Myoclonic - Myoclonic - Myoclonic atonic - Myoclonic tonic Clonic Tonic Atonic Seizure types thought to occur within and result from rapid engagement of bilaterally distributed systems

13. Recommended terminology for etiology Use terms which mean what they say:  Genetic  Structural-Metabolic  Unknown Previously used terms denoting old concepts: Idiopathic, cryptogenic, symptomatic

14. Genetic  Concept: the epilepsy is the direct result of a known or inferred genetic defect(s). Seizures are the core symptom of the disorder.  Evidence: Specific molecular genetic studies (well replicated) or evidence from appropriately designed family studies.  Genetic does not exclude the possibility of environmental factors contributing

15. Structural-Metabolic  Concept: There is a distinct other structural or metabolic condition or disease present.  eg. Tuberous sclerosis  Evidence: Must have demonstrated a substantially increased risk of developing epilepsy in association with the condition.

16. Unknown  Concept: The nature of the underlying cause is as yet unknown.

17. New recommended terminology Previously used terms no longer preferred  Classification as focal or generalized epilepsies  not always appropriate  use when appropriate  Catastrophic - emotionally laden term  Benign - does not recognize that co-morbidities occur, this term is still used in syndrome names Recommended terms  Self-limited: high likelihood of spontaneous remission  Pharmacoresponsive

18. New terminology and concepts update the classification to be consistent with current understanding of the epilepsies in clinical practice Currently there is no biologically based classification of the epilepsies Epilepsies can be organized in a flexible, multidimensional way depending on the purpose eg. by age, etiology, seizure type, EEG abnormality  Future efforts in classification will depend on a biological mechanisms as these are understood Future developments in the Classification of the Epilepsies