Classification

Classification systems allow the medical community to communicate with patients and one another in a shared and precise language. They provide a framework within which to explore differences in treatment response and prognosis. Perhaps most importantly, they provide direction for the development of new treatments. The epilepsy community primarily classifies epilepsies according to the ILAE’s International Classification of Epilepsies and Epileptic Syndromes. The ILAE classification distinguishes between generalized epilepsy, in which seizures arise diffusely from the brain, and partial or focal epilepsy, in which seizures arise from discrete parts of the brain.  A natural distinction has arisen within the partial epilepsy class because of differences in the response to surgery. Surgical resection has a high success rate in those with mesial temporal partial epilepsy in which seizures arise from deep within the temporal lobe. Partial epilepsy arising from outside of the deep temporal region, also known as neocortical epilepsy, has received less attention and is less responsive to surgical treatment.  

The ILAE classification system does not include a subclassification for neocortical partial epilepsy.  There is a need for a subclassification system of neocortical epilepsy that allows researchers and clinicians to distinguish between neocortical partial epilepsy patients with different constellations of commonly assessed features of epilepsy.  We are currently applying a novel subclassification system to a group of patients with neocortical partial epilepsy who have not responded to treatment with medication. The subclassification system classifies patients according to the degree to which their epilepsy is focal in four domains: anatomy (neuroimaging), interictal EEG, etiology, and semiology (what the patient experiences during a typical seizure).  We are studying whether the different classes have different outcomes. Are some classes more likely to be referred for pre-surgical evaluation, invasive monitoring, and resective surgery? Are some classes more likely than others to be seizure free after surgery? The answers to these questions may inform decisions about treatments and testing. The subclassification system will improve communication between physicians and patients. It will also be a valuable epidemiologic tool for studying changes in the types of neocortical epilepsies seen over time and in different regions. 

Epilepsy Therapy Project Launches First Comprehensive Epilepsy Pipeline as a Public Resource Identifying an Estimated 80 Product Candidates in Early- to Late-Stage Development