Application of the 2001 diagnostic scheme and the 2006 ILAE report of seizure and epilepsy: a feedback from the clinical practice of adult epilepsy

Abstract

Purpose: To clarify the clinical validity and feasibility of the diagnostic scheme for seizures and epilepsy proposed by the International League Against Epilepsy (ILAE) in 2001 (the 2001 Scheme) and the report of the ILAE classification core group in 2006 (the 2006 Report).

Methods: One hundred consecutive patients with epilepsy who visited the Neurology Clinic (Group 1) and 100 patients with intractable epilepsy who had undergone prolonged scalp video-EEG monitoring (Group 2) in Kyoto University Hospital were enrolled. The 2001 Scheme (Axis 1 to 4) and the 2006 Report (seizure types and epileptic syndromes) were applied to Group 1. Axis 1 was applied to Group 2 to evaluate the diversity of seizure semiology.

Results: Group 1 demonstrated 145 seizures of different types (generalized tonic-clonic seizures: 23%, complex partial seizures (CPS): 29%, simple partial seizures: 21% and secondarily generalized tonic-clonic seizures: 21% according to the 1981 classification. In Axis 1 (ictal phenomenology) of the 2001 scheme, 184 and 333 items were listed in Groups 1 and 2, respectively, and seizure semiology was described independent of EEG findings. However, there was duplications or discordance among the items. In Axis 2 (seizure types) of Group 1, 62% and 26% of CPS were further labeled as focal motor or sensory seizures, respectively; the remainder (24%) did not meet inclusion criteria for any category. In Axis 3 (epilepsy syndromes), 94% of patients were sorted, and familial temporal lobe epilepsy was added. Axis 4 described detailed etiology. Application of seizure types of the 2006 Report required consideration of ictal phenomenology to determine spread patterns. Epileptic syndromes of the 2006 Report were assignable to 70% of patients.

Conclusions: It is important to achieve intra- and inter-axial accordance for the establishment of a more practical diagnostic scheme, which may provide a more useful tool for the diagnosis of less obvious aspects of epilepsy.