Relation Between ILAE Hippocampal Sclerosis Classification and Clinical Findings in Temporal Lobe Epilepsy

To investigate the relationship between clinical features and prognosis of the hippocampal sclerosis (HS) cases and International League Against Epilepsy (ILAE) histopathology classification.

A hundred patients with refractory epilepsy who were operated with the diagnosis of the Mesial Temporal Lobe Epilepsy were included in the study. Socio-demographic characteristics, clinical and family histories, post-operative ILAE and Engel epilepsy scores and diagnostic tests were recorded. At the same time, all of the pathological specimens were classified according to the new semi-quantitative ILAE classification. A significant statistical relationship was investigated between clinical data and HS-ILAE groups.

There were 36 male 64 female patients. The mean follow-up period was 6.5 years. 75% of the cases were HS-ILAE type 1, 19% HS-ILAE type 2, 6% were unidentifiable. FCD3A was detected in 3 patients. The HS-ILAE Type 2 ratio was high on the rightsided cases. In addition, HS-ILAE Type 1 ratio was high in patients with early seizure onset and long duration of epilepsy. There was no significant relationship between long-term ILAE and Engel epilepsy outcome scores and HS-ILAE types.

Resection of mesiotemporal structures in hippocampal sclerosis provides seizure control in at least two-thirds of cases. Histopathological findings may help us understand the epileptogenicity-prognosis of HS. The relationship between ILAE histopathology classification and clinical factors will become more obvious in the future. According to our study, there was a relationship between onset age of epilepsy, epilepsy duration, lesion side and HS-ILAE types. The reinforcement of these relationships with larger series will benefit clinicians.