Incidence Study of Epilepsy using the ILAE 2017 Classification of Epilepsies in a Cohort of School Children Accessing Education in Government Primary Schools in South India.

Background: Recently, the International League Against Epilepsy (ILAE) has proposed new classification schemes for seizures and epilepsy. The applicability of these classification schemes has not been studied in resource-poor countries.

Aim: To determine the incidences of epilepsies in a cohort of school children using the ILAE 2017 classification of epilepsies.

Materials And Methods: The study cohort included 7,408 school going children [age range 5-15 years]. They were followed for new-onset unprovoked seizure and seizure recurrence through first grade to fifth grade. The data collected during the first visit included clinical details including details of seizure semiology. All children had EEG and contrast CT scan. All these data were used to classify seizure type and epilepsy using ILAE classification schemes. The ILAE 2014 epilepsy definition was used to diagnose epilepsy. The average annual incidence rates (AAIR) and 95% confidence intervals (CI) were calculated for epilepsies by onset and by etiology.

Results: The AAIR of epilepsy was 57.85 (95% CI 39.0-82.6) per 100,000 population. The AAIRs per 100,000 for different epilepsies by mode of onset were focal epilepsies 25.07 (95% CI 13.35-42.87); generalized epilepsies 13.5 (95% CI 5.43-27.8); and unknown onset epilepsies 19.28 (95% CI 9.25-35.46). The AAIRs per 100,000 of epilepsies by etiology were focal genetic epilepsies 7.71 (95% CI 2.1-19.75); genetic generalized epilepsies 13.5 (95% CI 5.43-27.8); and epilepsies due to structural cause 17.36 (95% CI 9.25-35.46). The lesional epilepsies seen in this cohort were geographically specific to resource-poor countries. The AAIR of epilepsy due to calcific neurocysticercosis (cNCC) was 9.64 (95% CI 3.1-22.5) per 100,000.

Conclusions: This study demonstrates that the ILAE 2017 classification of epilepsies can be applied in resource-poor countries with limited workup. Lesional epilepsies seen in this study is geographically specific to resource-poor countries.