Comparing two classification schemes for seizures and epilepsy in rural China

Abstract

Background and purpose The International League against Epilepsy (ILAE) updated the classifications of seizures and epilepsies in 2017. The 2017 classifications were compared with the 1980s classifications in rural China. Methods People with epilepsy receiving treatment under the National Epilepsy Control Programme were recruited from rural areas in China. Their seizures and epileptic syndrome were classified using the 1980s ILAE classification system and then re‐classified according to the 2017 system. Differences in seizure, epilepsy and aetiology classifications were identified. Results A total of 597 individuals (58% males, aged 6–78 years) were included. Amongst them 535 (90%) had a single seizure type, 57 (9.55%) had two types and five (0.84%) had three. There was complete agreement between the 1981 and 2017 classifications for the 525 individuals with focal seizures. Seizures originally classified as generalized in 10 of 65 individuals were re‐classified as unknown in the 2017 classification. Compared to the 1980s classifications, the proportion of individuals with unknown seizures and unknown epilepsy increased from 1.2% (7/597) to 2.8% (17/597, P = 0.002), and unknown aetiology increased from 32% (189/597: 182 cryptogenic and seven unclassified) to 39% (230/597; P < 0.001) in the 2017 classifications. Conclusions The 1980s and 2017 classifications had 100% agreement in classifying focal seizures and epilepsy in rural China. A small but significant proportion of generalized seizures and epilepsy and aetiologies classified in the old classifications were re‐classified to unknown in the new classifications. These results highlight the need for improvement in clinical evaluation of people with epilepsy in resource‐poor settings.

Prevalence of MRI abnormalities in people with epilepsy in rural China

“…The median age at entry was 38 years (interquartile range [IQR] 27-48), median age of epilepsy onset was 14 years (IQR 6-25) and median duration of epilepsy was 19 years (IQR 11-28). As previously described 9 , 525 (88%) individuals had focal epilepsy, 54 (9.1%) had generalized, 1 (0.17%) had combined, and 17 (2.9%) had unknown classification. At recruitment, 524 (88%) were taking anti-seizure medications (ASMs) and additional 46 (7.7%) individuals had been previously treated with ASMs (median number of total ASMs tried 2, IQR 1-3).…”

“…As previously described 9 , predesigned epilepsy history and seizure classification questionnaires were used to collect medical history and seizure information from participants or their carers by primary care physicians. The clinical questionnaire consisted of 19 points covering birth, developmental, family, epilepsy, other medical and drug history.…”

Evaluation of the International League Against Epilepsy 1981, 1989, and 2017 classifications of seizure semiology and etiology in a population‐based cohort of children and adults with epilepsy

“…The distribution of individual seizure types did not differ between ILAE-1981 and ILAE-2017, perhaps because only terminologies changed. Similar to other epilepsy studies, [20][21][22] focal seizures were the most common in all age groups, for both classification systems, asserting that most epilepsy in this area is symptomatic or has identifiable causes, but underlying causes can be identifiable, eg, through neuroimaging. 3 More than half of persons with epilepsy had a seizure onset at the age of 5 years and below, a period when many risk factors for epilepsy, eg, malaria, are common.…”

Classifying epilepsy pragmatically: Past, present, and future

“…Several population and facility-based studies have examined the yield of the syndromic classification. In these studies ( Table 2 ), syndromes were unambiguously assigned in 4–97% of cases [ 29 – 35 ]. The variation represents the differences between samples assessed, methodologies used and experts’ experience [ 36 – 38 ].…”