Prevalence and mortality of epilepsies with convulsive and non-convulsive seizures in Kilifi, Kenya

Michael Kazungu,Charles Rjc Newton,Amek Nyaguara,Symon M Kariuki,Rachael Odhiambo,Eddie Chengo,Martha Z Kombe,Brian G Neville,Anthony K Ngugi

doi:10.1016/j.seizure.2021.04.028

Abstract

ObjectivesThe prevalence of all epilepsies (both convulsive and non-convulsive seizures) in Low- and Middle-Income Countries (LMIC), particularly sub-Saharan Africa is unknown. Under estimation of non-convulsive epilepsies in data from these countries may lead to inadequate and sub-optimal allocation of resources to control and prevent epilepsy. We determined the prevalence of all types of epilepsies and compared the mortality between convulsive seizures and non-convulsive seizures in a resource limited rural area in Kenya. MethodsTrained clinicians identified cases of epilepsy in a randomly selected sample of 4,441 residents in the Kilifi Health and Demographic Surveillance System site using a cross-sectional survey design. Seizure types were classified by epileptologists using the current guidelines of the International League Against Epilepsy (ILAE). We estimated prevalence for epilepsy with convulsive seizures and non-convulsive seizures and for epilepsy with non-convulsive seizures only and compared premature mortality between these groups of seizures. ResultsOf the 4441 people visited, 141 had lifetime epilepsy and 96 active epilepsy, which is a crude prevalence of 31.7/1,000 persons (95% CI: 26.6-36.9) and 21.6/1,000 (95% CI: 17.3-25.9), respectively. Both convulsive and non-convulsive seizures occurred in 7% people with epilepsy (PWE), only convulsive seizures in 52% and only non-convulsive seizures in 35% PWE; there was insufficient information to classify epilepsy in the remainder 6%. The age- and sex-adjusted prevalence of lifetime people was 23.5/1,000 (95% CI: 11.0-36.0), with the adjusted prevalence of epilepsy with non-convulsive seizures only estimated at 8.2/1,000 (95%CI:3.9-12.6). The mortality rate in PWE was 6.3/1,000 (95%CI: 3.4-11.8), compared to 2.8/1,000 (2.3-3.3) in those without epilepsy; hazard ratio (HR) =2.31 (1.22-4.39; p=0.011). The annual mortality rate was 11.2/1,000 (95%CI: 5.3-23.4) in PWE with convulsive and non-convulsive seizures and none died in PWE with non-convulsive seizures alone. ConclusionsOur study shows that epilepsy with non-convulsive seizures is common and adds to the prevalence of previously reported estimates of active convulsive epilepsy. Both epilepsy with convulsive seizures and that with non-convulsive seizures should be identified for optimising treatment and for planning resource allocation.

Highlights

Epilepsy is one of the most common chronic neurological disorders and is an important public health problem affecting close to 70 million people worldwide [1]
Most epidemiological studies in Africa have focused on epilepsy with convulsive seizures, since these seizures are easier to detect in crosssectional surveys and are thought to be associated with more morbidity and premature mortality [6]
This study shows that mortality rate was significantly greater in epilepsy than in those without, which is similar to previous studies from this area [6]

Summary

Introduction

Epilepsy is one of the most common chronic neurological disorders and is an important public health problem affecting close to 70 million people worldwide [1] This number approximates about 0.7% of the global burden of disease and contributes up to 17 million disability (http://creativecommons.org/licenses/by/4.0/). Up to 90% of the people with epilepsy (PWE) reside in low and middle income countries (LMICs) [1], with 20% of the global burden in Africa alone [3]. Another 500 million people are affected indirectly as parents, relatives and friends [4]. Neither study estimated the prevalence of life-time epilepsy

Objectives

Methods

Results

Discussion

Conclusion