Onchocerciasis-associated epilepsy: From recent epidemiological and clinical findings to policy implications.

Robert Colebunders,Nolbert Gumisiriza,Alfred K Njamnshi,Marieke Van Oijen,Deby Mukendi,Pierre‐Marie Preux,Richard Idro,Patrick Suykerbuyk,Michel Mandro,Jean Marie Kashama

doi:10.1002/epi4.12054

Abstract

SummaryA high prevalence of epilepsy is reported in many onchocerciasis‐endemic regions. In this paper we discuss recent epidemiological and clinical aspects as well as public health implications of onchocerciasis‐associated epilepsy (OAE) and propose a strategy to reduce the burden of disease. OAE probably presents in a variety of clinical manifestations, including the nodding syndrome and the Nakalanga syndrome. The most common clinical presentation, however, is generalized (primarily tonic‐clonic) seizures. A characteristic of OAE is the onset of seizures between the ages of 3 and 18 years and clustering in certain families and villages close to rapid‐flowing black‐fly‐infested rivers. A strategy combining active surveillance for epilepsy with early treatment with antiepileptic drugs and prevention of onchocerciasis by increasing the geographical and therapeutic coverage of community‐directed treatment with ivermectin (CDTi) may considerably decrease the burden of disease.

Highlights

An estimated 70 million people in the world are affected by epilepsy, with about 2.4 million people diagnosed each
A meta-analysis of African population-based surveys showed a variation in epilepsy prevalence consistent with onchocerciasis prevalence, with epilepsy prevalence being increased, on average, by 0.4% for each 10% increase in onchocerciasis prevalence.[13]
Proposed clinical case definitions for onchocerciasis-associated epilepsy (OAE), nodding syndrome (NS), and Nakalanga syndrome are as follows: OAE* 1 Person with epilepsy living in an onchocerciasis-endemic region 2 Onset of epilepsy between the ages of 3 and 18 years 3 Geographical clustering of persons with epilepsy in the village, or brother or sister with epilepsy 4 No obvious cause for the epilepsy** 5 Normal neurological development before the onset of epilepsy NS = OAE + nodding of the head with episodes of decreased responsiveness Nakalanga syndrome = OAE + important growth retardation and delay or no development of external signs of sexual development without an obvious cause for the growth retardation

Summary

SUMMARY

In this paper we discuss recent epidemiological and clinical aspects as well as public health implications of onchocerciasis-associated epilepsy (OAE) and propose a strategy to reduce the burden of disease. Year.[1,2] Epilepsy prevalence varies largely among continents and countries, with a considerably higher prevalence in populations in low- and middle-income countries.[2,3] Birth trauma, traumatic brain injury, cerebral vascular disease, brain tumors and bacterial brain infections are wellknown causes, but parasitic infections, such as cerebral malaria, neurocysticercosis, echinococcosis, and onchocerciasis, are known to be associated with epilepsy.[3] In this paper we discuss epidemiological and clinical aspects as well as public health implications of onchocerciasisassociated epilepsy (OAE) and propose a strategy to reduce the burden of disease. The adult female worms form subcutaneous nodules and release thousands of microfilariae daily, leading to itching, dermatitis, blindness (all well-known complications of onchocerciasis),[5] and epilepsy.[6]

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Conclusion