BACKGROUND Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence. METHODOLOGY A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings. RESULTS Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis. CONCLUSION The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.

中文翻译：

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热带神经病学中的盘尾丝虫病：范围综述

背景盘尾丝虫病是热带地区的严重问题。寄生虫作为与神经系统疾病相关的因素的作用需要解决，因为它可能涉及通过消除策略降低风险。我们进行了系统的范围审查，以确定关于这种关联的可用研究，并透视不同的方法论方法来解释证据。方法学 使用 MEDLINE (Pubmed) 进行了截至 2020 年 10 月 1 日的文献检索。我们纳入了所有评估热带国家盘尾丝虫病与四种神经系统疾病（癫痫、点头综合征、Nakalanga 综合征和脑炎）之间关联的研究。对结果进行了描述性和批判性总结，以提供对调查结果的概述。结果 总体而言，文献检索共检索到 161 篇文章。经过全面检查，我们纳入了 12 篇关于癫痫的文章和 3 篇关于点头综合征的文章。对病例对照研究的两项荟萃分析发现，肠扭转与癫痫之间的关联强度适中。最近的荟萃分析和原始研究支持显着关联。流行病学研究表明盘尾丝虫病与点头综合征之间存在关联，但是，病例对照研究的证据水平相对较低。没有报告 Nakalanga 综合征的相关性测量。没有关于 O. volvulus 和脑炎之间关联的具体研究。结论 盘尾丝虫病与癫痫之间的关联似乎越来越有可能。然而，关于这种癫痫的不同临床表现，仍有许多悬而未决的问题。强有力的国际合作对于提高我们对这些有趣疾病的风险因素和病理生理机制的理解至关重要。