Unravelling the mysterious onchocerciasis-nodding syndrome link: new developments and future challenges

Nodding syndrome (NS) is a chronic, progressive, epileptic encephalopathy of undetermined aetiology, affecting primarily children within the select age group of 5–15 years. Some cases having NS-like clinical features have been described in a number of onchocerciasis-endemic African countries (1), however it is in Northern Uganda (2) and Southern Sudan (3) were epidemic proportions have been noted. First described by Louise Jilek-Aall in Tanzania in the 1960s (4), NS core clinical features are the atonic seizures manifesting as repetitive head nodding episodes (5), often occurring in association with taking a meal or by cold weather, and may be trailed or heralded by other seizure types, behavioural difficulties and deteriorating cognitive function (5-7).