title: Reviewing the evidence on nodding syndrome, a mysterious tropical disorder.
abstract: OBJECTIVE
  To review the literature on the prevalence, clinical manifestations, pathogenesis, treatment, and implications of nodding syndrome (NS).
  
  
  METHODS
  This is a narrative review.
  
  
  RESULTS
  NS is a mysterious tropical disorder that is emerging in South Sudan, southern Tanzania, and northern Uganda. Over the past decade, thousands of children have become affected, but the prevalence is unknown. NS is characterized by an occasional nodding of the head, which is considered as a form of epilepsy. After symptoms appear, the patient's health rapidly deteriorates. Seizures, stunted growth, and mental retardation may appear. In endemic areas, NS is increasingly becoming a public health problem with high morbidity and mortality, and severe social, psychological, and economic implications. However, the pathogenesis is unknown. Evidence suggests a role for Onchocerca volvulus, the parasitic filarial worm responsible for river blindness, which is highly endemic in these areas. There is no cure for NS, and treatment is symptomatic with common anticonvulsants to improve the quality of life.
  
  
  CONCLUSIONS
  NS seems to be a rapidly growing problem in several eastern African countries. Although it is starting to receive more and more attention in the scientific literature, little is known about NS. A better understanding of the pathogenesis may lead to prevention and treatment opportunities.
authors.affiliation: Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands. d.a.korevaar@amc.uva.nl
authors.forename: Daniël Arnoldus
authors.initials: DA
authors.lastname: Korevaar
authors.forename: Benjamin Jelle
authors.initials: BJ
authors.lastname: Visser
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use; D002648:Child; D004827:Epilepsy / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D019416:Head Movements; D006801:Humans; D017181:Onchocerca volvulus; D009855:Onchocerciasis / Q000150:complications / Q000469:parasitology; D015995:Prevalence; D012640:Seizures / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D013397:Sudan / Q000453:epidemiology; D013577:Syndrome; D013636:Tanzania / Q000453:epidemiology; D014330:Tropical Medicine; D014454:Uganda / Q000453:epidemiology
chemical_list: D000927:Anticonvulsants