Editorial
According to a joint report by the UN’s Food and Agriculture Organization and WHO, Research priorities for helminth infections, neurocysticercosis is the most important preventable cause of epilepsy with an estimated 2 million people having epilepsy, in the developing world. It is caused by the pork tapeworm Taenia solium, belonging to cyclophyllid cestodes in the family of Taeniidae. The larval or cysticercus stage of this intestinal zoonotic parasite can infect human beings as well as pigs, and if the infection reaches the brain, can cause a wide range of debilitating neurological problems. Despite the huge social costs and global effects associated with neurocysticercosis, roughly 50 million people in the world have the infection and 50–70% of all individuals with symptomatic cysticercosis have epileptic seizure. Information is generally scarce about the source of these parasites, how they live in the human body, and most importantly how they cause illness. The paucity of diagnostic methods and the lack of consistent intervention studies as part of integrated helminth control strategies means this infection is still neglected. The disease is most commonly recorded in members of agricultural societies with poor sanitary conditions and economies based on breeding pigs with low hygiene standards. However, the disease has been increasingly reported in the developed world because of immigration from endemic countries. In the USA, almost 2000 people are diagnosed with neurocysticercosis every year according to the UN report. Although the clinical features of neurocysticercosis are well understood and the availability of antiparasitic drugs is good, the treatment remains controversial. Much of the controversy arose from the seizure occurrence and other neurological disorders caused by inflammation associated with the antiparasitic treatment. For years, the main debate among experts has been on the usefulness and potential dangers of cysticidal treatment, steroids, and antiepileptic drugs. In the past 10 years, data from different controlled trials have suggested that treatment with praziquantel or albendazole with corticosteroids increases radiological clearance in people with few and uninflamed cysts. In these trials, the primary outcome was partial or www.thelancet.com/infection Vol 14 August 2014
complete cyst resolution. Other controlled studies have shown that with high load of cysts radiological clearance might be lower. In these studies, the presence of inflamed cysts reduced the benefits of anticysticercal treatment with albendazole. Findings of other studies have shown that compared with albendazole alone, combined treatment with praziquantel and albendazole are better and quicker. In this issue of The Lancet Infectious Diseases, Hector Garcia and colleagues report the results of a three-group randomised trial in which the standard albendazole dose (maximum 800 mg per day), an increased albendazole dose (maximum 1200 mg per day), and a combination of albendazole and praziquantel (in standard doses) were tested. However, as pointed out in the linked Comment by Gagandeep Singh and Arthur Clinton White, a complete resolution of cysts was not associated with complete resolution of seizures. According to a new evidence-based guideline from the American Academy of Neurology published April 9, 2013, the combination of albendazole plus a corticosteroid should be considered for adults and children with parenchymal neurocysticercosis. In view of the complexity of the disease and the different forms in which it can manifest, it will be important for guidelines to distinguish between the different forms of neurocysticercosis. Although the trial by Garcia and colleagues represents a big advance in the treatment of parenchymal cysticercosis, new trials with seizure outcome will be welcome. Clearance of seizures should be the ultimate goal of any type of intervention in the treatment of neurocysticercosis. Decreased numbers of seizures would mean a better quality of life for patients. The efficacy of antiepileptic drugs in treating or decreasing the occurrence of subsequent seizures secondary to parenchymal neurocysticercosis is also unclear. Future studies will also be need to establish the appropriate use of adjuvant corticosteroids. Public health efforts together with global collaborations will be of fundamental importance to deliver better diagnostic methods and therapeutic interventions to eradicate this still neglected neuroinfection. ■ The Lancet Infectious Diseases
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Treatment of neurocysticercosis
See Comment page 658 See Articles page 687 For more on the UN report see http://www.fao.org/3/a-i3649e. pdf For more on neurocysticercosis see PLoS Negl Trop Dis 2012; published online May 29. DOI:10.1371/journal. pntd.0001500 For more on trials promoting albendazole see Arch Intern Med 1995; 155: 1982–88 For trials on combination of praziquantel and albendazole see Trop Med Parasitol 1993; 44: 192–94 For more on the guidelines see Neurology 2013; published online April 9. DOI:10.1212/ WNL.0b013e31828c2f3e
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