Neurocysticercosis

Abstract

Cysticercosis is a parasitic disease caused by the larval stage of the human tapeworm Taenia Solium (62). Humans are hosts of the adult form of Taenia sollium, and parasites colonise the small intestines. Pork is the intermediate host, as Cysticercum cellulosae colonises brain, muscle and other organs. Taenia eggs are released by man and can be ingested by pork, which acquires cysticercosis. Man can ingest eggs as well, replacing pork as the intermediate host. Disease is largely diffused in developing countries (63) but developed countries are now detecting an increasing number of cases, mainly as a consequence of immigration. Cysticercosis can affect heart, lungs, liver, subcutaneous tissue, muscle and the eyes. Central Nervous System (CNS) involvement (neurocysticercosis) is the most serious and frequent one. It is the most common cause of seizures in young adults in endemic areas (63). Clinical manifestation of neurocysticercosis varies largely and depends on the number of parasites, localisation, stage of development and immune reaction of the patient. Young adults (11-35 years) are more frequently affected (64), which causes economical problems. Statistical data on brain cysticercosis are not precise, due to diagnosis difficulties and sub-notification. It is estimated (65) that around 50,000,000 people suffer from cysticercosis in the world (around 50,000 deaths, all of them caused by the brain form of the disease). In Latin America, around 13,825,000 people are affected by cysticercosis and 30% are considered to have the parasite in the brain (4,200,000). Disease causes death in 16,4% - 25,9% of the patients (66, 67). Prevalence was 212/100,000 in Peru (1977) and 1,500/100,000 in Brazil (1975). In Mexico, incidence is 2,459 / 100,000 (500 new cases yearly). Inthe USA, detection of the disease is also increasing (66, 68-70).