Neurocysticercosis. An introduction with special emphasis on new developments in pharmacotherapy.

Neurocysticercosis is the most important parasitic infection of the nervous system in countries of the third world. The disease is caused by the cystic larval stage of Taenia solium, the pork tape worm. The clinical picture of neurocysticercosis is due to the parasite itself and/or an inflammatory reaction around degenerating cysts in the central nervous system. It may cause epilepsy, chronic meningitis and hydrocephalus. The diagnosis is greatly facilitated by the use of computer tomography, magnetic resonance imaging and serological tests. Praziquantel and albendazole now offer a reasonable treatment for neurocysticercosis. However, the effect of praziquantel is largely dependent on its bioavailability, which is decreased by the use of antiepileptics and, possibly, dexamethasone. Albendazole is associated with side effects on bone marrow and liver, and it has teratogenic and mutagenic properties. Both drugs act poorly on intraventricular cysts. Coadministration of cimetidine with praziquantel leads to a significant two-and-a-half times' increase of the latter drug's bioavailability. This resulted in a good clinical response to treatment for 12 patients with various forms of neurocysticercosis. Although neurocysticercosis is no longer endemic in many Western European countries, its incidence is likely to increase due to increased travel to, and immigration from, endemic countries.