Extraparenchymal neurocysticercosis: report of five cases and review of management.

Neurocysticercosis due to parenchymal cysts carries a good prognosis regardless of therapy. Extraparenchymal neurocysticercosis (including ventricular, spinal, and subarachnoid types) carries a poorer prognosis. Most extraparenchymal cases present with hydrocephalus. Medical treatment alone in doses and schedules developed for parenchymal disease is frequently unsuccessful. For ventricular disease, most cases can be managed with shunting procedures either alone or together with the administration of antiparasitic agents (e.g., praziquantel or albendazole), without extirpation of the cysts. Subarachnoid disease was formerly associated with a case fatality rate of about 50%. However, with the combination of shunting procedures for hydrocephalus, antiparasitic agents, and, in some cases, surgical extirpation of the cysts, the prognosis is much improved. Spinal cysticercosis can be either leptomeningeal (which responds like subarachnoid disease) or intramedullary. For all forms of neurocysticercosis, the role of antiparasitic agents needs to be better defined.