Neurocysticercosis Update

Elaine Rosenfeld, M.D.


Pediatr Infect Dis J. 2003;22(2) 

In This Article


Cysticercosis, most common parasitic disease of the central nervous system (CNS), affecting thousands of people in developing countries, is transmitted by fecal-oral contact by ingesting eggs of the porcine tapeworm, Taenia solium, by heteroinfection from a contact harboring the adult tapeworm or by autoinfection. The prevalence of neurocysticercosis (NC) in some developing countries exceeds 10%, where it accounts for up to 50% of cases of late onset epilepsy. In the past decade NC has been diagnosed with increasing frequency in industrialized nations. Several cases of NC have been reported in the US in both large metropolitan centers and less urban areas, in persons who lacked apparent risk factors for the disease. Factors contributing to the increased diagnosis of NC include increased immigration from endemic areas, travel to and from such regions throughout the world and improved diagnostics.[1,2]

NC can be either active or inactive. Active NC is characterized by viable or degenerating cysticerci on imaging studies. Inactive lesions represent scars at sites of prior active infection, characterized by calcified foci. Clinical manifestations of NC are varied and nonspecific, related to the number, age and location of the cysts and the accompanying host immune response. The most common manifestations of NC are seizures, headaches, behavioral disturbances and signs and symptoms of increased intracranial pressure. Children most commonly have a solitary parenchymal lesion and present with an afebrile focal or generalized seizure. Cysticercotic encephalitis is a severe form of NC seen occasionally in children with large numbers of inflamed cysticerci. These patients show signs of acute encephalitis and diffuse brain edema. Signs of increased intracranial pressure are seen in patients with obstructive hydrocephalus caused by active or inactive ventricular cysts. Degeneration of cysts may be associated with a strong host inflammatory response in the brain tissue, which can produce signs and symptoms of encephalitis.[3,4]