Neurocysticercosis: a review

Abstract

Neuroysticercosis is the most common helminthic infection of the nervous system, and a leading cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of Taenia solium by ingesting its eggs from contaminated food or, most often, directly from a taenia carrier by the fecal-to-oral route. Cysticerci may be located in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing pathological changes that are responsible for the pleomorphism of neurocysticercosis. Seizures are the most common clinical manifestation, but many patients present with focal deficits, intracranial hypertension, or cognitive decline. Accurate diagnosis of neurocysticercosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunological tests. The introduction of cysticidal drugs have changed the prognosis of most patients with neurocysticercosis. These drugs have shown to reduce the burden of infection in the brain and to improve the clinical course of the disease in most patients. Further efforts should be directed to eradicate the disease through the implementation of control programs against all the interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Figure 1

World map showing countries where cysticercosis is endemic.

Figure 2

Life cycle of Taenia solium showing the normal cycle of transmission, when humans act as definitive hosts and pigs as intermediate hosts, and the aberrant cycle of transmission, when humans become intermediate hosts, developing cysticercosis.

Figure 3

Imaging findings in patients with parenchymal brain cysticercosis, including: viable cysts showing the scolex (a), colloidal cyst appearing as a ring-enhancing lesion (b), and calcifications (c).