Disease Information for Cysticercosis, cerebral

Neurocysticercosis; History of exposure to Taenia solium in an endemic region; concomitant or past intestinal tapeworm infection; Seizures, headache, and other findings of a focal space-occupying central nervous system lesion; Subcutaneous or muscular nodules (5–10 mm); calcified lesions on x-rays of soft tissues; Calcified or uncalcified cysts by CT scan or MRI; positive serologic tests;Human cysticercosis is infection by the larval (cysticercus) stage of the tapeworm T solium ; Cysticerci complete their development within 2–4 months after larval entry and live for months to 20 years; Initially, a live larva grows within a thin-walled 10–20 mm cyst (the vesicular cyst) but remains minimally antigenic, causes little or no perilesional inflammation, and does not enhance with contrast media on neuroimaging; Attached to the inner wall of the cyst is an invaginated protoscolex with four suckers and a crown of hooks; When host immune response or chemotherapy causes gradual death of the cyst, marked inflammation and pericyst edema can occur, producing a ring-like or nodular area of enhancement with contrast media (the granulomatous or enhancing cyst); concurrent events include cyst enlargement, mechanical compression, increased intracranial pressure, cerebrospinal fluid changes, and sometimes a vasculitis that results in small cerebral infarcts; The immune response is intense in many patients, but some show a remarkable tolerance; Later, as the cyst degenerates over 2–7 years, it may become undetectable with imaging or be replaced by fibrosis with calcification that is detectable; Locations of cysts in order of frequency are the central nervous system (where cysts at different life cycle stages—live, transitional, dead—may be present at the same time), When symptomatic, the incubation period is highly variable (usually from 1 to 5 years); Manifestations are due to mass effect, inflammatory response, or obstruction of the brain foramina and ventricular systems; Neurologic findings are varied and nonspecific, in large part determined by the number and location of the cysts; Acute invasive stage (cysticercotic encephalitis): This rare event, occurring shortly after invasion, results from extensive acute spread of cysticerci to the brain parenchyma; Fever, headache, myalgia, marked eosinophilia, and coma may occur;

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