Disease Information for Cysticercosis

Infection with CYSTICERCUS, a larval form of the various tapeworms of the genus Taenia (usually T solium in man); In humans they penetrate the intestinal wall and invade subcutaneous tissue, brain, eye, muscle, heart, liver, lung, and peritoneum; Brain involvement results in NEUROCYSTICERCOSIS; (From Dorland, 28th ed)------------------History of exposure to Taenia solium in an endemic region; concomitant or past intestinal tapeworm infection;

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 (see above); Worldwide, an estimated 20 million persons are infected and 50,000 deaths occur yearly; Antibody prevalence rates to 10% are recognized in some endemic areas; The infection is one the most important causes of seizures in the developing world; 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; 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 , subcutaneous tissues and striated muscle, vitreous humor of the eye, other tissues;

When symptomatic, the incubation period is highly variable (usually from 1 to 5 years); lesions on neuroimaging studies, (2) positive immunologic tests with serum fluid, cysticercosis outside the central nervous system, clinical history, Plain radiographs of muscle (especially of thigh and calf) may detect oval or linear calcified lesions (4–10 x 2–5 mm); The lesions are usually multiple, sometimes in the hundreds, and the long axes of the cysts are nearly always in the plane of the surrounding muscle fibers; (Current Medical DX RX 2005)

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