Cysticercosis is a parasitic infection caused by the pork tapeworm, Taenia solium.

Epidemiology

• Incidence
  • Endemic in Mexico, Central and South America
  • Etiological agent in 10% of new onset seizures

Organism

• Humans are the only definitive host
• The T. solium life cycle begins and ends in pigs
• Humans are incidental hosts by contact with contaminated water or undercooked pork
• Form depends on site of infection
  • Tapeworm in intestine
  • Larval forms in tissues

Clinical Presentation

• Initial infection often asymptomatic
  • Can have rapid onset depending on number of cysts and body site affected
• Symptoms begin when cyst dies and depend on where the cysts are located
• Dying cyst releases antigenic material, triggering the host inflammatory response
  • Neurocysticercosis (cysts in the brain) is associated with seizures, meningoencephalitis, obstructive hydrocephalus
  • Stroke patients initially present with elevated intracranial pressure (ICP), seizures, headache, nausea or mental status changes
• Ocular cysts
  • Usually vitreous, can be subretinal
  • Blurry or disturbed vision, swelling or retinal detachment

Treatment

• Treatment is usually necessary
  • CNS disease may require treatment for hydrocephalus

Diagnosis

• Diagnosis may be difficult, requires high index of suspicion in nonendemic areas
• Clinician should use consensus criteria (see table below)
• Diagnosis is made by MRI or CT brain scans most often, but serologic screening by ELISA and confirmation by Western Blot show increased sensitivity in the diagnosis of cysticercosis