Learning Radiology xray montage


General Considerations

  • Most common parasitic infestation of central nervous system worldwide
  • Caused by the pork tapeworm, Taenia solium
  • Most important manifestation of disease is in central nervous system-neurocysticercosis (NCC)
  • Endemic areas include Mexico and Latin America, sub-Saharan Africa, India and east Asia
  • Incidence in USA is increasing from immigration and travel
  • Life cycle
    • Humans are definitive host of intestinal tapeworm
    • Pigs are intermediate host
    • Human cysticercosis develops when eggs or larva are ingested through fecal-oral transmission from a tapeworm host or in undercooked pork
    • Cysticerci (larval cysts) develop within organs
      • Skin, skeletal muscle, CNS, heart, eye


Life cycle.gif


Life Cycle of Taenia Solium (Pork Tapeworm) (From CDC)


Clinical Findings

  • Dependent on pericystic inflammation
  • If no inflammation, usually asymptomatic
  • Seizures
  • Chronic headache
  • Nausea and vomiting
  • Mental status change
  • Vision changes

Imaging Findings

  • Usually parenchymal in brain
    • May be ventricular or subarachnoid
  • Involuted, degenerated cysts calcify and appear oblong or cigar-shaped
  • CT is the imaging study of choice for NCC
    • Calcifications
      • Calcified cysts are usually not associated with surrounding inflammation
    • Non-enhancing cystic lesions with/without surrounding edema
    • Mass effect
    • Hydrocephalus
  • MRI may demonstrate cysts with then ventricular system
    • Lateral, 3rd and 4th ventricles

Differential Diagnosis

  • Coccidiomycosis
  • Toxoplasmosis
  • Tumor
  • Trichinosis
  • TB


  • Anti-helminthic medications


  • Encephalopathy
  • Obstructive hydrocephalus
  • Sequelae of treatment from steroids or anti-convulsants
  • Calcified cysts may be epileptogenic


  • Excellent in most cases 

Cysticercosis. White arrows point to calcified cysticerci scattered throughout the
brain parenchyma with no surrounding inflammation. The right shoulder demonstrates
multiple cigar-shaped, muscular calcifications, again representing cysticerci.

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Cysticercosis: Differential Diagnoses & Workup. eMedicine. Ryan Tenzer, R and Blumstein, H.