Case 1

1. What is the differential diagnosis in this patient ? 

• The finding of multiple cystic and calcified lesions on CT scan are strongly suggestive of neurocysticercosis.

•  Multiple intracranial lesions that enhance with contrast are seen in toxoplasmosis, CNS lymphoma, nocardia, bacterial seeding with endocarditis, and metastatic cancer.

• Granulomas caused by tuberculosis and histoplasmosis will calcify, but are rarely multiple . 

• Echinococcal cysts rarely involve the brain. 

2. What is the most likely diagnosis and why?

3. How can the diagnosis be established? 

The diagnosis of neurocysticercosis should be suspected on the basis of the 

• CT findings. CT and MR1 are the most effective means of diagnosis.

• The travel history. The prevalence of Taenia solium (pork tapeworm) infection is high in Mexico.

 The diagnosis is strengthened by serology. 

• Serum and CSF ELISA and  immunoblotting assays are available commercially and through the CDC.

  • Sensitivity of antibody testing is higher (94%) for patients with  multiple cysts than a single cyst (28%). 

  • In the presence of a characteristic scan,  negative serology does not exclude the diagnosis. 

• Demonstration of the larva in a biopsy sample confirms the diagnosis. 

• Infection with the  adult worm is made by detection of eggs on stool examination, but T. solium eggs cannot be distinguished from T. saginata. 

4. Interpret the CSF findings.

5. Describe the life cycle of this parasite.

6. Discuss the epidemiology of this parasitic infection.

7. How does infection with this parasite occur? 

• Cysticercosis represents tissue infection with larval cysts of the cestode Taenia solium, in which the patient serves as an intermediate host  for the parasite. 

• It is acquired with consumption of undercooked pork  

• Individuals who ingest T. solium eggs develop tissue infection with  parasite cysts (cysticercosis), while those who ingest larval cysts acquire 'pork' tape worm, i.e., the adult form of T. solium. 

• Mature  tapeworm infection is strictly intra-luminal. Autoinfection can occur. 

• The larval tape worm (oncosphere) penetrate the intestinal wall and  enters the blood stream, and eventually enters tissues and encysts.

•  Tissue cysticerci may remain viable for 2-5 years, and infect humans  when undercooked pork is ingested. 

8. What other organs may be involved? 

• The brain. eye, muscle and subcutaneous tissue can be involved. 

• Cysticerci in brain tend to grow to a larger size than other tissues.

• Eventually, the cysticerci die and become calcified, usually within 2 years 

9.  How would you treat this infection? 

• Drug therapy is the treatment of choice. High doses of praziquantel (50 mg/kg per day for 15-30 days), or albendazole (10-15 mg/kg per day  for 8 days) results in drug levels sufficient to kill remaining living cysts. 

  • Cyst death is often accompanied by increased local inflammation  at the site of infection, leading to a transient increase in symptoms. 

  • The use of dexamethasone to reduce CNS inflammation is  controversial, as it may lower praziquantel levels. 

• Anti-epileptic medication and shunting for hydrocephalus are also important. 

• Surgical  therapy may be required especially for cysts outside the CNS.

10. What control measures are available to prevent its transmission?