Neurocysticercosis(NCC)

Neurocysticercosis(NCC) is a parasitic infection in which pork tapeworm larvae form cysts in the brain or nervous system. It is one of the most common causes of acquired seizures worldwide.

Common symptoms can include:

• Seizures
• Headaches
• Nausea or vomiting
• Confusion or memory problems
• Balance or vision issues

It is diagnosed with brain imaging (CT or MRI) and sometimes blood tests.

The life cycle:

1. Pigs eat food/water contaminated with tapeworm eggs from human feces
2. Eggs hatch in pig → larvae form cysts in pig muscle = "pork measles"
3. Humans eat undercooked pork with cysts → adult tapeworm grows in human intestine = taeniasis
4. The adult worm sheds eggs in human stool
5. If a human ingests those eggs → eggs hatch → larvae travel through bloodstream → lodge in brain, eyes, muscle, skin = cysticercosis

Key point: You get intestinal tapeworm from eating undercooked pork. You get neurocysticercosis from ingesting eggs from someone else’s feces. You can actually give yourself NCC if you have a tapeworm and have poor hand hygiene.

Once cysts are in the brain they cause problems by:

• Mass effect - cysts take up space → increased ICP
• Inflammation - when cysts start dying, huge inflammatory response
• Seizures - most common symptom, ∼70% of cases
• Hydrocephalus - if cysts block CSF flow
• Stroke, meningitis, visual loss if cysts are in critical areas

1. Personal hygiene - breaks the fecal-oral cycle

• Wash hands thoroughly with soap after using toilet, before eating
• Wash hands after handling raw pork
• Don't defecate in open fields

2. Food safety

• Cook pork to ≥145°F internal temp, let rest 3 min. Freezing at -4°F for 4+ days also kills cysts
• Wash fruits/veggies thoroughly, especially in endemic areas. Peel when possible
• Drink safe water - bottled or boiled in endemic regions

3. Sanitation

• Proper sewage disposal so pigs can't access human feces
• Don't use "night soil" as fertilizer for crops
• Meat inspection programs to detect infected pork

4. Treat human tapeworm carriers

• If someone has taeniasis, treat with praziquantel or niclosamide to stop egg shedding
• Screen household contacts of NCC patients - they might be asymptomatic carriers

If someone has NCC, extra precautions:

• Seizure precautions: no driving, swimming alone, heights until cleared
• Anti-epileptic drugs often needed long-term
• Steroids + antiparasitics during treatment to control inflammation when cysts die. Never give antiparasitics alone in heavy brain cyst load - can cause severe brain swelling

NCC is common in Latin America, sub-Saharan Africa, and South  Asia. But with travel and immigration, it is seen in the USA too.

Treatment may involve:

• Anti-parasitic medications
• Steroids to reduce inflammation
• Anti-seizure medicines
• Occasionally surgery

https://www.youtube.com/watch?v=Y7pvUtCNeWE

https://www.cdc.gov/parasites/resources/pdf/npi_cysticercosis.pdf.

Author

Paddy Kalish OD, JD and B.Arch Author and Blogger