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Brain Tapeworms

Brain Tapeworms

What are brain tapeworms?

Tapeworms are parasites generally associated with the intestines, but in some case, these gastrointestinal dwelling mites can migrate to brain, where they unleash a barrage of irreversible damage on the brain.

Otherwise known as Neurocysticercosis (NCC), brain tapeworms can eat away at brain matter leaving the muscle looking like a rotting apple eaten by worms.

Unfortunately, they are much more common than you’d think. While its difficult to pin point exactly how many people suffer from this condition, Theodore Nash, who is the chief of the Gastrointestinal Parasites Section at National Institutes of Health in Bethesda estimates that up to 1000-2000 Americans may suffer from brain tapeworms. The number of case worldwide is much more difficult to estimate since most of the infections occur in countries that lack a good medical infrastructure. However Nash says that there are “Minimally there are 5 million cases of epilepsy from neurocysticercosis.”

Nash puts heavy emphasis on the word ‘minimally’, noting that the closer they look into the disease, the worse it becomes. He and other neurocysticercosis experts have been travelling through South American with CT scanners to get more accurate results. In one study conducted in Peru, researchers found that 37 percent of those tested had shown signs of infection at some stage in their life.

brain tapeworms 550x309 Brain Tapeworms

Brain Tapeworms – Neurocysticercosis

Using data from similar studies, Nash and his colleagues recently published a paper that estimates 11 to 28 million people suffer from the disease in Latin American alone. With tapeworms being common in Africa and some parts of Asia, the global number of people with neurocysticercosis could be in the hundreds of millions.

Tapeworms, or Taeniasis, are caused by a transmission of larvae between pigs and humans. Tapeworms living in humans produce around 50,00 eggs, which are shed in the person’s feces. Pigs can accidentally swallow the infected feces when rummaging for food on the ground. Inside the pig the larvae hatch and burrow their way into the animals’ bloodstream. From here the parasites can end up in the small blood vessels of the muscle where they form cysts and wait to be consumed again by humans.

Neurocysticercosis happens when this cycle gets jumbled and the eggs inside the infected feces make their way back to human, instead of the pig. If a human consumes the eggs, the larvae react as they would inside a pig, by borrowing into the bloodstream. When this happens the larvae can reach the brain, where it forms a cyst that protects it from the body’s immune system for years.

As the cyst grows it can push on the brain causing pain or disrupting its function, it may block the flow cerebrospinal fluid, which can lead to water on the brain, brain herniation, seizers, and convulsions.

Eventually, a tapeworm cyst that cannot move on to its adult stage will die. When this happens our immune systems crank up in a last ditch effort to get rid of the foreign body. Immune cells quickly destroy what’s left of the cyst, but damage often occurs. The attack can cause inflammation and damage to surrounding tissues, and for reasons still unknown, the cyst can keep triggering these responses for years after the parasite death.

Treating neurocysticercosis hasn’t been as easy as dealing with intestinal tapeworms. In the 1980’s the first drug to effectively kill tapeworm larvae, praziquantel, became available. This worked wonders for intestinal infections, but caused an immune reaction that would lead to massive swelling if the larvae were lodge in the brain.

Over the years, Nash and his colleagues worked to find a combination of drugs that would rid the body of tapeworms and keep brain swelling down to a minimum. So far the team has had some success using the method, but it’s far from perfect. Sometimes the immune system still overreacts and immune-suppressing drugs have side effects of their own.

Nash and his team are now looking at ways to rid pigs of cyst before they can infect humans. Unfortunately, there isn’t much work being done on this particular condition, which means few resources are available. Nash said:

“I see this as a disease that can be treated and prevented. All of this seems to be very feasible, but nobody wants to do anything about it.”

Hopefully, as more research is conducted into how to effectively treat, and possibly even eradicate brain tapeworm, Nash and others like him may come up with a plausible answer.


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  1. Carl Zimmer: The Brain Hidden Epidemic: 
Tapeworms Living Inside People’s Brains. Discover Mag, 05/15/2012.
  2. Lesie Horn: Brain Tapeworms Are Real, And They’re Disgusting. Gizmodo, 05/16/2012.

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