In pigs, tapeworm larvae travel to the brain and await transmission to another animal (a human, for instance) when the pigs are eaten, he said. The parasites do the same thing in humans, but there's nowhere to go from the human brain. Ultimately, the larvae die, and that's when the trouble begins.
As the larvae die, they lose the ability to hide from the body's immune system. The immune system responds by causing inflammation, which leads to epileptic seizures and brain swelling, Hotez said.
The guidelines for children and adults recommend using the medication albendazole to kill the cysts if they're alive and treating brain swelling with corticosteroid drugs that dampen the immune system. The study found that albendazole (Albenza), used with or without the corticosteroids, reduced seizure frequency and the number of brain lesions seen in imaging scans. Not enough data was available to evaluate another drug, praziquantel, the researchers said.
Only limited evidence exists to support specific treatment approaches, however, and the treatments may produce side effects, such as abdominal complaints, according to the guidelines. It's also unclear whether anti-epileptic medications may help prevent the seizures caused by the inflammation.
For now, the key is physician awareness, said Dr. Karen Roos, a professor of neurology at the Indiana University School of Medicine and lead author of the guidelines. "Physicians from areas of the world where this infection is endemic are very knowledgeable about this infection," she said. "They know more than U.S. physicians."
Infection with the tapeworm is preventable through proper sanitation, good hygiene and thorough cooking of meat.
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