RFK Jr. Had a Dead Brain Worm. How Does a Parasite Get Into the Brain?

Brain worms have taken social media by storm after The New York Times reported on Robert F. Kennedy Jr.’s 2012 deposition, where the current presidential candidate said a parasitic worm made its way to his brain “and ate a portion of it and then died.”

Kennedy claimed that the parasite had caused brain damage and memory loss, from which he has since recovered.

Based on the symptoms described by Kennedy, doctors interviewed by The New York Times said the parasite was likely a pork tapeworm, Taenia solium. If someone ingests the eggs—which can spread via the feces of a person with a tapeworm—the eggs can travel to other organs, such as the brain, and form cysts, a condition called neurocysticercosis.

It can take months to years after infection for the symptoms to occur, usually when the cysts start dying. Seizures and headaches are the most common symptoms of neurocysticercosis. Confusion, difficulty with balance, and lack of attention to people and surroundings may also happen. This could result in death.

People cannot get this condition from eating undercooked pork unless the pork contains larval cysts. The eggs are typically spread through food, water, or contaminated surfaces. Those who live in close proximity to an infected individual are at a higher risk of infection.

What Happens When a Tapeworm Infects the Brain?

Claudia Perez, MD, an associate professor and neurology clerkship director at Texas Christian University, said that the tapeworm itself doesn’t cause damage, but rather the brain’s reaction to a cyst is what leads to symptoms.

“What ends up happening is the silent cysts that live in the brain are actually detected by your own body,” Perez told Verywell. “Once your body detects that something’s there, it mounts an immune response. And so what ends up causing the symptoms is the immune system trying to attack that cyst.”

Following this immune response, the cyst can rupture, leading to swelling, inflammation, and excess fluid in the brain. Perez explained the worm doesn’t “eat” brain tissue, but it can become calcified, resembling a scar on the brain.

Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center, said the evidence of neurocysticercosis often appears during imaging for unrelated health issues.

“They’re very commonly seen when we get head CTs on people for other issues, for example, a headache, or a trauma, or a little confusion,” Segil told Verywell. “You see these abnormalities in the brain that look like teeth because they’re calcified or they look like little chips of bone in the brain.”

How Can You Avoid Getting a Brain Worm?

Segil said people who contract neurocysticercosis multiple times are at a higher risk of experiencing symptoms like seizures. Treatment options may include surgery to remove the cysts, as well as anti-parasitic medications and anti-inflammatories to eliminate the parasite and alleviate inflammation.

Cysticercosis is primarily seen in rural areas of developing countries, where pigs roam freely and consume human feces, according to the CDC. Sometimes people can get this condition even if they’ve never traveled outside of the U.S.

To best protect yourself from a tapeworm infection, you should always wash your hands with soap after using the toilet, changing diapers, and before handling food.

“To prevent neurocysticercosis infections, one should always go to restaurants where there is good hygiene,” Segil said. “This is a reason people sometimes shy away from street vendors for food, because street vendors for food with pork products make you at high risk for this.”