RFK Jr. says dead worm may have been in his brain, here's how they get there

• Kennedy said some doctors concluded he had a brain tumor, but one at New York-Presbyterian Hospital proposed Kennedy may have had a dead parasite in his head.
• In the deposition, Kennedy said the doctor believed the spot "was caused by a worm that got into my brain and ate a portion of it and then died."

How it works: A parasitic infection of the nervous system is called neuroparasitosis.

• The most common type of neuroparasitosis, neurocysticercosis, is caused by larvae of the pork tapeworm, which is what infectious disease experts and neurosurgeons interviewed by the Times said Kennedy might have had in his brain.
• People generally develop neurocysticercosis by swallowing microscopic pork tapeworm eggs passed in the feces of a person who has an intestinal tapeworm, according to the Centers for Disease Control and Prevention.
• A common method for spreading the tapeworm is when a person who has one doesn't wash their hands properly and prepares food that is eaten by others.

Zoom in: Once the microscopic eggs are ingested, they hatch, invade the intestinal wall, enter the bloodstream and can migrate and form cysts in multiple tissues, including brain tissue. On brain scans, the cysts can appear as dark spots.

• They can survive unnoticed in tissues for several years, as they suppress the host's immune response.

Yes, but: The parasitic cysts, or cysticerci, do not "eat" tissues as Kennedy said. They instead siphon nutrients from their host.

• When they form, they can cause tissue damage. Symptoms also generally appear when the cysts start dying, triggering a large inflammatory response from the body.
• If they have developed in the brain, the cysts can cause seizures and headaches, confusion, lack of attention to people and surroundings, difficulty with balance and excess fluid around the brain.
• They can also be fatal.

Between the lines: Kennedy's campaign did not provide the Times with the candidate's medical records, meaning the brain worm diagnosis could not be confirmed.

• Kennedy made the comment while arguing in divorce proceedings that his earning power was diminished by his cognitive issues.

What they're saying: Kennedy's campaign said in a statement he has traveled extensively in Africa, South America and Asia through his environmental work and contracted a parasite on one of those continents.

• "The issue was resolved more than 10 years ago, and he is in robust physical and mental health," the campaign said.

Go deeper: The battle for the Kennedy name heats up