While packing for the trip, he said, he received a call from a doctor at NewYork-Presbyterian Hospital who had a different opinion: Kennedy, he believed, had a dead parasite in his head.

The doctor believed that the abnormality seen on his scans “was caused by a worm that got into my brain and ate a portion of it and then died,” Kennedy said in the deposition. ...

About the same time he learned of the parasite, he said, he was also diagnosed with mercury poisoning, most likely from ingesting too much fish containing the dangerous heavy metal, which can cause serious neurological issues.

“I have cognitive problems, clearly,” he said in the 2012 deposition. “I have short-term memory loss, and I have longer-term memory loss that affects me.”