Independent presidential candidate Robert F. Kennedy Jr. has disclosed a series of health issues he has faced in recent years, one of which involves a worm-like parasite that entered his brain but ultimately died.

Kennedy, 70, recounted his severe memory loss and mental fog in 2010, which prompted him to consult renowned neurologists familiar with his late uncle Sen. Ted Kennedy’s medical history. After a brain scan, a New York doctor suggested that Kennedy’s health problems could potentially be attributed to a worm that had entered his brain and consumed a portion of it before it died. In a deposition related to his divorce from his second wife, Mary Richardson Kennedy, in 2012, Kennedy expressed that these cognitive issues had negatively impacted his earning potential.

In that same period, Kennedy also experienced mercury poisoning, a condition associated with neurological symptoms such as peripheral vision loss, muscle weakness, movement difficulties, hearing and speech impairment,...