Doctors interviewed by ABC News clarified that these types of parasites don’t actually eat brain tissue. Rather, they absorb nutrients passively before dying.
According to doctors interviewed by ABC News, an infection like this could lead to seizures, which could potentially cause short-lived memory problems as Kennedy described, but most patients would mount a full recovery.
https://abcnews.go.com/Politics/rfk-jr-claims-doctor-parasite-ate-part-brain/story?id=110027317