"Surgeons thought Rosemary Alvarez had a brain tumour, but on operating they discovered the worm."

If you want to see what it looks like -- removing a worm from a brain -- there is live-action video at the link. If it makes you feel like not eating, keep in mind that she got that worm in something she ate. Oh, don't worry! Cook your meat thoroughly -- make sure all the worms are dead.