A UK resident who suffered headaches and seizures for four years was ultimately handed an unusual explanation for his woes: There was a worm in his brain, reports the Guardian. Specifically, doctors removed a 1-centimeter-long tapeworm called Spirometra erinaceieuropaei. Based on scans taken over several years, the worm traveled about 2 inches from the right side of his brain to the left, though doctors didn't realize it was a worm until they conducted a biopsy. The 50-year-old patient is mostly fine, though he's still suffering some issues due to having served as host for the parasite. This particular tapeworm most generally affects amphibians and crustaceans, and is exceedingly rare in humans: In roughly six decades, only 300 cases have been recorded.
The one upside is that scientists were able to sequence its genome, they report via Eureka Alert. That should enable them to more easily identify and treat for it in the future. “This genome will act as a reference, so that when new treatments are developed for the more common tapeworms, scientists can cross-check whether they are also likely to be effective against this very rare infection," says a Cambridge geneticist. It's not clear how the man got infected, but the best guess is that he picked it up on a visit to China, perhaps from infected meat or water. The mouthless tapeworm is thought to have absorbed nutrients from the brain directly into its body. (In India, doctors once found a worm inside a patient's eye.)