And now it's time for the CGI medical explanation segment of the program. The Magic School Bus Cam swirls around, following a nasty-looking spiky ball thing that is the measles virus. House voice-overs that before his vaccination, Dan got the measles. It made him sick, but he survived. We go inside the virus to a strand of DNA (which I don't think is accurate, since viruses only have RNA, although this graphic may very well be RNA and I just don't know how to identify a double helix), which snaps as House explains that, in a one-in-a-million freak occurrence, the virus mutates. Then it travels to his brain and hides for sixteen years before it resurfaces as subacute sclerosing panencephalitis. It's rare as hell, with only twenty cases in the US in the last twenty years, but that it can be treated as long as it's still in stage one with intraventricular interferon. This conflicts with everything I read about SSPE, which said it's always fatal, and quickly. Some remissions have been reported, but they were only temporary. Dan was better off with the MS and the lumbar punctures. The interferon treatment involves "shoving a spike into his brain," as Chase puts it, which they can't do unless they have a confirmed diagnosis. But that can't get that because all the drugs they've given him for their diagnosis mistakes will create false readings on future tests. "So the wrong treatment kills any hope of the right diagnosis. WHY do people LIE to me?" House says, like, WHY do you treat people for things without being certain that it's what they actually have? Foreman says that there is another way.
Cut to Dan strapped into a chair with a long, sharp needle slowly heading toward his face. It's like Dan's night terrors, except even worse and real. Foreman assures Dan that this won't hurt (although I don't see how anything could ever hurt Dan again after those lumbar punctures). The needle goes right on into the kid's pupil, through his eye, and into his retina, where it takes gets its biopsy sample.
The results are in, and Dan's got crazy measles! Foreman tells the parents and discusses the treatment options, which the parents understandably are having trouble understanding. So Foreman gives up and says it's impossible to describe all this medical stuff, so he'll just settle for saying that the intraventricular interferon treatment is "dangerous. It could kill him. You should do it."
Brain surgery time! Dan gets to be awake and aware as a drill bores through his skull.