Okay...that is tremendously gross, but I have a couple of problems with this whole picture, reality-wise.
First off, don't they always completely shave someone's head when they are going to remove the top of their skull? This guy has hair going right up the incision line.
Second...the forehead of the infested skull is tremendously distended...wouldn't this have clued someone in that there was a problem?
Finally, why would you see anything crawling under the scalp when the infestation is in the brain? The skull doesn't ripple when things crawl under it.
This may be a real brain, but I think it is a real dead brain Photoshopped onto a picture of a Japanese patient.
And Snopes says it is fake...
http://www.snopes.com/photos/maggots.asp