Joel Grey, the actor who plays Ezra Powell, played the Wizard of Oz in the Broadway show "Wicked." As Dr. House examines Powell behind a blanket, House says, "Pay no attention to the man behind the curtain," a quote from The Wizard of Oz (1939).
Leighton Meester (Ali) also has an infatuation with Hugh Laurie's character in the movie The Oranges (2011).
The wall clock in the MRI room is labeled 'Stoia Tucker,' which is also the pharmaceutical company in TB or Not TB (2005) (Most likely from Chris Stoia, first assistant director on the show.)
House references Shakespeare's "The Merchant of Venice" when he asks Cameron to bring him "a pound of flesh."
House says, "Don't go towards the light", referring to the movie Poltergeist (1982) and its sequels, where the main character Carol Anne is told not to "go into the light". A "white light" association occurs in many near-death experiences.