André Bormanis consulted with his friend John E. Glassco, a pathologist at St. Josephs Hospital in Burbank, to make the medical dialogue as authentic as possible.
Although the producers were happy with both the A-story and the B-story as individual stories, they were not happy with their combination in this episode.
The original pitch for this episode, by Christian Ford and Roger Soffer, was based on the 1818 Mary Shelley novel Frankenstein, with Bashir in the role of Dr. Victor Frankenstein. The story concerned a Federation ambassador involved in peace negotiations with the Romulans whose shuttle is damaged and who dies in the sickbay on Deep Space 9. However, the treaty negotiations are at a pivotal moment, so Bashir is able to figure out a way to "re-animate" the ambassador's brain, essentially bringing him back to life. However, over the course of the episode, he begins to go mad, and in the last scene, Bashir is forced to allow him to die once again. The reason this idea was scrapped was because the producers felt that the audience wouldn't have much empathy with a character who they'd only just been introduced to.
While shooting her scenes Louise Fletcher (Kai Winn) was extremely ill with the flu and had to lie down between takes.
Jim Martin designed two major props for this episode: a "brain scanner" and a "brain operator." The scanner was a small light-weight device which would be placed over the head, the operator was a large device which enclosed the head, apart from a small opening at the back. However, when Martin saw some of the dailies for the episode, he was amazed to see the scanner being used as the operator and vice versa. Director Reza Badiyi couldn't figure out which was which, so he took a guess. Martin thought this mix up was hilarious.