Accident and ParalysisEdit
Mickey was drunk and caused an accident which killed two teenage girls, named Lindsay and Cheryl, and left him paralyzed from the neck down.
Feeling guilty about having killed two teenage girls and then having to have people take care of him around the clock, Mickey signed up for Callie and Derek's brain mapping trial, seeing it as a way to help other people. The sensors were successfully implanted and he was able to control the computer with his mind, using it to control a digital hand and play a computer game.
Tumor and DeathEdit
Mickey's progress in the trial was halted when it was discovered that he had low activity in his temporal lobe due to a brain tumor. It went into the brain stem, meaning that neither embolization glue nor removal was an option. He asked Derek to allow him to continue the trial, but Derek declined, saying that the tumor could affect the results and bias the trial and that it couldn't be removed. Mickey then declined consent for Derek to remove the sensors unless he also agreed to remove the tumor. Since Callie had a previous relationship with Mickey as he was originally her patient, Derek asked her to talk to Mickey and convince him to let Derek remove the sensors.
When Callie went to Mickey, he told her the story of how he became paralyzed. He told her about how he wanted to do the trial so that he could help other people and feel like less of a burden. She went back and convinced Derek to try to remove the tumor.
Derek operated, but Mickey was pronounced brain dead in the OR. However, Derek and Callie later harvested his brain to help them in their research.