Why is deep brain stimulation surgery performed in multiple stages?

Deep brain stimulation surgery is a two-stage procedure. The first surgery is done while you're awake, and we want to do it in as painless a fashion as possible. It’s impossible to implant a generator without inducing a lot of pain because we need to pass the generator under the skin and implant it into the chest, so we do it in two stages for two reasons. One is we can have you awake for the actual brain implant, where we need you awake, and then we can do the second stage with you asleep, and you don’t have to experience any of the pain that you might have otherwise experienced for the generator implant.

The other issue is that one of the biggest concerns about these surgeries is bleeding in the brain, and one of the most important tools that we have as neurosurgeons, as neurologists, is to examine our patients as we’re doing the surgery. What we don’t want to do immediately after we do a surgery like this is put you to sleep so that we can’t examine you anymore and not know if anything unexpected is happening. It’s really for patients’ safety that we stage these procedures.