He also established the Peterson for Parkinson's Foundation, which raises money to benefit Parkinson's Disease research, education and support groups.
"One of the reasons that he had to ultimately leave the (bench) is the fact that he couldn't go on the ice because he'd get locked up," Trotz told NHL.com. "He said I'm fearful for the players because I can't get out of the way and I may hurt someone, but I'm more fearful for myself because I can't get out of the way and I can't do my job the way I was hoping I could."
In a video taken by ABC-2 in Nashville, Peterson is seen shuffling into the hospital, barely able to walk down the hallway prior to the final stage of the DBS. After Dr. Tom Davis activates the electrodes, Peterson is able to walk like a normal person.
"It's a lifesaver," Peterson said in the video. "It's a lifesaver for me and it's pretty cool just to be able to do the things you couldn't do before."
It's also been gratifying for Trotz to watch his friend get his life back.
"It's amazing," said Trotz. "Brent obviously has dealt with Parkinson's for a number of years. Really in the last year you could really notice him getting locked up and shuffling -- really shuffling like he was 90 years old. Which is really, really sad. If you've spent any time with Petey (Peterson) you'd understand how sad that is because he's such a great human."
The final stage of Peterson's DBS procedure was performed in December, and while doctors warn it's not effective on all Parkinson's patients, Peterson has responded well.
"It's come together where he's gone back in time 20 years," said Trotz. "He's walking around. He's always a guy with a lot of energy and he's literally wired up. We say that -- he's got the brain stimulation and he's really wired up. He's moving around like he's 20 years old. It's fabulous. It's very inspiring for our team. It's very inspiring for our team, for anyone who has a disability or a disease such as Parkinson's. What science and medicine have come up with is astounding."
As far as Peterson has come, Trotz doesn't believe he'll ever have Peterson back on the bench with him. That's OK, though; Trotz says he's just happy his friend can get back to living a normal life.
"What the doctors have said is that (being on the bench) may probably be a little bit of a long shot," said Trotz. "But he can have his life back. He can still work in hockey."
Contact Adam Kimelman at email@example.com. Follow him on Twitter: @NHLAdamK