DBS and Parkinson's

DBS was FDA approved for Parkinson’s disease tremor back in 1997 (along with essential tremor), followed by approval for advanced Parkinson’s symptoms in 2002, and most recently for earlier stages of Parkinson’s (patients who have at least 4 years of disease and poor symptom management) in 2015. 

It is one of the most important therapeutic advances since discovery of levodopa, and while it is not a cure for Parkinson’s disease, it can substantially improve one’s quality of life. 

When considering DBS one should understand the facts, avoid misconceptions, and have realistic expectations. 

What symptoms does DBS treat?
What about gait and balance?
When should someone consider DBS?
How is candidacy determined?
What is the process?
What are the outcomes?