Narrator: This is Science Today. Many years ago, if a person was diagnosed with Parkinson’s disease, the prognosis wasn’t very promising. Basically, patients with this degenerative brain disorder had two years of good function and then faced a life of disability. Since then, medication has helped patients with Parkinson’s have many years of good function.

Starr: When levodopa therapy was introduced in 1968 that made the first five to ten years of life with Parkinson’s bearable with good function.

Narrator: Dr. Phillip Starr of the University of California, San Francisco says after five to ten years, complications develop from medications. For these patients, there’s deep-brain stimulation surgery, or DBS.

Starr: We’ve now extended the period of good function and good quality of life another five to fifteen years beyond what medical therapy can do. So we often look at deep brain stimulation, even though it’s not curative, as a bridge to a future time where truly curative therapies will be available.

Narrator: For Science Today, I’m Larissa Branin.