Sally Christopher has volunteered as a research patient in three studies since she was diagnosed with Parkinson’s disease more than a decade ago.

“I really enjoy them because I’m very curious by nature,” said the 79-year-old Oak Park Heights, Minn., resident. “It motivates me to learn more about the disease.”

Christopher will participate in a fourth study this spring. The University of Minnesota announced this month that it’s been chosen as one of five clinical sites for a new study focused on finding biomarkers for the disease.

Biomarkers are indicators that allow physicians to better track and diagnose diseases. For example, measuring blood sugar levels can determine if a person has diabetes, said James Cloyd, director of the University Center for Orphan Drug Research.

Discovering a biomarker for Parkinson’s disease could help researchers better predict and diagnose the disease and find treatments, said Paul Tuite, the study’s principle investigator at the University Medical Center, Fairview.

“In the past 20 years, there haven’t been great breakthroughs in Parkinson’s research,” Tuite said, “partially because we don’t have any tests — like blood and spinal fluid — that tell us if a treatment is having an impact on the disease.”

Researchers will take samples from 120 subjects with moderate to severe Parkinson’s, as well as 120 subjects who don’t have the disease, said Reena Kartha, a University College of Pharmacy research associate involved in the study.

Kartha said creating a sample bank of patients and their histories could be a useful resource for Parkinson’s researchers.

Parkinson’s disease is currently diagnosed exclusively by clinical observation, so it’s mostly dependent on movement-disorder specialists, said James Beck, director of research programs at the Parkinson’s Disease Foundation.

“The ability to have a biomarker for Parkinson’s disease would be fantastic,” Beck said.

Since her Parkinson’s diagnosis, Christopher said she lost her sense of smell, her ability to write well and has developed a lurch in her walk.

“It’s a slow death because gradually you lose these abilities,” Christopher said. “You’re not the same person you were when you were younger.”

Tuite is Christopher’s physician and referred her to the study. She has taken a cognitive test and had her blood drawn already. Christopher said she isn’t looking forward to having her spinal fluid drawn, but her body can handle it.

“I just feel very strongly about it,” Christopher said. “Because we’re not gonna make any gains if people don’t participate.”

The information collected in the two-year study could be applied to future research, Tuite said, including local studies at the University.

Cloyd said he is researching how N-acetylcysteine, a commonly used antioxidant known as NAC, can be used on Parkinson’s patients to prevent brain cell damage.

His research team injected NAC directly into the patient’s veins to successfully increase antioxidants in the brain, but Cloyd said his new study involves giving NAC to patients orally, which he said is more practical.

New biomarkers could be used to track improvements in patients using NAC, Cloyd said.

Tuite’s team is still looking for more study participants who have had the disease for more than five years and volunteers who don’t have Parkinson’s or immediate relatives with the disease.

Christopher said she hopes to continue volunteering in research studies for as long as she can.

“I think in this century we’ll probably conquer most of these neurological diseases … like Parkinson’s.”