In order to diagnose patients with Parkinson’s disease, physicians rely on clinical signs and symptoms. The problem, however, is that this method of diagnosing is not entirely accurate, which complicates clinical trials of potential treatments. Not to mention the fact that if a patient is diagnosed based on visible symptoms, it’s already too late to provide effective treatment as the brain damage has already been done.

Fortunately, it seems we are one step closer to an effective method of diagnosing Parkinson’s early. In a new study out of Iowa State University, scientists reported that they have developed a simple skin test that can accurately identify Parkinson’s disease.

As reported in the journal Movement Disorders, the study shows how a chemical assay can detect clumping of the protein alpha-synuclein in skin samples to help diagnose Parkinson’s disease. Using the assay can lead to earlier detection of Parkinson’s and better clinical trials, the researchers say.

To come to this conclusion, the researchers conducted a blinded study of 50 skin samples. Half of the skin samples came from patients with Parkinson’s disease and half came from people without neurologic disease. The protein assay correctly diagnosed 24 out of 25 Parkinson’s disease patients and only 1 out of 25 controls had the protein clumping.

Co-investigator of the study Thomas Beach says it is much more accurate than other diagnostic tools for early-stage Parkinson’s, which only deliver a correct diagnosis 50 to 70 percent of the time.  “Improving clinical diagnostic accuracy is, in my view, the very first thing we need to do in order to find new useful treatments for PD,” Beach says.

Although further skin sample tests must be done, the scientists hope this early diagnosis tool will allow physicians to trial therapeutic strategies designed to slow or prevent the development of advanced symptoms.