New lab test could help improve earlier diagnosis of Parkinson’s

Latest study results show a new test could help diagnose Parkinson’s before damage occurs to brain cells.

At the moment, there’s no definitive test to confirm a Parkinson’s diagnosis. This means that currently, it’s estimated that 26% of people with Parkinson’s are misdiagnosed at first. A simple diagnostic test for Parkinson’s would help people have a smoother diagnosis, allowing them to get information, support and access to treatments and therapies more quickly.

What does the new test do?

The lab test involves taking a sample of cerebrospinal fluid (CSF), a clear liquid that surrounds the brain and spinal cord, via an injection into the spine called a lumbar puncture. 

The research team then uses this to look for a protein called alpha-synuclein. In Parkinson’s, clumps of a misfolded form of the alpha-synuclein protein can be found. This toxic form of the protein can damage dopamine-producing cells and may be responsible for the development and spread of the condition in the brain.

What do the results show?

The team studied samples taken from 1,123 people who had signed up to take part in the Parkinson's Progression Markers Initiative (PPMI), led by the Michael J Fox Foundation. This study is helping identify early signs and progression of the condition. It includes people with and without Parkinson’s, including some with genetic mutations that have been linked to Parkinson’s. Read more about the PPMI study on The Michael J. Fox Foundation website.

Some of the people in the study had a diagnosis of Parkinson’s. Others experienced some early symptoms of Parkinson’s but did not have a formal diagnosis. In these people, there was no evidence of damage to brain cells via brain imaging in the region which is used to help diagnose Parkinson’s.

Results from the study showed that the test was able to correctly show a diagnosis of Parkinson’s with 88% accuracy overall. This included being able to diagnose Parkinson’s in people who had early symptoms but no diagnosis.

This suggests that the misfolded forms of alpha-synuclein are already present in the CSF before there is any observable damage to the brain cells that produce dopamine. This is exciting, as it could allow for earlier diagnosis and, in future, the opportunity to use treatments that can slow or stop the damage before it leads to significant symptoms.

Read a summary of the results on The Lancet website.

What happens next?

The results so far are promising. But we need to see larger studies including more people to know if this test is accurate. This will also help us understand if it can be used as a diagnostic test. Being able to detect Parkinson’s earlier could help improve the understanding of the causes of the condition, and uncover some important targets to develop better treatments.

Claire Bale, Head of Research Communications and Engagement at Parkinson’s UK, said:

"In Parkinson’s, the search for better treatments and a cure is severely hampered because we currently identify problems too late. By the time recognisable symptoms appear, major damage has already been done making it very difficult to stop or reverse the condition.

"We believe that a cure for Parkinson’s is possible. As with conditions like cancer and HIV where we’ve seen huge progress, early detection is going to be absolutely vital. 

"New detection techniques, such as the one being developed in this study, will hopefully soon provide a much better diagnosis experience for people with Parkinson’s, and in the future, allow us to stop, reverse or even prevent Parkinson’s."